Chapter 5&6 – Flashcards

Unlock all answers in this set

Unlock answers
question
Binary Fission
answer
An asexual process in bacterial and archaeal cells by which a cell divides to form two new cells while maintaining genetic constancy
question
Generation Time
answer
The time interval for a cell population to double in number
question
Incubation Period
answer
The time that elapses between the entry of a pathogen into the hose and the appearance of signs and symptoms
question
What are the phases of a population growth curve?
answer
Lag Phase- no cell divisions occur Log Phase- active stage of growth-primary metabolites are being synthesized Stationary Phase- reproductive and death rates equalize and plateau- environmental resistance is factors that limit population growth/secondary metabolites are produced these are chemicals not necessary for growth Decline Phase- nutrients become low and cells start dying off
question
Vegetative Cell
answer
Cells that actively metabolize and obtain nutrients
question
Endospore
answer
A dormant structure that persist during periods of unfavorable conditions
question
Dipocolinic Acid
answer
A chemical found in endospores that stabilizes its proteins and DNA
question
Sporulation
answer
Bacterial chromosome is replicated, One chromosome condenses, Asymmetric cell division partitions prespore from mother cell, Transverse septum forms and prespore is engulfed by mother cell, Cortex develops around the prespore followed by a piece of spore coat, Spore wall is complete; vegetative cell disintegrates, Free spore is released
question
Psychrophile
answer
A microbe that grows in cold temperatures
question
Mesophile
answer
A microbe that grows in moderate temperatures
question
Thermophile
answer
A microbe that grows in hot temperatures
question
Obligate Aerobe
answer
Requires O2 (Oxygen)
question
Obligate Anaerobe
answer
Cannot grow in the presence of O2 (Oxygen)
question
Facultative
answer
Can grow in the presence or absence of O2 (Oxygen)
question
Microaerophile
answer
Requires low concentrations of O2 (Oxygen)
question
Capnophile
answer
CO2 (Carbon Dioxide) loving organisms
question
Aerotolerant
answer
Anaerobe that can tolerate O2 (Oxygen) however does not derive any benefit from it
question
Halophile
answer
Lives in environments rich in salt
question
Hypotonic
answer
Solute concentration is lower than the cell. Water enters by osmosis. Cell becomes bigger
question
Isotonic
answer
Solute concentration is equal to that of the cell. Water is neither gained nor lost.
question
Hypertonic
answer
Solute concentration is higher than the cell. Water leaves by osmosis and the cell becomes smaller.
question
Synthetic Medium
answer
Chemically defined; contain highly purified organic and inorganic compounds.
question
Non-Synthetic Medium
answer
Also known as complex media contains at least one ingredient that is not chemically defined such as blood, serum, meat extract etc..
question
Carbon
answer
Serves as the backbone of organic molecules
question
Carbon Cycle
answer
Carbon enters the ecosystem by photosynthesis or chemoautotrophy and leaves by cellular respiration
question
Nitrogen
answer
Used for synthesizing proteins, DNA, RNA, and ATP
question
Nitrogen Cycle
answer
Nitrogen enters the ecosystem by nitrogen fixation and leaves by denitrification
question
Oxygen
answer
Major constituent of organic molecules, Required for aerobic cellular respiration
question
Hydrogen
answer
Major constituent of organic molecules, Involved in maintaining pH, Important for hydrogen bonding in macromolecules, Prime force in oxidation-reduction reactions of cellular respiration
question
Phosphorus
answer
Constituent of DNA, RNA, nucleotides, ATP, phospholipids, and coenzymes, PO43- is the primary inorganic source of the element
question
Sulfur
answer
Constituent of proteins, Cysteine and methionine are amino acids that contain sulfur
question
Microelements
answer
Compounds or substances needed in small amounts for proper functioning in the body.
question
Growth Factors
answer
Substances that cannot be synthesized and must be obtained as a nutrient such as temperature, oxygen, ph, hydrostatic and osmotic pressure
question
Fastidious Organism
answer
Require special growth factors
question
What are two major solidifying agents for media?
answer
Agar and gelatin
question
Which solidifying agent has the most disadvantages?
answer
Gelatin, it will not stay solid like agar it will melt
question
Synthetic Media
answer
Chemically defined; contains highly purified organic and inorganic compounds
question
Non-synthetic Media/Complex Media
answer
Contains at least one ingredient that is not chemically defined such as blood, serum, meat extract, infusions, milk, yeast extract, malt extract, soybean digests, and peptone
question
General Purpose Medium
answer
Designed to grow a broad spectrum of microorganisms such as TS broth, TSA, nutrient broth, and nutrient agar
question
Enriched Medium
answer
Enriched with blood, serum, hemoglobin, or special growth factors, Promotes the growth of fastidious organisms, Chocolate agar is an example
question
Selective Medium
answer
Contains a chemical that inhibits the growth of certain organisms, but promotes the growth of others, Lowenstein-jensen medium contains malachite green; this medium promotes the growth of mycobacterium while inhibiting other bacteria
question
Differential Medium
answer
Can grow several types of microorganisms, but can distinguish among them due to different appearances on the medium such as color of the colonies or color of the medium where the microorganisms are growing, Different types of gram-negative intestinal bacteria can be identified on chromacult agar due to the imparting of color to the colonies
question
Fermentation Medium
answer
Determines whether a microorganism can ferment a particular carbohydrate, Fermentation is an anaerobic process that often generates acids, If the carb is fermented acid is produced and can be detected by a ph indicator dye, Phenol red fermentation tubes turn yellow if the organism can ferment the sugar if it can’t it stays red
question
How can we isolate microorganisms in a mixed culture?
answer
By using the pour-plate method where the mixed culture is incubated on molten agar and after 24-48 hours the cells divide and form discrete colonies, or the streak-plate method where a series of streaks is made on the surface of nutrient agar of one area of the plate and dragged through all four sides after incubation each cell will grow to form a discrete colony on the plate
question
Turbidity
answer
Medium becomes cloudy as the number of microorganisms increase, this is measured with a spectrophotomer
question
Direct Count
answer
Involves counting the number of cells in a sample microscopically this is done with a cytometer
question
Viable Plate Count
answer
Determines the colony forming units of serially diluted samples using pour plate technique or spread plate technique
question
Most Probable Number
answer
A statistical estimation of the number of microorganisms by counting the number of tubes that demonstrate either turbidity or gas production
question
Filtration
answer
A known volume of liquid or air is passed through a filter that traps the microorganisms, A filter is placed on an agar medium and incubated the colonies are counted after the incubation period
question
What is are the differences between anabolism and catabolism?
answer
Anabolism is reactions that build up- buildup of small molecules, products are large molecules, mediated by enzymes, energy-requiring, Catabolism is reactions that break down- breakdown large molecules, products are small molecules, mediated by enzymes, energy releasing
question
What is a catalyst?
answer
A catalyst is a chemical agent that changes the rate of a reaction without being consumed in the reaction
question
What are the characteristics of enzymes?
answer
Enzymes are proteins that catalyze biochemical reactions, Enzymes are not consumed or permanently altered by the reaction, Enzymes are reusable, Enzymes exhibit specificity for their particular substrate, Enzymes are effective in low concentrations, Enzymes lower the energy of activation of a biochemical reaction, The names of enzymes typically end in the suffix -ase
question
Why are cofactors important for conjugated enzymes?
answer
Cofactors are organic or inorganic molecules that are required for the activity of a certain conjugated enzymes
question
Why is the active site important for enzyme function?
answer
An active site is the part of an enzyme that directly binds to a substrate and carries a reaction. It contains catalytic groups which are amino acids that promote formation and degradation of bonds. By forming and breaking these bonds, enzyme and substrate interaction promotes the formation of the transition state structure. Enzymes help a reaction by stabilizing the transition state intermediate. This is accomplished by lowering the energy barrier or activation energy- the energy that is required to promote the formation of transition state intermediate
question
What is an allosteric site? Why are they important for the regulation of metabolic pathways?
answer
An allosteric enzyme has a regulatory site as well as an active site. An inhibitory substance binds to the regulatory site and changes the shape of the enzyme distorting the active site. This prevents the substrate from binding to the active site inhibiting the enzymatic reaction.
question
Distinguish between competitive and non-competitive inhibitors.
answer
Competitive inhibitor is an inhibitor that binds to the avtive site it competes with the substrate for the active site but no product is made, Non-competitive inhibitor is an inhibitor that binds to another site where binding is irreversible
question
How do sulfa drugs work?
answer
Sulfa drugs act as competitive inhibitors of a bacterial enzyme. Bacteria need PABA in order to make metabolites leading to the making of folic acid which is necessary for DNA replication. Sulfa drugs out compete PABA. Since no product is made, no folic acid is made. The bacteria stop dividing because they are unable to perform DNA replication.
question
What factors can denature an enzyme?
answer
Denaturization occurs when there is an extreme change that causes the enzyme to become unstable and change its shape. The factors that can cause denaturization are temperature, pH, and osmotic pressure
question
Distinguish between exergonic and endergonic reactions
answer
Exergonic reaction is an energy releasing reaction- downhill to release energy to make ATP- catabolic, Endergonic reaction is an energy requiring reaction- uphill reaction- ATP needed for energy- anabolic
question
What are oxidation-reduction reactions?
answer
How cells transfer energy from one compound to another- always occurs in pairs- if one is oxidized a second is reduced- To remember oxidation and reduction; LEO the chemistry lion says GER! LEO: lose electrons oxidation, GER: gain electrons reduction
question
Explain the ATP cycle
answer
ATP is made by the phosphorylation of ADP: energy released from the oxidation of nutrient molecules provides the energy to make ATP
question
What is the role of coenzymes in cellular respiration?
answer
Coenzymes carries energy from the broken chemical bond of the substrate to the formation of the high energy bond of ATP Coenzymes act as mobile electron carriers, Coenzymes transport electrons to the electron transport chain where most of the ATP is made Most important coenzyme is NAD+
question
Summarize glycolysis
answer
Is a sugar splitting reaction that occurs in the cytosol of eukaryotic cell
question
Summarize the bridging step
answer
Step between glycolysis and citric acid cycle, Occurs in cytosol of eukaryotic cells, occurs twice for each molecule of glucose, pyruvic acid is converted into acetyl CoA, carbon dioxide is generated
question
Summarize the citric acid cycle
answer
Occurs twice for each molecule of glucose, occurs in the matrix of the mitochondrion or the eukaryotic cell and cytosol of the prokaryotic cell, carbon dioxide is generated, GTP is converted in ATP, the NADH and the FADH2 go to the electron transport chain
question
Summarize the electron transport chain
answer
A series of electron carriers bound to a membrane, occurs on the cristae of the mitochondrion of the eukaryotic cell and the mesosome of the prokaryotic cell, coenzymes drop off their electrons in the ETC, electrons are passed along a series of 9 carriers, oxygen is the terminal electron acceptor and is converted into water, as electrons are passed along the electron acceptors, energy is released to produce ATP
question
How many ATP molecules are made aerobically?
answer
38 ATPs for Prokaryotic 36 ATPs for Eukaryotic
question
Summarize how ATP is made by chemiosmosis
answer
Energy released in the electron transport chain is used to pump hydrogen across the membrane from the matrix into the intermembrane space.
question
What is anaerobic respiration? How many ATP molecules are made?
answer
Anaerobic respiration Is an energy releasing process that does not require oxygen, Anaerobic respiration is fermentation, only 2 ATPs are made
question
What is the function of fermentation?
answer
Fermentation pathway recycles coenzymes for ongoing glycolysis
question
Alcohol Fermentation
answer
Performed by fermentative yeasts, alcohol and carbon dioxide are produced
question
Homolactic Fermentation
answer
Produces lactic acid, performed by many bacteria, performed by our muscle tissue when oxygen levels fall
question
Heterolactic Fermentation
answer
Occurs in many bacteria, produces a comination of acids, also H2 and CO2
question
What is the methyl red test?
answer
Tests for acid products
question
What is the Voges-Proskauer test?
answer
Tests for neutral products
question
What is the difference between light-dependent and light-independent reaction?
answer
Light dependent needs light to react; light independent does not need light to react
question
Photoautotroph
answer
Needs co2 and light
question
Chemoautotroph
answer
Needs co2 and inorganic chemicals
question
Photoheterotroph
answer
Need organic molecules and light
question
Chemoheterotroph
answer
Need organic molecules and organic chemicals
question
What is the difference between a saprobe and a parasite?
answer
Saprobes feed on dead organic matter Parasites feed on living organic matter
Get an explanation on any task
Get unstuck with the help of our AI assistant in seconds
New