question

sum of all chemical reactions within an organism

answer

metabolism

question

catabolism

answer

The sum of all decomposition reactions within an organism. Exothermic reactions.

question

Anabolism

answer

The sum of all the synthesis reactions in an organism. Endothermic reactions.

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___ is the ability to do work

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Energy

question

energy that is stored; waiting to do work

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potential energy

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energy of motion, action, doing

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kinetic energy

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First Law of Thermodynamics

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Energy cannot be created or destroyed, but it can change form

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second law of thermodynamics

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every time energy changes form; there is an increase in entropy.

question

the measure of disorder; the amount of energy no longer available to do work

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entropy

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unusable energy, aka lost energy, is ____

answer

heat energy

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the amount of energy required to ____ is ___ released when the bond is broken

answer

form a bond; the same amount of energy (less that lost as heat)

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___ reactions are spontaneous reactions beacuse___

answer

catabolic; energy is released

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___ reactions are not spontaneous because ____

answer

anabolic; they require energy

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a series of anabolic or catabolic reactions is called a ___

answer

pathway

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cells have ___, which break larger molecules into smaller products

answer

catabolic pathways

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cells have ___, which form large molecules from the smaller products of catabolism.

answer

anabolic pathways

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when catabolic pathways break down large molecules ____.

answer

they release energy, therefore they are exergenic.

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Cells store some of the released energy in ___, though much is ___.

answer

the bonds of ATP; lost as heat

question

another result of the breakdown of large molecules by catabolic pathways is the production of numerous smaller molecules, some of which are ___.

answer

precursor metabolites

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some organisms such as e coli can synthesize everything in their cells from just ____

answer

precursor metabolites

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Catabolic pathways, but not necessarily individual catabolic reactions, may produce ____

answer

ATP, metabolites, or both

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Because building anything requires energy, anabolic pathways are ___

answer

endergonic

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anabolic reactions require ___

answer

more energy than they release

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the energy required for anabolic pathways usually comes from ___

answer

ATP molecules produced during catabolism.

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___ involves pathways that break down macromolecules to supply molecular building blocks and energy in the form of ATP

answer

catabolic pathways

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____ use the building blocks and ATP to synthesize macromolecules needed for growth and reproduction

answer

anabolic pathways

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metabolic reactions that involve the transfer of electrons from a molecule that donates an electron are called ___

answer

oxidaion reduction reactions, or redox reactions

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OILRIG

answer

Oxidation Involves Loss Reduction Involves Gain.

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electron acceptor is said to be ___ because

answer

reduced; their gain in electrons reduces their overall electrical charge.

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molecules that lose electrons are said to be ___ because ___

answer

oxidized; frequently their electrons are donated to oxygen atoms.

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Reduction and oxidation reactions always happen ___

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simultaneously

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A molecule may be reduced 2 ways:

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1. gaining either a simple electron
2. gaining an electron that is part of a hydrogen atom

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A molecule may be oxidized three ways

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1. losing a simple electron
2. by losing a hydrogen atom
3. gaining an oxygen atom with its electrons

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Electrons rarely exist freely in the ___; instead they ___

answer

cytoplasm; orbit atomic nuclei

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cells use ___ to carry electrons

answer

electron carrier molecules

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3 important electron carrier molecules

answer

1. NAD+ 2. NADP+ 3. FAD

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one of the electrons carried by nad+ or nadp+ is part of a ___; forming ___

answer

hydrogen atom; NADH and NADPH

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FAD carries ___ as hydrogen atoms as ___

answer

two electrons; FADH2

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Nutrients contain energy, but that energy is spread throughout their chemical bonds and is generally ___

answer

not concentrated enough for use in anabolic reactions

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During catabolism, organisms release ___

answer

energy from nutrients that can then be concentrated and stored in high energy phosphate bonds of molecules such as atp

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process by which inorganic phosphate is added to a substrate

answer

phosphorylation

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phosphorylation converts ADP to ___

answer

ATP

question

involves the transfer of phosphate to ADP from another phosphorylated organic compound

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Substrate level phosphorylation

question

process in which energy from redox reactions of respiration is used to attach inorganic phosphate to ADP

answer

oxidative phosphorylation

question

process in which light energy is used to phosphorylate ADP with inorganic phosphate

answer

photophorylation

question

After ADP is phosphorylated to produce ATP, anabolic pathways ___

answer

use some energy of ATP by breaking a phosphate bond

question

the cyclical interconversion of ADP and ATP functions somewhat like ___

answer

rechargeable batteries

question

ADP molecules can be recharged ___

answer

to ATP again and again

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In catabolic reactions, a bond must be ___ before it will break

answer

destabilized

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In anabolic reactions, reactants must ___ before bonds will form between them

answer

collide with sufficient energy

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In anabolism, increasing ____ increases the number of collisions and produces more chemical reactions

answer

either the concentrations of the reactants or ambient temperatures

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In living organisms, neither reactant concentration nor temperature is ___

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usually high enough to ensure that bonds will form

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The chemical reactions of life depend upon ___

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catalysts

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chemicals that increase the likelihood of a reaction but are not permanently changed in the process

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catalysts

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Organic catalysts are known as ___

answer

enzymes

question

the names of enzymes usually end with the suffix ___, and often incorporate the name of the enzymes __

answer

-ase; substrate

question

the molecule that an enzyme acts upon

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substrate

question

these enzymes catabolize molecules by adding water in a decomposition process known as hydrolysis

answer

hydrolases

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enzymes used primarily in the depolymerization of macromolecules

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hydrolases

question

rearrange the atoms withing a molecule but do not add or remove anything (so they are neither catabolic or anabolic)

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isomerases

question

enzymes that join two molecules together (and are thus anabolic)

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ligases or polymerase

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enzymes that often use energy supplied by ATP

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ligases or polymerases

question

split large molecules (and are thus catabolic) withous using water in the process

answer

lyases

question

enzymes that remove electrons (oxidize) from or add electrons (reduce) to various substrates

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oxidoreductases

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oxioreductases are used in ___ pathways

answer

both catabolic and anabolic

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enzymes that transfer functional groups (such as amino groups, phosphate groups, or two carbon groups) between molecules

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transferases

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Transferases can be ___

answer

anabolic

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The protein portion of protein enzymes that is inactive unless bound to one or more cofactors

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apoenzymes

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Inorganic ions or organic molecules that are essential for enzyme action.

answer

cofactor

question

all are either vitamins or contain vitamins, which are organic molecules that are required for metabolism but cannot be synthesized by certain organisms

answer

coenzymes

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some ___ bind with inorganic cofactors, coenzymes, or both

answer

apoenzymes

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the binding of an apoenzyme and its cofactor(s) forms an active enzyme called a ___

answer

holoenzyme

question

not all enzymes are proteinaceous, some are ___

answer

RNA molecules called ribozymes

question

In eukaryotes, they process other RNA molecules by removing sections of RNA and splicing the remaining pieces together

answer

ribozymes

question

functional core of a ribosome is a riboenzymes, therefore ___

answer

given that ribosomes make all proteins, ribosomal enzymes make protein enzymes

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enzymes catalyze reactions by ___

answer

lowering the activation energy needed to trigger a chemical reaction

question

Whereas heat can provide energy to trigger reactions, the temps needed to reach Ea for most metabolic reactions are often to high to allow cells to survive, so ____

answer

enzymes are needed if metabolism is to occur. This is true regardless of whether the enzyme is s protein or RNA, or whether the chemical reaction is anabolic or catabolic

question

The activity of enzymes depends on the ____

answer

closeness of fit between the functional sites of an enzyme and its substrate

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The shape of an enzymes functional site is called its ___

answer

active site

question

the active site is ______ of the substrate

answer

complementary to the shape

question

Generally, the shapes and locations of only ____ or ___ determines the shape of an enzyme's active site

answer

a few amino acids; nucleotides

question

A change in a single component of an enzyme - for instance through mutation - can render an enzyme ____

answer

less effective or even completely nonfunctional

question

____, which is critical to enzyme activity, has been likened to the fit between a lock and a key

answer

enzyme substrate specificity

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enzymes ____ when they bind to their substrate

answer

change shape slightly

question

The lock and key analogy of enzyme substrate specificity is called the ____

answer

induced fit model

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Some enzymes appear to bring ___ into sufficiently close proximity to ___

answer

reactants; enable a bond to form

question

other enzymes change the ____, inducing ____

answer

shape of a reactant; a bond to be broken

question

Many factors influence the rate of enzymatic reactions, including:

answer

temp, pH, enzyme and substrate concentrations, and the presence of inhibitors

question

the active sites of enzymes change ___ as ___.

answer

shape; temperature changes

question

If the temp rises to high, or falls to low, an enzyme ____

answer

is often no longer able to achieve a fit with its substrate

question

The optimum temperature for the enzymes in the human body is ___.

answer

37 degrees Celsium

question

organisms that grow best at temperatures above 80 celsius

answer

hyperthermophiles

question

If the temperature rises beyond a certain critical point, the ____ within an enzyme will break and the enzyme will ___

answer

noncovalent bonds (such as hydrogen and amino acids); denature

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___ enzymes lose their specific 3-D structure, so they are no longer functional

answer

Denatured

question

Denaturation is said to be ___ when an enzyme cannot regain its original 3-D structure once conditions return to normal

answer

permanent

question

In other cases, denaturation is ___ - the denatured enzyme's noncovalent bonds reform upon the return of normal conditions

answer

reversible

question

Extremes of __ also denature enzymes when ions released from ___ and ___ interfere with ____ and distort and disrupt an enzyme's secondary and tertiary structures.

answer

pH; acids; bases; hydrogen bonding

question

each enzyme has an optimal ___

answer

pH

question

Changing the __ provides a way to control the growth of unwanted microorganisms by _____.

answer

pH; denaturing their proteins

question

Another factor that determines the rate of enzymatic activity within cells is the ______

answer

concentration of substrate present

question

As substrate concentration increases, ____

answer

enzymatic activity increases as more and more enzyme active sites bind more and more substrate molecules.

question

eventually, when all enzyme active sites have bound substrate, _____

answer

the enzymes have reached their saturation point, and the addition of more substrate will not increase the rate of enzymatic activity.

question

enzymatic activity can be influenced by a variety of inhibitory substances that ___

answer

block an enzyme's active site

question

enzymatic inhibitors may be ___ or ___, and ____

answer

competitive; noncompetitive; do not denature enzymes

question

____ are shaped such that they fit into an enzyme's active site and thus prevent normal substrate from binding

answer

competitive inhibitors

question

competitive inhibitors do not undergo a ____ to form products

answer

chemical reaction

question

competitive inhibitors can bind ___ or ___ to the active site.

answer

permanently; reversibly

question

____ binding results in total loss of enzymatic activity; ___ competition can be overcome by an increase in the concentration of the substrate molecules, which increases the likelihood that active sites will be filled with substrate instead of inhibitor.

answer

permanent; reversible

question

noncompetitive inhibitors do not bind to the active site, but instead prevent enzymatic activity by ____

answer

binding to an allosteric site located elsewhere on the enzyme

question

binding at an allosteric site ____

answer

alters the shape of the active site so that the substrate cannot be bound

question

allosteric control of enzyme activity can take two forms:

answer

allosteric (noncompetitive) inhibition and excitatory allosteric control

question

____ halts enzymatic activity by binding at an allosteric that alters the shape of the active site to that the substrate cannot be bound

answer

allosteric (noncompetitive) inhibition

question

In ___, the binding of certain activator molecules to an allosteric site causes a change in shape of the active site, which activates an otherwise inactive enzyme

answer

excitatory allosteric control

question

cells often control the action of enzymes through ____

answer

feedback inhibition/negative feedback/end-product inhibition

question

allosteric feedback inhibition functions in much the way a ___

answer

thermostat controls a heater.

question

in metabolic feedback inhibition, the end product of a series of reactions is ____

answer

an allosteric inhibitor of an enzyme

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many organisms oxidize ___ as their energy source for anabolic reactions

answer

carbohydrates

question

Glucose is catabolized via one of two processes:

answer

1. cellular respiration
2. fermentation

question

a process that results in the complete breakdown of glucose to carbon dioxide and water

answer

cellular respiration

question

results in organic waste products

answer

fermentation

question

a process that catabolizes a single molecule of glucose to two molecules of pyruvic acid (pyruvate) and results in a small amount of ATP production

answer

glycolysis

question

both cellular respiration and fermentation begin with ____

answer

glycolysis

question

After glycolysis, respiration continues via the ___ and the ___, which results in a significant amount of ATP production

answer

krebs cycle; electron transport chain

question

Because it lacks the krebs cycle and the etc, ____ results in the production of much less ATP than does respiration

answer

fermentation

question

glycolysis is also called the ____, after the scientists who discovered it.

answer

embden-meyerhof pathway

question

___ is the first step in the catabolism of glucose via both respiration and fermentation

answer

glycolysis

question

glycolysis involves the splitting of a ___ into ____

answer

six carbon glucose molecule; two three carbon sugar molecules

question

when these three carbon molecules are ____, some of the energy released is stored in molecules of ATP

answer

oxidized to pyruvic acid

question

glycolysis occurs in the ____

answer

cytoplasm

question

The three stages of glycolysis

answer

1. energy investment stage
2. lysis stage.
3. Energy conserving stage

question

sum up what happens in glycolysis

answer

glucose is cleaved and ultimately transformed into two molecules of pyruvic acid. 4 ATPs are formed and two ATPs are used, so a net gain of two ATPs results. Two molecules of NAD+ are reduced to NADH.

question

in glycolysis, the high energy phosphate in PEP (one substrate) is transferred to an ADP molecule (second substrate) to form ___

answer

ATP

question

the direct transfer of the phosphate between two substrates is known as ___

answer

substrate level phosphorylation

question

In glycolysis, two ATP molecules are invested by substrate level phosphorylation to prime glucose for ___, and four molecules of ATP are produced

answer

lysis

question

2 alternative to glycolysis

answer

1. pentose phosphate pathway
2. entner-duodoroff pathway

question

___ is named for the phosphorylated pentose (five carbon) sugars

answer

pentose phosphate pathway

question

____ is primarily used for the production of precursor metabolites used in anabolic reactions, inculding the synthesis of nucleotides for nucleic acids, of certain amino acids, and of glucose by photosynthesis.

answer

pentose phosphate pathway

question

the pentose phosphate pathway also reduces _____ and nets ___

answer

two molecules of NAD+ to NADPH; a single moleculeof ATP from each molecule of glucose

question

____ is a necessary coenzyme for anabolic reactions that synthesize DNA nucleotides, steroids, and fatty acids

answer

NADPH

question

Most bacteria use glycolysis, and the pentose phosphate pathway, but a few substitue the ___ for glycolysis

answer

entner - duodoroff pathway

question

this pathway is a series of reactions that catabolize glucose to pyruvic acid using different enzymes from those used in either glycolysis or the pentose phosphate pathway

answer

entner-duodoroff pathway

question

only a very few bacteria use the entner duodoroff pathway, these include the gram negative ___ and ___

answer

pseudomonas aeruginosa; enterococcus faecalis

question

the entner duodoroff pathway nets ___

answer

only a single molecule of ATP for each molecule of glucose, but it does yield precursor metabolits and NADPH

question

___ is unavailable from glycolysis

answer

NADPH

question

glucose is ___ in glycolysis

answer

oxidized

question

after glucose is oxidized via glycolysis, or one of the alternate pathways, a cell uses the resultant ____ to complete either cellular respiration or fermentation

answer

pyruvic acid

question

a metabolic process that involves complete oxidation of substrate molecules and then production of ATP by a series of redox reactions

answer

cellular respiration

question

3 stages of cellular respiration

answer

1. synthesis of acetyl-CoA
2. the Krebs cycle
3. a final series of redox reactions - an electron transport chain - that pass electrons to a chemical not derived from the cells metabolism

question

Before pyruvic acid can enter the Krebs cycle for respiration, it must first be converted to ___

answer

acetyl-coenzyme A aka acetyl CoA

question

During the synthesis of Acetyl CoA, enzymes remove ___ and join ___ with a high energy bond.

answer

one carbon from pyruvic acid as Co2, the remaining two carbon acetate to Coenzyme A.

question

the removal of CO2 during the synthesis of Acetyle CoA is called ___, and requires a coenzyme derived from the vitamin ___. One molecule of ___ is also produced during this reaction

answer

decarboxylation; thiamine; NADH

question

Therefore, after the synthesis of Acetyl CoA, what has been produced

answer

two molecules of Acetyle CoA
two molecules of CO2
two molecules of NADH

question

___ is a series of eight enzymatically catalyzed reactions that transfer much of the stored to the coenzymes NAD+ and FAD.

answer

question

Krebs cycle, the two carbon atoms in acetate are ___, and the conenzymes are ___

answer

oxidized; reduced

question

where does the krebs cycle occur?

answer

prokaryotes: in the cytoplasm
eukaryotes: the matrix of mitochondria

question

the krebs cycle, aka ___, because many of its components have three carboxyl groups.

answer

tricarboxylic acid cycle

question

krebs cycle, aka ___, for the first compound formed in the cyle

answer

citric acid cycle

question

in the first step of the krebs cycle, the splitting of the high energy bond between acetate and coenzyme A releases enough energy to enable the binding of the freed two carbon acetate to a four carbon compound called oxaloacetic acid, this forms ____

answer

the six carbon compound citric acid

question

for every two carbon atoms that enter the krebs cycle, ___ are lost to the environment. At this junction in the krebs cycle, all six carbon atoms have been lost to the environment: two as ___, and four in ___

answer

two; CO2 molecules produced in decarboxylation of two molecules of pyruvic acid to form two Acetyl CoA molecules; four in CO2 molecules produced in decarboxylations in the two turns through the Krebs cycle (one molecule of Acetyl CoA enters the cycle at a time)

question

For every two molecules of Acetyl CoA that pass through the Krebs cycle, ____

answer

two molecules of ATP are generated by substrate level phosphorylation.

question

krebs cycle, redox reactions reduce ___, ___ for every two molecules of Acetyle CoA that move through the cycle.

answer

FAD to FADH2 and NAD+ to NADH

question

__ molecules of NADH and ___ molecules of FADH2 are formed in the Krebs cycle

answer

6, 2

question

the coenzymes are the most important molecules of respiration because they carry ____

answer

a large amount of energy that is subsequently used to phosphorylate ADP to ATP

question

the most significant production of ATP does not occur through glycolysis or the krebs cycle, but rather through the stepwise release of energy from a series of redox reactions known as ____

answer

an electron transport chain

question

an electron transport chain consists of a series of ____ molecules that pass electrons from one to another and ultimately to a _____

answer

membrane bound carrier; final electron acceptor

question

in etc, energy from the electrons is used to actively transport (pump) ___ across the membrane, establishing a ____, that generates ATP via a process called ___

answer

protons (H+); proton gradient; chemiosmosis

question

etc, ___ pass sequentially from one membrane bound carrier molecule to another, and eventually to a final electron acceptor

answer

electrons

question

etc, the electrons energy is used to pump ___ across the membrane

answer

protons (H+)

question

where are electron transport chains located?

answer

prokaryotes: cytoplasmic membrane
eukaryotes: inner mitochondrial membranes (cristae)

question

NADH and FADH2 donate electons as ___

answer

hydrogen atoms

question

etc, one molecule of ATP is produced for every ___

answer

two protons that cross the membrane

question

the 4 categories of carrier molecules in the electron transport chain

answer

1. flavoproteins
2. ubiquinones
3. metal-containing proteins
4. cytochromes

question

initial carrier molecule of electron transport chains of mitochondria

answer

flavoproteins

question

all carrier molecules in the etc alternate between ____

answer

the reduced and oxidized states

question

electrons carried by NADH enter the transport chain at a ___, and those carried by FADH2 are introduced via a ___. This explains why ____

answer

flavoprotein; ubiquinone; more molecules of ATP are generated from NADH than FADH2

question

in some organisms, the final electron acceptors are oxygen atoms, which with the addition of hydrogen atoms generates H2O; these organisms conduct ____ and are called ___

answer

aerobic respiration; aerobes

question

____ use other inorganic molecules instead of oxygen as the final electon acceptor and perform ____

answer

anaerobes; anaerobic respiration

question

in summary, glycolysis, the pentose phosphate pathway, the entner duodoroff pathway, and the krebs cycle strip electrons, which ___, from ___ molecules
and transfer them to _____. In turn, they _____. as the electrons move down the electron transport chain, ___ use the electons energy to ____ across the membrane

answer

energy; glucose; molecules of NADH and FADH2; pass the electrons to an electron transport chain; proton pumps; actively transport protons

question

____ is a general term for the use of ion gradients to generate ATP; that is ATP is synthesized utilizing energy released by the flow of ions down their electrochemical gradient across a membrane

answer

chemiosmosis

question

chemicals diffuse from areas of ___ to areas of ___ and toward an ____.

answer

high concentration; low concentration; electrical charge opposite their own.

question

the composite of differences in concentration and charge is called an ____

answer

electrochemical gradient

question

chemiosmosis uses the potential energy of an electrochemical gradient to ____

answer

phosphorylate ADP into ATP

question

even though chemiosmosis is a general principle with relevance to both ___ and ___, we consider it as it relates to ____

answer

oxidative phosphorlation; photophosphorylation; oxidative phosphorylation

question

energy carried by FADH2 is used to transport ___ fewer protons

answer

one third

question

because lipid bilayers are impermeable to protons, the transport of protons to one side of the membrane creates an electrochemical gradient known as the ____, which has potential energy known as a ____

answer

proton gradient; proton motive force

question

protons propelled by the proton motive force flow down their electrochemical gradient through protein channels, called ____, that phosphorylate molecules of ADP to ATP. such phosphorylation is termed ___

answer

ATP synthases (ATPases); oxidative phosphorylation

question

is termed this because the proton gradient is created by the oxidation of components of an electron transport chain

answer

oxidative phosphorylation

question

a prokaryote can theoretically yield ___ molecules of ATP

answer

38

question

the theoretical net maximum for eukaryotic cells is generally given as __ molecules of ATP

answer

36

question

why the difference in net ATP yield between prokaryotes and eukaryotes

answer

because the energy from two ATP molecules is required to transport NADH generated by glycolysis in the cytoplasm into the mitochondria.

question

summary of prokaryotic aerobic respiration of one molecule of glucose
Glycolysis
synthesis of acetyl CoA and Krebs cycle
ETC
1. ATP produced
2. ATP used
3. NADH produced
4. FADH2 produced

answer

Glycolysis: 4,2,2,0
Krebs cycle: 2,0,8,2
ETC: 34,0,0,0

question

Electrons cannot flow down an etc unless ___ are available to receive them

answer

oxidized carrier molecules

question

the partial oxidation of sugar (or other metabolites) to release energy using an organic molecule from within the cell as an electron acceptor.

answer

fermentation

question

the essential function of fermentation is the regeneration of ____ for glycolysis, so that ADP molecules can be phosphorylated to ATP

answer

NAD+

question

the major benefit of fermentation is that it allows _____

answer

ATP production to continue in the absence of cellular respiration

question

aerobic respiration
anaerobic respiration
fermentation
1. oxygen required
2. type of phosphorylation
3. final electon (hydrogen) acceptor
4. potential molecules of ATP produced

answer

aerobic: yes, substrate level and oxidative, oxygen, 36-38
anaerobic: no, substrate level and oxidative, NO3- SO4-2 CO3-2 or exogenous organic molecules, 2-36
fermentation: no, substrate level, endogenous organic molecules, 2

question

generally, proteins are too large to cross cytoplasmic membranes, so prokaryotes typically conduct the first step in the process of protein catabolism outside the cell by secreting ____

answer

proteases

question

enzymes that split proteins into their constituent amino acids

answer

proteases

question

reaction where special enzymes split off amino groups from amino acids once they are inside the cell.

answer

deamination

question

chemical formula for aerobic respiration

answer

C6H12O6 + 6O2 -> 6CO2 + 6H2O + 38/36 ATP
(ideal yield)

question

the ___ of a cell or virus is its entire genetic complement, including both its genes and nucleotide sequences that connect genes to one another

answer

genome

question

specific sequences of nucleotides that code for polypeptides or RNA molecules

answer

genes

question

nucleic acids are polymers of nucleotides each of which contains a ___, ____, and ___

answer

pentose sugar (deoxyribose or ribose), a phosphate, one of five nitrogenous bases

question

what are the five nitrogenous bases

answer

adenine, thymine, guanine, cytosine, and uracil

question

the five nitrogenous bases hydrogen bond in specific ways called ___

answer

base pairs

question

Complementary base pairs in DNA

answer

guanine and cytosine bond with one another with three hydrogen bonds.
adenine and thymine bond to one another with two hydrogen bonds.

question

base pair in RNA

answer

uracil bonds with adenine

question

the carbon atoms of deoxyribose are numbered ____

answer

1 prime - 5 prime

question

one end of a DNA strand is called the 5 prime end because ___

answer

it terminates in a phosphate group attached to a 5 prime carbon

question

the 3 prime end terminates with a ____

answer

hydroxyl group bound to a 3 prime carbon of deoxyribose.

question

one strand of DNA runs ___,and the other runs ___, scientists say they are ___

answer

3 prime to 5 prime, 5 prime to 3 prime, antiparallel

question

the DNA of prokaryotic genes is found in two structures:

answer

chromosomes and plasmids

question

prokaryotic cells package the main portion of their DNA, along with associated molecules of protein and RNA, as one or two distinct ____

answer

chromosomes

question

prokaryotic cells have a single copy of each chromosome and are called ___

answer

haploid cells

question

a typical bacterial chromosome consists of a circular molecule of DNA localized in a region of the cytoplasm called the ___

answer

nucleoid

question

no membrane surrounds a ___

answer

nucleoid

question

in addition to chromosomes, many bacterial cells contain one or more ___, which are small molecules that replicte independantly of the chromosome.

answer

plasmids

question

each plasmid carries info required for its own ___, and often for one or more ____

answer

replication; cellular traits

question

typically, genes carried on ___ are not essential for normal metabolism, growth, or cellular respiration, but can confer advantages to the cells that carry them.

answer

plasmids

question

types of plasmids

answer

fertility factors, resistance factors, bacteriocin factors, virulence plasmids.

question

eukaryotic genomes consist of both __, and ___ DNA

answer

nuclear; extranuclear

question

eukaryotic cells are often ___, which means they have two copies of each chromosome

answer

diploid

question

eukaryotic chromosomes are composed of DNA and globular proteins called ___

answer

histones

question

DNA, which has an overall negative charge, wraps around the positively charged histones to form beads called ___

answer

nucleosomes

question

in regions of the chromosome where genes are active, the chromatin fibers are loosely packed to form ____

answer

euchromatin

question

inactive dna is more tightly packed and is called ___

answer

heterochromatin

question

Nucleosomes clump with other proteins to form ___

answer

chromatin fibers

question

dna replication is an ____ that allows a cell to pass copies of its genome to its descendants

answer

anabolic polymerization process

question

polymerization processes require monomers and energy; ___ serve both functions in DNA replication

answer

triphosphate deoxyribonucleotides

question

the key to DNA replication is the ____ of the two strands

answer

complementary structure

question

in ___, a cell separates the two original strands and uses each as a template for the synthesis of a new complementary strand

answer

dna replication

question

biologists say that DNA replication is ___ because each daughter DNA molecule is composed of one original strand and one new strand

answer

semiconservative

question

dna replication begins at a specific sequence called the ___ . first, a cell removes ___, exposing the DNA helix. next an enzyme called ____ locally unzips the DNA molecule by ____, which exposes the bases in a ___. Other ___ stabilize the single strands so that they do not rejoin while replication proceeds.

answer

origin; chromosomal proteins; dna helicase; breaking down the hydrogen bonds between complementary base pairs; replication fork; protein molecules

question

After helicase untwists and seperates the strands, a molecule of an enzyme called ___ binds to each strand

answer

DNA polymerase III

question

DNA polymerases replicate DNA in only one direction ___

answer

5 prime to 3 prime

question

one new strand is synthesized continuously as a long chain of nucleotides and is called the ___

answer

leading strand

question

the other new strand is synthesized in short segments and is called the ____

answer

lagging strand

question

the leading strand and lagging strand are replicated ___

answer

simultaneously

question

synthesis of the leading strand proceeds continuously ___ the replication fork from a single ___ at the origin, following ___ and the ___ down the DNA

answer

toward; RNA primer;helicase and the replication fork

question

the lagging strand is synthesized ___ from the replication fork, discontinuously as a series of ___, each of which begins with its own ____

answer

away; okazaki fragments; RNA primer

question

bacterial dna replication is further complicated by ____ of the daughter strands, in which a cell adds a methyl group to one or two bases that are part of specific nucleotide sequences

answer

methylation

question

bacteria typically methylate ___ bases and only rarely a ___ base

answer

adenine; cytosine

question

methylation plays a roll in:

answer

control of genetic expression, initiation of DNA replication, protection against viral infection, and repair of DNA.

question

the ___ of an organism is the actual set of genes in its genome

answer

genotype

question

the ___ refers to the physical features and functional traits of an organism; including characteristics such as structures, morphology, and metabolism

answer

phenotype

question

___ determines phenotype by specifying what kinds of RNA and which structural, enzymatic, and regulatory protein molecules are produced

answer

genotype

question

process by which genetic information is copied as RNA nucleotide sequences

answer

transcription

question

process by which rna molecules in ribosomes then synthesize polypeptides

answer

translation

question

___ states that DNA is transcribed to RNA which is then translated into polypeptides

answer

central dogma

question

cells transcribe four main types of RNA from DNA:

answer

RNA primer, mRNA, tRNA, rRNA

question

molecules for DNA polymerase to use during DNA replication

answer

RNA primer

question

molecules which carry genetic info from chromosomes to ribosomes

answer

mRNA

question

molecules which combine with ribosomal polypeptides to form ribosomes

answer

rRNA

question

molecules which deliver amino acids to the ribosomes

answer

tRNA

question

___, the enzymes that synthesize RNA, bind to specific nucleotide sequences called ____

answer

RNA polymerases; promoters

question

In bacteria, a polypeptide subunit of RNA polymerase called the ___ is necessary for recognition of a promoter

answer

sigma factor

question

___ unwinds and unzips the DNA molecule in the promoter region and then travels along the DNA, unzipping the double helix as it moves

answer

RNA polymerase

question

a cell uses different ___ and ___ to provide some control over the relative amount of transcription.

answer

sigma factors; promoter sequences

question

___ with different sigma factos do not adhere equally strongly to all promoters

answer

RNA polymerases

question

like DNA polymerase, rna polymerase links nucleotides in the ___ direction only

answer

five prime to 3 prime

question

___ unwinds and opens DNA by itself; helicase is not required

answer

RNA polymerase

question

RNA polymerase does not need a ___

answer

primer

question

RNA polymerase is ___ than DNA polymerase

answer

slower

question

RNA polymerase incorporates ____ instead of deoxyribonucleotides.

answer

ribonucleotides

question

The ___ function of RNA polymerase is less efficeint than DNA polymerase

answer

proofreading

question

transcription ___ when RNA polymerase and the transcribed RNA are released from DNA

answer

terminates

question

self termination occurs when RNA polymerasse transcribes a terminator sequence of DNA composed of two symmetrical sequences:

answer

one that is very rich in guanine and cytosine bases, followed by a region rich in adenine bases.

question

___ termination depends on a termination protein that pushes that forces the RNA and DNA apart

answer

Rho dependent termination

question

eukaryotic cells transcibes RNA ____

answer

inside its nucleus

question

transcription in prokaryotes occurs in the ___

answer

cytosol

question

eukaryotes have ___ types of nuclear RNA polymerase

answer

three

question

eukaryotic cells must process mRNA before polypeptide translation, this involves three events:

answer

capping, polyadenylation, and splicing

question

___ is the process whereby ribosomes use the genetic info of nucleotide sequences to synthesize polypeptides composed of specific amino acid sequences

answer

translation

question

___ can be thought of as polypeptide factories

answer

ribosomes

question

triplets of mRNA nucleotides that code for specific amino acids

answer

codons

question

start codon

answer

AUG: codes for methionine in eukaryotes and fMET in prokaryotes

question

stop codons

answer

UAA, UAG, UGA

question

___ carries genetic info from a chromosome to the ribosome

answer

mRNA

question

3 ways eukaryotic mRNA differs from prokaryotic mRNA

answer

1) eukaryotic cells extensively process mRNA
2) a molecule of eukaryotic mRNA contains instructions for only one polypeptide.
3) in eukaryotic cells, transcription and translation do not occur simultaneously, it must leave the nucleus

question

a molecule of ___ transfers the correct amino acid to a ribosome during polypeptide synthesis

answer

tRNA

question

tRNA carries a specific amino acid and recognizes mRNA codons by matching them with ___ only for that amino acid

answer

Anti-codons

question

give the purpose, beginning point, and ending point for replication, transcription, and translation

answer

replication: to duplicate the cells genome, origin, origin or the end of a linear DNA molecule; Transcription: to synthesize RNA, promoter, terminator; translation: to synthesize polypeptides, AUG start codon, stop codons

question

___ is a method of translational control and is an RNA molecule complementary to a portion of mRNA, tRNA, or a gene

answer

short interference RNA

question

an ___ consists of a promoter and a series of genes which code for enzymes and structures such as channel proteins

answer

operon

question

some operons are controlled by an adjacent regulatory element called an ___ where a repressor protein binds to stop transcription

answer

operator

question

____ operons are not usually transcribed and must be activated by inducers

answer

inducible operons

question

___ operons are transcribed continuously until deactivated by repressors.

answer

repressible

question

the __ operon is an inducible operon. the ___, a protein encoded by a regulatory gene is constantly synthesized. when ___ is absent from the cells environment, the repressor binds to the operator thus blocking the movement of RNA polymerase and halting transcription. When lactose is present, ____

answer

lac, repressor, lactose, it acts as an inducer by inactivating the repressor so that it cannot bind to the operator thus allowing transcription to proceed.

question

the ___ operon is a repressible operon. the repressor is normally ___, whenever tryp is not present in the environment, the tryp operon is ___, when tryp is available ____

answer

tryp, inactive, active and the mRNA is transcribed and tryp is produced, it activates the repressor by binding to it which then binds to the operator thus halting the movement of RNA polymerase.

question

inducible operons regulate ___ pathways, while repressible operons regulate ___ pathways

answer

catabolic; anabolic

question

a ___ is a change in the nucleotide base sequence of a genome, particularly its genes

answer

mutation

question

mutation in which just one nucleotide base pair is affected. includes?

answer

point mutation; insertions deletions and substitutions

question

substitution of a nucleotide of similar shape, a purine for a purine or a pyrimidine for a pyrimidine.

answer

transition

question

substitution of a purine for a pyrimidine or vice versa

answer

transversion

question

which nucleotides are purines and which are pyrimidines

answer

purines: adenine, guanine
pyrimidines:cytosine, thymine, uracil

question

insertions and deletions are also called ___ because nucleotide triplets subsequent to the mutation are displaced, creating new sequences of codons.

answer

frameshift mutation

question

___ affect proteins much more seriously than mere substitutions because a frame shift affects all codons subsequent to the mutation.

answer

frameshift mutations

question

mutations can also involve ___, ___, or ___. such mutations and even larger deletions are called ____

answer

inversion, duplication, transposition, gross mutations

question

a ___ affects the genotype but not the phenotype

answer

silent mutation

question

a change in a nucleotide sequence resulting in a codon that specifies a different amino acid is called a ___

answer

missense mutation

question

a mutation that changes a amino acid codon into a stop codon

answer

nonsense mutation

question

this energizes electrons in atoms, causing some of the electrons to escape from their atoms

answer

ionizing radiation

question

____ refers to the exchange of nucleotide sequences between two DNA molecules often mediated by segments that are composed of identical or nearly identical nucleotide sequences called homologous sequences

answer

genetic recombination

question

many prokaryotes can acquire genes from other microbes of the same generation - a process termed ___

answer

horizontal gene transfer

question

cells that have the ability to take up DNA from their environment are said to be ___

answer

competent

question

4 methods of genetic recombination in bacteria

answer

conjugation, transduction, transposons, and transformation

question

involves the transfer of DNA from one cell to another via a replicating virus

answer

transduction

question

transduction can occur between

answer

prokaryotic cells or eukaryotic cells

question

a virus that infects bacteria is called a ___

answer

bacteriophage or phage

question

when a phage incorporates remaining fragments of DNA into its structure, it is termed a ____

answer

transducing phage

question

in generalized transduction, the transducing phage carries a ___ from a donor host chromosomes or plasmid to a ___

answer

random segment of DNA; recipient host cell

question

a method of genetic transfer in bacteria that requires physical contact

answer

conjugation

question

conjugation is mediated by ___ which are proteinacceous, rodlike structures extending from the surface of the cell

answer

conjugation pili

question

the gene coding for conjugation pili is located on a plasmid called an ___

answer

F plasmid or F factor

question

cells that contain an F plasmid are termed __, and cells that lack an F plasmid (recipient) are termed ___

answer

F+, F-

question

the cell that contains the conjugation pili is the ___

answer

F+

question

___ are segments of DNA that move themselves from one location in a DNA molecule to another location in the same or different molecule

answer

transposons

question

the result of the action of a transposon is termed ___

answer

transposition

question

In ___, a competent recipient prokaryote takes up DNA from its environment. competency is found naturally or can be created artificially in some cells

answer

transformation

question

Transformation requirements, state of donor, state of recipient

answer

free dna in the environment and a competent recipient, dead, living

question

Transduction requirements, state of donor, state of recipient

answer

bacteriophage, killed by bacteriophage, living

question

conjugation requirements, state of donor, state of recipient

answer

cell to cell contact and F plasmid, living, living

question

palindrome sequence found at each end of a transposon

answer

inverted repeat

question

a simple transposon consisting of no more than two inverted repeats and a gene that encodes the enzyme transposase

answer

insertion sequence

question

___ is the use of microorganisms to make useful products. Such products include bread, wine, beer, and cheese

answer

biotechnology

question

____ is a new type of biotechnology in which scientists change the genotypes and phenotypes of organisms to benefit humans

answer

recombinant DNA technology

question

___ are chemical and physical agents used to create changes in a microbes genome to effect desired changes in the microbes phenotype

answer

mutagens

question

the enzyme ___ transcribes DNA from an RNA template; genetic researchers use this to make ___

answer

reverse transcriptase; complementary DNA

question

___ cut DNA at specific nucleotide sequences and are used to produce recombinant DNA molecules

answer

restriction enzymes

question

in recombinant DNA technology, a ___ is a small DNA molecule that carries a particular gene and a recognizable genetic marker into a cell

answer

vector

question

___ allows researchers to replicate molecules of DNA rapidly

answer

pcr

question

___ is a technique for separating molecules by size, shape, and electrical charge

answer

gel electrophoresis

question

___ is the sequencing, analysis, and comparison of genomes

answer

genomics

question

scientists synthesize ___ by introducing genes for a pathogens polypeptides into cells or viruses

answer

subunit vaccines

question

___ can detect infections and inherited diseases before a patient shows any sign of disease.

answer

genetic screening

question

___ identifies unique sequences of DNA and is used in crime scenes, paternity tests, etc.

answer

genetic fingerprinting

question

___ cures various diseases by replacing defective genes with normal genes

answer

gene therapy

question

in ___ involving recombinant DNA technology, human genes would be inserted into animals to produce cells, tissues, or organs for introduction into the human body

answer

xenotransplants

question

___ plants and animals have been genetically altered by the inclusion of genes from other organisms

answer

transgenic

question

microbiologists typically use the term ___ when referring to an increase in population of microbes rather than an increase in size of an individual

answer

growth

question

an aggregation of cells arising from a single parent cell

answer

colony

question

three things all cells need for metabolism:

answer

1. a carbon source
2. a source of energy
3. a source of electrons or hydrogen atoms

question

organisms that utilize an inorganic source of carbon as their sole source of carbon are called ___, so named because they feed themselves

answer

autotrophs

question

___ catabolize reduced organic molecules they acquire from other organisms

answer

heterotrophs

question

organisms that acquire energy from redox reactions involving inorganic and organic chemicals are called ___

answer

chemotrophs

question

organisms that use light as their energy source are called ___

answer

phototrophs

question

organisms that acquire electrons from the same organic molecules that provide them carbon and energy are called ___

answer

organotrophs

question

organisms that acquire electrons or hydrogen atoms from inorganic sources are called

answer

lithotrophs

question

oxygen is essential for ___ because it serves as the final electron acceptor of etc, which produce most of the ATP in these organisms.

answer

obligate aerobes

question

oxygen is a deadly poison for __

answer

obligate anaerobes

question

4 toxic forms of oxygen

answer

singlet oxygen, superoxide radical, peroxide anion, hydroxyl radical

question

these prevent toxicity by removing the excess energy of singlet oxygen

answer

carotenoids

question

___ can maintain life via fermentation or anaerobic respiration, though their metabolic efficiency is often reduced in the absence of oxygen

answer

facultative anaerobes

question

___ do not use aerobic metabolism, but they tolerate oxygen by having some of the enxymes that detoxify oxygens poisonous forms

answer

aerotolerant anaerobes

question

this process reduces nitrogen gas to ammonia

answer

nitrogen fixation

question

together ___ make up more than 95% of the dry weight of cells

answer

carbon, hydrogen, oxygen, and nitrogen

question

elements that are required in very small amounts

answer

trace elements

question

organic molecules that organisms cannot synthesize but are required in small amounts

answer

growth factors

question

___ plays an important role in the 3-D structure of many types of biological molecules, and has different effects on the survival and growth of microbes

answer

temperature

question

the lowest temp at which an organism is able to conduct metabolism is called the ___

answer

minimum growth temperature

question

the highest temp at which an organism continues to metabolize is called the ___; when the temp exceeds this value, the organisms proteins are permanently denatured, and it dies

answer

maximum growth temperature

question

the temperature at which an organisms metabolic activities produce the highest growth rate is the ___

answer

optimum growth temperature

question

microbes that grow best at temps below 15 C and can even grow at temps below 0 C

answer

psychrophiles

question

organisms that grow best in temps ranging from 20C-40C

answer

mesophiles

question

because normal body temp is about 37 C, human pathogens are generally _

answer

mesophiles

question

___ organisms are mesophiles that can survive brief periods at higher temps

answer

thermoduric

question

___ grow at temps above 45 C in habitats such as compost piles and hot springs

answer

thermophiles

question

___ grow in water above 80 C; others can live at temps above 100 C

answer

hyperthermophiles

question

organisms are sensitive to changes in ___ because hydrogen ions and hydroxyl ions interfere with hydrogen bonding within the molecules of proteins and nucleic acids; as a result, organisms have ranges that they prefer and tolerate

answer

acidity

question

most bacteria and protozoa, including most pathogens, grow best in a narrow range around a neutral pH, which is ___; this is also the pH range of most tissues and organs in the human body

answer

6.5-7.5

question

organism that grow best in a neutral pH range are termed ___

answer

neutrophiles

question

___ are organisms that grow best in acidic habitats

answer

acidophiles

question

___ live in alkaline soils and water up to pH 11.5

answer

alkalinophiles

question

microorganisms require ___; they must be in a moist environment if they are to be metabolically active.

answer

water

question

___ is the diffusion of water across a semipermeable membrane and is driven by unequal solute concentrations on the two sides of such a membrane

answer

osmosis

question

the ___ of a solution is the pressure exerted on a semipermeable membrane by a solution containing solutes that cannot freely cross the membrane

answer

osmotic pressure

question

solutions with greater concentrations of such solutes are __ relative to those wile a lower concentration, which are ___

answer

hypertonic; hypotonic

question

shriveling up of the cells cytoplasm

answer

crenation

question

___ are adapted to growth under high osmotic pressure

answer

obligate halophiles

question

organisms that do not require high salt concentrations but can tolerate them

answer

facultative halophiles

question

organisms that live under extreme hydrostatic pressure are called ___

answer

barophiles

question

relationships in which one organism harms or even kills another organism are considered to be ___

answer

antagonistic relationships

question

In __ relationships, the individual members of an association cooperate such that each receives benefits that exceed those that would result if each lived by itself, even though each member could live seperately.

answer

synergistic

question

in __ relationships, organisms live in such close nutritional or physical contact that they become interdependent, such that the members rarely live outside the relationship

answer

symbiotic

question

___ are examples of complex relationships among numerous individuals, which are often different species, that attach as a group to surfaces and display metabolic and structural traits different from those expressed by any of the microorganisms alone

answer

biofilms

question

biofilms often form as a result of a process called ___, in which bacteria respond to the density of nearby bacteria

answer

quorum sensing

question

Cultures that are visible on the surface of solid media are called ___

answer

colonies

question

a __ is a sample of human material, such as feces, saliva, cerebrospinal fluid, or blood, that is examined or tested for the presence of microorganisms

answer

clinical speciman

question

___ are microorganisms associated with a certain area of the body without causing diseases

answer

normal microbiota

question

when warm agar media are poured into test tubes that are then placed at an angle and left to cool until the agar solidifies, the result is ___

answer

slant tubes or slants

question

a ___ is one in which the exact chemical composition is known

answer

defined medium aka synthetic medium

question

organisms that require a relatively large number of growth factors are termed ___

answer

fastidious

question

most chemoheterotrophs, including pathogens, are routinely grown on ___ that contain nutrients released by partial digestion of yeast, beef, soy, or proteins such as casein from milk.

answer

complex media

question

the exact chemical composition of a ___ is unknown because partial digestion releases many different chemicals in a variety of concentrations

answer

complex medium

question

___ contains a variety of nutrients, including growth factors, it can support a wider variety of different microorganisms.

answer

complex medium

question

____ typically contain substances that either favor the growth of particular microorganisms or inhibit the growth of unwanted ones.

answer

selective media

question

____ are formulated such that either the presence of visible changes in the medium or differences in the appearance of colonies helps microbiologists differentiate among different kinds of bacteria growing on the medium

answer

differential media

question

many media are both ___ and ___; that is they enhance the growth of certain species that can then be distinguished from other species by variations in their effect on the medium or by the color of the colonies they produce

answer

selective; differential

question

___ provide better anaerobic culturing conditions because they contain compounds that chemically combine with free oxygen and remove it from the medium

answer

reducing media

question

___ involves removing water from a frozen culture using an intense vacuum

answer

lyophilization

question

most unicellular organisms reproduce by ___, a process in which a cell grows to twice its normal size and divides in half to produce two daughter cells of equal size

answer

binary fission

question

growth at an exponential rate

answer

logarithmic growth or exponential growth

question

The time required for a bacterial cell to grow and divide is its ___

answer

generation time

question

a graph that plots the numbers of organisms in a growing population over time is known as a ___

answer

growth curve

question

During the ___, the cells are adjusting to their new environment; most cells do not reproduce immediately, but instead actively synthesize enzymes to utilize novel nutrients in the medium

answer

lag phase

question

growth phase during which the population increases logarithmically and the reproductive rate reaches a constant as DNA and protein synthesis are maximized

answer

log phase

question

Populations in ___ are more susceptible to antimicrobial drugs that interfere with metabolism

answer

log phase

question

eventually the number of dying cells equals the number of cells being produced, this is known as ___

answer

stationary phase

question

phase during which a population reaches a point at which cells die at a faster rate than they are produced

answer

death phase

question

direct methods of measuring bacterial growth:

answer

viable plate counts, membrane filtration, microscopic counts, and electronic counters, and most probable number

question

Indirect methods of measuring bacterial growth:

answer

metabolic activity, dry weight, and turbidity

question

reduction in the number of microorganisms and viruses; particularly potential pathogens on living tissues

answer

antisepsis

question

refers to an environment or procedure free of pathogenic contaminants

answer

aseptic

question

suffixes indicating destruction of a type of microbe

answer

-cide or -cidal

question

removal of microbes by mechanical means

answer

degerming

question

destruction of most microorganisms and viruses on nonliving tissue

answer

disinfection

question

use of heat to destroy pathogens and reduce the number of spoilage microorganisms in foods and beverages

answer

pasteurization

question

removal of pathogens from objects to meet public health standards

answer

sanitization

question

suffixes indicating inhibition, but not complete destruction, of a type of microbe

answer

-stasis and -static

question

destruction of all microorganisms and viruses in or on an object

answer

sterilization

question

scientists define ___ as the permanent loss of reproductive ability under ideal environmental conditions

answer

microbial death

question

___ kill all pathogens, including bacterial endospores

answer

high level germicides

question

the idea that an effective antimicrobial agent must be more toxic to pathogen than to the pathogens host

answer

selective toxicity

question

the ___ is the smallest amount of a drug that will inhibit growth and reproduction of the pathogen.

answer

minimum inhibitory growth (MIC)

question

the MIC is often determined via a ___

answer

broth dilution test

question

the lowest concentration of drug for which no growth occurs in the subcultures is the ___

answer

minimum bactericidal concentration (MBC)

question

Denaturation of proteins occurs as high temperatures break ____ bonds such as hydrogen bonds.

answer

noncovalent

question

a ribozyme is an enzyme made out of ___

answer

RNA

question

ATP is made by substrate-level phosphorylation only during ____.

answer

glycolysis and a small amount in the Krebs cycle

question

In feedback inhibition pathways, the end-product of the pathway is usually ____

answer

an inhibitor of the last enzyme in the pathway.

question

A(n) __________ is a type of enzyme that is capable of rearranging atoms within a molecule.

answer

isomerase

question

___ is a means by which a proton gradient is created, not used

answer

electron transport chain

question

Since most proteins are too large to cross the cytoplasmic membrane, prokaryotes begin protein catabolism by secreting __________ into their environment.

answer

proteases

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