Microbiology Notes Exam 2 (Lectures 11 &12) – Flashcards
Unlock all answers in this set
Unlock answersWhere within the genetic code can a mutation happen? |
Anywhere in DNA! |
Do all mutations impact enzmyes? |
Not all mutations impact enzymes.
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What is the general function of all enzmyes? |
Enzymes are catalysts, they speed up reactions. |
The gene for the production of what enzyme is affected in a positive Ames test? |
The gene for histadine production is affected, or mutated, in a positive Ames test. |
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What is the process which converts glucose into pyruvate? How many enzymes are involved? |
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In the cookbook metaphor for DNA, what do we call the chapters which organize our genes into sections based on function? |
Operons
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Operons
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What structure are operons a part of? What is their relationship to genes? |
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What are the three distinct regions of an operon? |
P,O,G Promotor region, Operator Region, & Gene Region [image] |
What is the first region of an operon? What it the function of this region? |
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The OPERATOR, this is the second region, just after the promoter. [image] |
What is the function of the operator portion of the operon? |
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What is the second region of the operon? |
The second region of the operon, after the promoter, is the operator. This is the part of the operon that controls whether the genes are turned on or off. [image] |
What is the third region of the operator? |
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What is the relationship between the genes on a single operon? |
The genes on an operon code for one specific process. [image] |
In transcription of an operon, are the genes copied individually or all at once? |
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A start code. This is the genetic code's equivalent of a capital letter.
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What amino acid do stop codes call for? |
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What happens when the ribosome reaches a stop code? |
The polypeptide chain is released. |
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What type of code is the stop code? |
A nonsense code [image] |
What does a stop code indicate to the ribosome? |
The protein is done. |
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What do we call an operon which is always on? |
A constitutive operon |
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What do we call an operon that is always on, at least at a baseline level? |
A constitutive operon |
What is a constitutive operon? |
An operon that is always on, at least at a baseline level |
What type of enzyme is always present in the cell? |
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To what region of the operon does a repressor bind? |
A repressor binds to the operator region of an operon [image] |
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Are all enzymes proteins? Are all proteins enzymes? |
All enzymes are proteins. Not all proteins are enzymes. |
Why is it advantageous to a cell to utilize a repressor? |
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A repressor bound to the operator. [image] |
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In an inducible operon, what disables the repressor? |
In an inducible operon, the inducer disables the repressor. [image] |
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What is an inducible enzyme system? |
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What do we call the two types of genes or genetic components within the DNA? |
Structural genes and regulatory genes [image] |
What do we call the type of genes that code for some specific product of the cell? |
Structural genes [image] |
What are structural genes? |
Structural genes are genes that code for some particular product of the CELL. [image] |
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Structural genes, because insulin regulates cellular activity. Regulatory genes regulate DNA activity, not cellular activity. |
What type of gene would the information for producing porins be housed on? |
Structural genes. |
What type of gene would the information for producing enzymes be housed on? |
Structural genes |
What types of genes produce products that regulate DNA? |
Regulatory genes regulate DNA [only DNA] |
What do regulatory genes regulate? |
Regulatory genes produce products that regulate DNA activity. |
What do regulatory genes code for? |
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Is a repressor based on the same operon that it represses? |
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Is there always a regulatory gene to influence a given operon? |
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Do mammilian cells have operons? |
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Why are inorganic enviromental agents risky to the human body? |
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By what means do viruses cause cancer? |
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Are repressors always made by the cell? |
No. Repressors may be made by the cell, but they can also be enviromental agents or the byproduct of another process in the body. |
What do we call the system that characterizes an operon that usually on, but which can be turned off? |
A repressible system [image] |
What characterizes a repressible operon? |
A repressible operon is usually on, but can be turned off. |
In a repressible system, what is the most common origin of the repressor? |
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What are the three possible origins of repressors? |
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What is the most common origin of inducers? |
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What do we call the catalyst for biochemical reactions? |
Enzmyes! |
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Enzymes |
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By controlling biochemical reactions ____________ control the organism itself. |
By controlling biochemical reactions enzymes control the organism itself. |
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Inhibitors [ Competitive & Allosteric-or-noncompetitive] [image] |
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Are competative and allosteric inhibitors relevant to humans? |
Yes, allosteric and competative inhibitors are used regularly in human medicine. |
____________ are highly specific to a given substrate in that they only interact with one. |
Enzymes are highly specific to a given substrate in that they only interact with one. |
How many substrates will a given enzyme interact with? |
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What do we call the molecule that an enzyme interacts with? |
A substrate. [image] |
Do enzymes make reactions happen? |
NO! Enzymes are strictly rate alterers. They DO NOT make a reaction happen. |
What alters the rate at which reactions happen in a cell? |
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Do enzymes make reactions happen? |
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__________ speed up the rate at which reactions occur. |
Enzymes speed up the rate at which reactions occur. |
What happens to a reaction in the absense of an effecting enzyme? |
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A competitive inhibitor [image] |
What type of inhibition relies on a substrate look-a-like? |
Competitive inhibition [image] |
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What is the problem with competitive inhibitors? |
Competitive inhibitors are substrate concentration dependent. [image] |
Competitive inhibitors are __________________________ dependent. (two words) |
Competitive inhibitors are substrate concentration dependent. (two words) |
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The effectiveness of what mechanism is substrate concentration dependent? |
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If the concentration of the normal substrate is increased, what happens to the efficiency of the competitive inhibitor? |
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What do we call the type of inhibitor that binds to the enzyme at a site other than the active site in such a way that it either distorts or blocks the active site? |
An allosteric or noncompetitive inhibitor [image] |
What is a non-competitive or allosteric inhibitor? |
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Is an allosteric inhibitor substrate concentration dependent? |
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How are beta-blockers like allosteric inhibitors? |
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What effect do competitive inhibitors have on genotype? What effect do the competitive inhibitors have on phenotype? |
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What effect do allosteric inhibitors have on genotype? What effect do the allosteric inhibitors have on phenotype? |
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Catabolism ; Anabolism |
What do we call the enzyme regulated chemcial processes that release energy? |
Catabolism: the breakdown of complex molecules into simplier ones, often by hydrolysis, causing the release of energy. |
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What do we call enzyme regulated chemical reactions that require energy? |
Anabolism: the building of complex organic molecules from simplier ones |
What do we call the building up of complex organic molecules from simplier ones? |
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What is the process that starts metabolism? |
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By what process[es] do we make nonessential amino acids in the body? |
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What process, anabolism or catabolism, does our study of metabolism focus on? |
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What two essential components does catabolism give an organism? |
Energy in the form of ATP & a source of Carbon Skeletons or C' [c prime] |
What is the "gas that runs the biological show"? |
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What is the importance of the carbon skeletons garnered during catabolism? |
Carbon skeletons enable the build up of new carbon based molecules in anabolism. |
What is a carbon skeleton? |
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What two things do all cells require? |
Energy ; Carbon Skeletons |
In chemical terms, where is energy stored? |
In bonds. [image] |
What happens when chemical bonds are broken? |
Energy is released, and stored as ATP .
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What is ATP an acryonym for? |
Adenosine Triphosphate. [image] |
What is ADP and acronym for? |
Andosine diphosphate (see molecule at bottom of image) [image] |
What is the relationship between ATP and ADP? |
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What makes up a molecule of ATP? |
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Once ATP becomes ADP, can that ADP be transformed back to ATP? |
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Cellular Respiration, Fermentation, and Photosynthesis |
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Cellular Respiration, Fermentation, and Photosynthesis are all means of energy production and carbon skeleton garnering utilized by bacteria. |
Do all bacteria utilize cellular respiration and fermentation and photosynthesis to product energy and garner carbon skeletons? |
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Cellular Respiration |
Which part of cellular respiration is not acutally a pathway? |
The electron transport chain |
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Genetics. The energy producing and carbon generating pathway of any given organism is coded for in its DNA. |
Is each organism capable of a single biological pathway to energy production? |
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If an organism contains a photoactive or light sensitive pigment, what energy producing pathway are they likely to be capable of? |
PHOTOSYNTHESIS
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Are we able to switch between cellular respiration and photosynthesis or fermentation for our energy production? |
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What is the first process in the process of cellular respiration? |
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Is glycolysis an anaerobic or aerobic process? |
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What molecule is the starting point for glycolysis? |
Glucose [image] |
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The book uses pyruvic acid. Prof. M used both. |
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During what two transformation in glycolysis is a molecule of ATP used or spent? |
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What are the products of glycolysis? |
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How many molecules of ATP are generated during glycolysis? How many does the process net? |
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The cell removes intermediary products of cellular respiration prior to their reaching the end of cellular respiration to make use of their carbon skeletons. |
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The cell takes whatever intermediary most closely aligns with the product it is aiming to produce. |
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They all have carbon skeletons. [image] |
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What is the limiting factor in glycolysis? |
NAD+
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What pathway in cellular respiration can nonessential amino acids come out of? |
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NAD+ |
Is NAD+ readily available dietarily? |
No. |
Do we produce a large quantity of NAD+? |
Nope. |
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What happens in glycolysis if NAD+ becomes unavailble? |
Without NAD+ the pathway is shut down. No energy is generated. |
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A limiting factor |
What is a limiting factor? |
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When is glucose a limiting factor in glycolysis? |
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Why will glucose never be a limiting factor in glycolysis? |
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Not necessarily, sometimes less is produced, sometimes more is produced. |
What process keeps glucose from being a limiting factor in glycolysis? |
Gluconeogenesis |
How many molecules of ATP are PRODUCED during glycolysis? |
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By what process is ATP produced from ADP in glycolysis? |
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substrate-level phosphorylation [image] |
What process is shown in the image below? What part[s] of cellular respiration is this process used in? [image] |
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What type of phosphorylation occurs during glycolysis? |
Substrate-level phosphorylation [image] |
What do we call the type of ATP produced outside the electron transport chain? Note: This is the type produced in glycolysis and the Krebs cycle. |
Substrate phosphorulated ATP [image] |
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They have one of their carbons removed by oxidative decarboxylation [image] |
What is oxidative decarboxylation? What is its relationship to pyruvate? |
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What do we call the result of the oxidative decarboxylation of pyruvate? |
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From what is Coenzyme A derived? |
Coenzyme A is derived from Vitamin A |
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How many steps occur in the Kreb's Cycle? |
10! [image] |
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Substrate Phosphorulation or Substrate Level Phosphorulation (same thing) [image]
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What two electron carriers are utilized in the Kreb's Cycle? |
NAD+ and FAD |
Why is NAD in Kreb's Cycle not a limiting factor for the Kreb's Cycle? |
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What is the third process in cellular respiration? |
Electron Transport Chain. |
What is the second process in cellular respiration [not including oxidatative phosphorulation]? |
Kreb's Cycle |
Where does the Kreb's Cycle take place in prokaryotes? |
In the cytoplasm [image] |
How many proton pumps or channels are in the elctron transport chain? |
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HYDROGEN or H+ [image] |
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2 each, for a total of 6. p.127-9 [image] |
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How many protons [in the form of hydrogen ions] are pumped into the periplasmic space at the third proton pump?
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SINGLET OXYGEN! [image] |
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Chemiosmotic Gradient & Electrochemical Gradient [image] |
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What process(es) generate(s) the most ATP? a. Glycolysis b. Kreb's cycle ; Oxidatative Decarboxylation of Pyruvate c. Proton pumps d. Chemiosmosis e. Substrate level phosphorulation |
What process generates the most ATP? a. Glycolysis Net 2 per glucose molecule* b. Kreb's cycle & Oxidatative Decarboxylation of Pyruvate Net 2. No ATP is produced in the decarboxylation of pyruvate, only 2 NADH per glucose molecule* c. Proton pumps Proton pumps don't generate any ATP d. Chemiosmosis This is the gradient that activates the ATP synthase in the Electron transport chain. It produces 34 ATP - 3 for each of the 10 NADH produced and 2 for each of the 2 FADH2 produced. Again, this is per glucose molecule.* e. Substrate level phosphorulation This type of phosphorulation is active in both glycolysis and the Kreb's cycle. It is responsbile for the generation of 4 ATP per glucose molecule*
*All number are best case scenarios. |
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What part of cellular respiration produced the most energy? |
The electron transport chain. |
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Oxidative Phosphorylation [image] |
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There is no energy value difference between ATPs generated by different methods. They are chemically identical. |
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Oxidative Phosphorulation |
What is oxidative phosphorulation? |
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What does NAD+ come from? What does FAD+ come from? What are these? |
NAD+ is a derivative of the B vitamin niacin. FAD+ is a derivative of the B vitamin riboflavin. Both are coenzymes and electron carriers. |
Based on oxygen preference, who can run cellular respiration? |
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What do aerobic organisms need in order to run cellular respiration? |
Oxygen. |
What do anerobes require to run cellular respiration? |
Anerobes can run cellular respiration as long as oxygen is NOT present and a non-organic terminal electron acceptor is available. |
What three types of organisms, based on oxygen preference, are able to run cellular respiration? |
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What do facultative anaerobes require in order to run cellular respiration? |
The presence of oxygen. |