UNIT 2 STUDY GUIDEChapter 2.13 – 2.1.9

1. Describe the following bacterial structures and their functions: cell inclusions, endospores, fimbriae, pili, and flagella.– Cell inclusions are energy and/or carbon reserves (organic or inorganic materials)

• Found in prokaryotes• NOT organelles—may have a single membrane around them but not complex • Carbon is common storage inclusion- glycogen or PHB inclusion • Feasting they will fill up but in times of starvation they will use it up• phosphate, sulfur and nitrogen inclusions

» Sulfur globules: hydrogen sulfide is energy • Other inclusions= carbonate minerals, gas vesicles (bacteria can float) and magnetosomes (align

with earth magnetic field and get low in soil were low oxygen) – Endospore is a complex, dormant survival structures formed by some bacteria

• Various location in cell- species specific • Can survive under harsh conditions for an extended period of time & wait until they have optimal

conditions to germinate • Resistant to heat, radiation, chemicals, desiccation (cell dries out)

– Fimbriae filamentous proteins enable cells to stick to surfaces (numerous short little hairs) • Can form biofilms • Help pathogens stick to tissues

– Pilli filamentous proteins (LONGER than fimbriae); only find one or two per cell • Type IV pili -- twitch motility and DNA uptake/exchange • Sex pili – required for conjugation (genetic exchange between cells)

» HORIZONTAL gene transfer—donor cell has a pilus and attached to receptor cell, pulls it closer and sends a copy of plasmid through pilus to the other cell

» Formation of sex pili found in genes on plasmid» To see under light microscope virus is used as mordant

– Flagella threadlike appendages extending outward from plasma membrane • Functions: motility & swarming, attachment to surfaces, virulence factor (help burrow into host

tissues) » Adventurous motility = single bacteria move on its own» Social motility = group of bacteria move all together» Swarming bacteria = colony moves toward nutrients

• Arrangement» Monotrichous- one POLAR flagellum (typically bacilli)» Polar flagellum = flagellum at ONE END of the cell » Amphitrichous = “both” one flagellum at each end of cell » Lophotrichous = “tuft” cluster of flagella at one or both ends» Peritrichous = spread over entire surface of cell; may or may not be distributed evenly

2. Understand the structure and functions of bacterial endospores, the basics of sporulation and germination, and endospore resistance. – Endospore structure

• Exosporium—thin layer of protein; impermeable to a lot of toxins (protective outer layer)

• Spore coat – many layers of protein beneath the exosporium (spore specific)

• Cortex—added layer of peptidoglycan, loosely cross-linked peptidoglycan

• Core—like the cytoplasm; contains the core wall, cyctoplasmic membrane, cytoplasm, nucleoid and ribosomes

– When the endospore begins to germinate it loses the exosporium, coat, outer membrane and cortex– Resistance? The exosporium and spore coat (added layers of protein) is impermeable membrane for a lot of

toxins and other harsh conditions• The core contains dipicolinic acid and calcium – forms a complex and binds with free water inside

the endospore to dehydrate it; also stabilizes DNA by holding it together preventing from becoming denatured.

• Core contains very little water content (cytoplasm is gel like thus increasing heat resistance)• Core has a slightly more acidic pH • SASPS small acid-soluble spore proteins

» Only made during the sporulation process » Bind to DNA and protect DNA from heat and radiation

– The Life Cycle of an Endospore—vegetative cell no longer divides so signals growth of endospore (lack of nutrition is the trigger for sporulation). When the endospore detects nutrients and optimal conditions in the environment it loses its resistance and signals germination, returning back to a vegetative cell

• Sporangium—the cell making the spore – Stages in Endospore Formation (Bacillus species takes 8 hours) aka Sporulation

• Normal vegetative cells– growth stops lack of nutrients and spore is triggered to grow• Stage 1 - Unequal division inside the cell wall (no pinching or breaking apart)

» Commitment to sporulation • Stage II – septum forms and prespore begins to appear (cell wall in between membrane) • Stage III- Engulfment of prespore • Stage IV-- Cortex formation around prespore within mother cell • Stage V- Spore coat, calcium uptake, dipicolinic acid SASPs• Stage VI, VII -- Maturation and cell lysis• Free endospore.

– A true clone! It is a specialized cell division occurs in the cell. – Formation of Vegetative Cell

• Activation: preparation of spores for germination; heating, nutrients, oxygen and water stimulate• Germination: loss of resistant, nutrients detected, spores swell and rupture, increase metabolic act.• Outgrowth- emergence of vegetative cell; left with core, cell membrane and cell wall

3. Describe flagella structure and movement.– 3 parts: filament, Hook, Basal body (motor)

• Filament—composed of flagellin protein repeating units (15-20 nm long) » Determines shape and wavelength of flagella

• Hook—single protein that connects the filament to the motor at the base• Basal body/Motor—anchored in the cytoplasmic membrane and wall; central rod with a series of

rings » 4 rings in gram negative bacteria

• L—outer layer, lipopolysachharide • P – peptidoglycan • MS & C are in the cytoplasmic membrane

» 2 rings in gram positive bacteria because they lack outer membrane • MS & C

– Movement—energy for rotation is Proton Motive Force• Rotor: central rod and rings L, P, C, MS (collectively basal bod) • Stator: Mot proteins that surround the basal body, generate torque

– Proton moves through cytoplasm through Mot proteins exerting electrostatic forces. Attraction between positive and negative charged causes basal body to rotate as protons flow through Mot

– – Flagellum rotates like a propeller (up to 1100 revolution/sec)– 1000 protons are translocated/ rotation – Counterclockwise rotation—RUN– Clockwise rotation --- TUMBLE (close to a stop) – Paratrichous flagella bundle flagella in the area so they move

in the same direction for RUN• Tumble- flagella are pushed apart to initiate

clockwise motion to stop • Cannot run continuously or turn – run for aw while

then tumble when sense a change in environment • They can control over how long they run and

frequency of tumbles

4. Define chemotaxis and describe how bacteria move toward an attractant (or away from a repellent).– Chemotaxis—directed movements in response to chemicals foundn on cytoplasm membrane surface or

periplasm – Can move toward a chemical attractant (food, temperature) or away from a repellant (toxin)– Concentration of attractants & repellants deteched by chemoreceptors – Responses occur rapidly – Change length of run by tumbling (can’t turn)– Toward attractant—lowering the frequency of tumbles, run in direction of attractant; biased random walk– Away from repellant – opposite response of attractant

• Increasing frequency of tumbles, run away from repellant

5. Describe other types of motility (spirochete, twitching, and gliding).– Spirochete—flagella are in periplasm of cell; multiple flagella form an axial fibril which winds around the cell

• Exhibits flexing and spinning movements (good for burrowing)

– Twitching (type IV pili) • Pili at ends of cell cause short, intermittent, jerky motions

» Retraction of pili at one end moving like an inchworm pulling along. – Gliding—slower and smoother form of movement occurs along long axis of cell

• In contact with a solid/semisolid surface • Slim contact

– Flavobacterium—little protein feet ratcheting mechanism to move the cell along a surface• Glide proteins

Chapters 3.3 – 3.4, 3.6 – 3.13 6. Know the requirements for microbial survival and growth and their sources. (EEN)

• energy – work – Sunlight phototrophy – Oxidation of chemicals chemotrophy

» Organic- glucose, acetate (chemoorganotrophs)» Inorganic—hydrogen sulfide, ammonia, hydrogen (chemolithotrophs)

– conserved/stored in cells as ATP• electrons (hydrogen) – E production, reduction of Co2 to form organic molecules

– from oxidation of organic/inorganic chemical compounds• nutrients (carbon, hydrogen, oxygen) – synthesize organic building block for growth & maintenance

– based on energy source- light or chemical– electron source- inorganic or organic– carbon source

7. Define and recognize the major nutritional types of microorganisms based on their energy source, electron source, and carbon source. • ENERGY SOURCE

– Phototrophs- light– Chemotrophs- oxidation of chemicals

• ELECTRON SOURCE– Lithotrophs- reduce inorganic substances– Organotrophs- reduce organic compounds

• CARBON SOURCE– Heterotrophs (other feeders) – organic molecules for carbon– Autotrophs (self feeders) – carbon dioxide for carbon

» Obtain energy and electrons from other sources aka primary producers• First part of the word tells you energy source, second part tells you electron & last part tells you carbon

8. Define metabolism, catabolism, and anabolism. • Metabolism = total of all chemical reactions occurring in the cell • Catabolism = breaking things apart

– Fueling reactions– Energy conserving– Provide reducing power (electrons)– Generate precursors for biosynthesis

• Anabolism = building up – Synthesis of complex organic molecules from simpler ones– Required energy, electrons, and building blocks from fueling rxn (catabolism)

9. Understand the concepts of free energy (G) and standard free energy change ( Go).• Need Energy for active work

– Chemical work – synthesis of new chemical – Transport – take up nutrients, repair, replace, eliminate waste, maintenance

– Mechanical – motility, chemotaxis, chromosome replication and movement • G = free energy

– The amount of work that is available to do useful work • Delta G = change in free energy during a chemical reaction

10. Distinguish between exergonic and endergonic chemical reactions and their relationship to Go.• Exergonic releases energy (change in free energy is negative)

– Spontaneous • Endergonic requires energy (change in free energy is positive)

– Not spontaneous

11. Understand redox reactions including the standard reduction potential (E0) of half reactions, the redox (electron) tower, and their relationship to Go.• Redox reaction = electron transfer events; oxidation-reduction • Electron carriers are often used to transfer electrons from an electron donor to an electron acceptor• Can result in energy release, which can be conserved a

ATP or another energy rich compound• Oxidation- removal of an electron (or electron from a

substance• Reduction- addition of an electron (or electrons to a

substance) • Leo goes Ger • Oxidations and reductions frequency involve the transfer

of not just electrons, but both electrons plus a proton (H+)• Half reactions happen simultaneously (loss and gain of

electrons)• Standard Reduction Potential (E’0): equilibrium constant

for an oxidation-reduction reaction – A measure of the tendency of the reducing agent

to lose electrons – More negative—better electron donor– More positive better electron acceptor – **Electrons always flow from reduced compound

to oxidized compound • The greater the difference between E’0 of the donor and

E’0 of the acceptor the more negative the change in free energy is and the more energy that is released!**

• Electron Tower- oxidized form written on left, reduced form written on right (together they are a redox couple and have standard reduction potential

– Better electron donors on top…better electron acceptors at bottom (electrons fall down the tower)

» The further the electrons go down, the more energy is released (the greater the change in free E)

• This is why you get a lot more energy with aerobic respiration because electrons fall all the way to the body as oxygen is the best electron acceptor at the bottom of the tower.

» Light energy is used to drive electrons UP the tower during photosynthesis – Oxygen is the best known electron acceptor in nature, VERY bottom of the electron tower

12. Define the two classes of electron carriers.

• Coenzymes—freely diffusible; can transfer electrons from one place to another in the cell (NAD+)– Electron nannies with a minivan that drive electrons around cell and drop them off

• Prosthetic groups—firmly attached (fixed) to enzymes in the plasma membrane; function in membrane-associated electron transport reactions (ex. Cytochromes)

– Nannies that stay on the electron transport chain

13. Describe how NAD+/NADH and NADP+/NADPH carry electrons and their roles in metabolism. • NAD+/ NADP+ = nicotinamide adenine dinucleotide (phosphate)

– Coenzyme that can carry 2 electrons 1 H+ – Oxidized form

• NADH and NADPH are good electrons donors– Reduced form

• Reduction potential of redox couple is 0.32 V• NAD is involved in catabolism (break down)• NADP is involved in anabolism (build up)• NAD+ becomes NADH by donating its electrons to an acceptor because NAD+ again by accepting electrons

from a donor

14. Explain the importance of ATP.• ATP is the energy currency of the cell • 32 kJ/mole of energy is released when ATP is hydrolyzed to ADP + Pi• Endergonic reactions coupled to ATP breakdown – need break down ATP as a form of energy to perform the

reaction

15. Be aware of other high-energy compounds, and know the change in standard free energy requirement for cells to use them. • Phosphenlpyruvate• 1,3-Biphosphoglycerate• Acetly phosphate• Acetyl CoA

16. Compare and contrast substrate-level phosphorylation and oxidative phosphorylation. • Substrate-level phosphorylation

– Used in fermentation and other pathways– ATP is synthesized during steps in catabolism of an organic compound– Direct ADP to ATP—by the addition of phosphate

• Oxidative phosphorylation – Used in respiration – ATP is produced by proton motive force– Very indirect, involves electron transport chain and ATPase enzyme

17. Compare and contrast fermentation, aerobic respiration, and anaerobic respiration in bacteria.• Fermentation is a form of anaerobic catabolism in which organic compounds is both electron donor and

electron acceptor– uses an endogenous electron acceptor (originating from the cell) – Does not involve the use of an electron transport chain or PMF

• Aerobic respiration – form of catabolism in which the electron acceptor is oxygen (oxygen present) • Anaerobic respiration- form of catabolism in which the electron acceptor is an oxygen substitute (oxygen

absent)– Organic acceptors may also be used– Inorganic acceptors – NO, SO4, CO2, Fe, SeO4

• More ATP is produced in both respirations than in fermentation

18. Describe the process of fermentation, its functions, and its products.

• Takes place in the absence of an exogenous electron acceptor – oxygen is not needed• Uses pyruvate or derivative of as electron acceptor (pyruvate is reduced in process)

continues recycling of electron carriers (NADH from glycolysis is oxidized to NAD+– Need to get rid of electrons so it can pick up more in the next process

• Forms ATP via substrate level phosphorylation • There are various types of fermentation products- lactic acid, ethanol and mixed acid • Functions to reduce NADH to NAD+

19. Know why bacteria produce fermentation products and how these products are useful to humans.• Bacteria produce fermentation products• Kinda waste, like they don’t need the actual products• They use the products to recycle the electron carriers (NAD)

20. Distinguish between homolactic and heterolactic acid fermentation.• Homolactic—ONLY make lactic acid

– Cheeses, sour cream, yogurt• heterolactic acid—make majority of lactic acid as product but other product too like CO2

– Sauerkraut, pickles, buttermilk and involved in preventing food spoilage

21. Distinguish between mixed acid and butanediol fermentation. • Mixed Acid Fermentation—end products are a variety of acids; use simultaneous pathways to make a bunch

– 1,5,8,9 (Methyl Red Test detects pH less than 5• Butanediol fermentation- Voges-Proskaur test to detect intermediate acetoin

– Non acidic fermentation

22. Explain the purpose of the MR-VP test and know how it works. • Methyl red tests for presence of acid by detecting pH. Vogues Proskaur test detects intermediate acetoin

23. Describe the location, organization and functions of the bacterial electron transport chain in aerobic respiration, including its role in ATP production.• Electron Transport chain – series of electron carriers that operate together

– Eukaryotes: located in inner mitochondrial membrane– Bacteria & archaeons: located in cytoplasmic membrane

• Functions: transfer electrons from NADH and FADH2 to a terminal electron acceptor, establishes PMF• Electrons flow from carriers with more negative E0 to carriers with more positive Eo• As electrons are transferred, energy is released to make ATP by oxidative phosphorylation

24. Describe how proton motive force is used in the formation ATP.• ATPase is located at the very end of the ETC, uses PMF to make ATP.

25. Explain the function of ATPase. • Protons are kicked out of the cell and come back in through ATPase, which makes ATP• It’s the smallest known cellular motor• Can also work in REVERSE can break ATP apart to generate PMF for things like flagellar movement or

active transport

26. Know the functions of proton motive force. 1. Can be used to generate ATP2. Can be used for flagella rotation 3. Can be used for active transport

27. Describe aerobic catabolism (overview). Aerobic Respiration:

o Process that can completely catabolize an organic molecule (glucose) to CO2 using1. Glycolytic pathway breaks glucose to make 2 pyruvate2. CAC/Kreb’s/citric acid cycle3. ETC with oxygen as final electron acceptor

Produces ATP and recycles electron carriers Exoenzymes: inducible can be turned off; break down food OUTSIDE of cell Endoenzymes: constitutive always on; break food down INSIDE cell Amphibolic pathways can break down or build; a lot of the enzymes are reversible

28. For aerobic respiration, explain where in the pathway ATP is produced (glycolysis, TCA cycle, and ETC), the methods of ATP production used for each ATP generated, the electron carriers used, and the number of ATPs produced (during the process and the final net yield).

Glycolysis produces pyruvic acid, which is then converted to acetyl CoA (the bridge step). Acetyl CoA then enters the citric acid cycle. Electron carriers bring electrons from the first three steps to the electron transport chain where ATP is made via oxidative phosphorylation.

38 TOTAL ATP made from one glucose 34 from oxidative phosphorylation 4 from substrate level phosphorylationGlycolysis Bridge step Kreb’s

SLP 2 ATP 2 NADH 6 ATP

(oxidative phos.)

2 NADH 6 ATP via oxidative phosphorylation

6 NADH 18 ATP via oxidative phos. 2 FADH 4 ATP via oxidative phos.SLP 2 ATP

Chapter 5.1 – 5.6, 5.8 – 5.16 29. Describe the growth of bacterial cells (binary fission), including the cytoskeletal proteins involved and their

functions. Binary fission: creates 2 identical daughter cells

o Cell elongationo Chromosome is replicated and segregatedo Septum forms at midcello Cells divide

Cytoskeletal proteins:o FtsZ: Zippero ZipA:o FtsA: Anchor, holds Fts Z in place and holds divisome in placeo Fts I: Peptidoglycan synthesiso Fts K: helps separate chromosome to each sideo Min proteins: Min CD oscilates causing “interference” to FtsZ can’t come in until it’s time; Min E pushes

CD to the sides so FtsZ can only go in the middleo MreB: major in shape determining proteins (only in bacilli)

30. Define generation time, and be able to calculate it. Generation time: time it takes for population to double n= 3.3 (log Nt – log N0)

31. Describe in detail the four phases of bacterial growth observed in a batch culture.1. Lag : synthesis of new components to adapt to new environment; can vary in length2. Exponential: CONSTANT rate of growth; maximal rate of growth; Most cells are alive, they’re they healthiest in

this phase and most uniform

3. Stationary: Number of viable cells remain constant because metabolically active cells stop reproducing OR reproductive rate balanced by death rate; starting to run out of nutrients/oxygen

4. Death: total number of live cells is DECREASING

32. Be able to label a growth curve (cycle).

33. Describe the direct and indirect methods of measuring cell number (microscopic count, plating methods, turbidity measurements). Understand the advantages and disadvantages of each method.

Direct :o Total cell counts using counting chamber or electronic counter

Errors: could count dead cells tooo Viable cell counts: plating techniques or membrane filter

Errors: counting mistakes, incorrect media, could kill cells Indirect :

o Dry weighto Turbidity

Error: could count dead cells

34. Describe how temperature, pH, water activity, and oxygen affect microbial growth.TEMPERATURE:

pH:Acidophiles: optimum less than 5.5Neutrophiles: MOST bacteria; between 5.5 and 8Alkalophiles: greater than 8

WATER:

OXYGEN:

a. Obligate aerobe b. Obligate anaerobe c. Facultative anaerobe d. microaerophile e. Aerotolerant

35. Be able to name, recognize, and define the types of microorganisms that grow in various environments, and know the adaptations they have made to live there.

36. Explain how microorganisms protect themselves from the toxic products of oxygen reduction.Cells protect themselves from free radicals by using protective enzymes

1. Superoxide dismutase Produces oxygen2. Catalase produces oxygen3. Peroxidase NO oxygen in production

Chapter 5.17 – 5.1938. Define the frequently used terms of microbial growth control.

Sterilization: o Destruction or removal of ALL VIABLE microorganisms, including endospores and viruseso Absolute, either sterile or noto Autoclave

Decontamination: o Removal of possible bacteriao No agent involved, involves things that bacteria might like, like food

Disinfection: o Killing, inhibition, or removal of PATHOGENIC microbeso NOT sterileo Disinfectants: Bleach, Lysol, hydrogen peroxide

Sanitization: o Reduction of microbial population to level deemed safe by public health standardso Sanitizerso Not as harsh as disinfectants

Antisepsis: o Prevention of infection of living tissueo Gentle disinfectants (like hydrogen peroxide) can be used as antiseptics

Chemotherapy: o Use of chemicals to kill or inhibit growth within host tissueo Antimicrobial drugs (antibiotics) most don’t kill bacteria, just stop growth

39. Describe the physical methods to control microorganisms (moist heat, dry heat, low temperature, UV radiation, ionizing radiation, filtration).

Moist heat:

o Effective because water is a good conductor of heato Gets it done faster and at lower temp.o Boiling does NOT sterilize (can’t kill endospores)o Autoclaving water under very high pressure and temp; STERILIZESo Pasteurization controlled heating below boiling; kills pathogens; does NOT sterilize

Dry heat: o Less effective than moist heato Requires higher temps and longer timeo Flaming

Radiation: o UV: causes thymine dimers in DNA (thymines bond irregularly making it weak or replication errors);

limited to surface sterilizationo Ionizing: beta, gamma, or X rays; penetrate deep

Filtration: o For solutions that are heat sensitiveo Only sterilizes if filter has defined pore size that prevents endospores from getting through

40. Know and describe the general characteristics of antimicrobial agents including the terms used to describe their action (-cidal, -static, MIC, MLC).

Cidal: chemical agent that KILLS pathogens and non-pathogens, not necessarily endospores Static: inhibits growth MIC: minimal inhibitory concentration; lowest concentration of drug that inhibits growth MLC: minimal concentration of drug that kills pathogen

41. Explain and understand the methods used to assay the antimicrobial activity of an agent. Dilution susceptibility test:

o Smallest amount of agent needed to inhibit the growth of test organism (MIC)o Broth from which microbe can’t be recovered is MLC

Disk diffusion tests:o Plate is inoculatedo Disks containing antibiotics are placed on plateo Diameter of zone of inhibition is measured to see which antibiotic prevents growth

42. Describe the conditions that influence the effectiveness of an antimicrobial agent. Population size Population composition (Gram positive/negative, old/young, persister cells, virus, biofilm) Concentration of agent Duration of exposure Temperature Local environment (organic matter is helpful to bacteria)

DISEASES*

Disease Cause Characteristics Route of transmission

Symptoms

Strep throat Streptococcus pyogenes (group A streptococcus)

Bacteria, Cocci, gram-positive, occur in chains or pairs

Airborne droplets or shared food and drink

Sore throat, fever, pus-filled tonsils, swollen cervical lymph nodes; NO cough, runny nose, or red eyes

Cholera Vibrio cholerae Bacteria, Gram-negative, comma-shaped (vibrio)

Fecal-oral route; contaminated food or water

Diarrhea (rice-water stool), nausea, vomiting, dehydration

Bacterial meningitis

Neisseria meningitis

Bacteria, Cocci, gram-negative, diplococcus (pairs)

Via saliva though coughing, sneezing, kissing, even freshwater

Fatigue, fever, headache, neck stiffness, coma, death in 10%

Lyme disease Borrelia burgdorferi

Bacteria, spirochete, “diderm” double membrane, not gram positive or negative

Bite from infected blacklegged (deer) tick

Bull’s-eye rash, fever, chills, sweats, muscle ache, fatigue, nausea and joint pain

Infectious mononucleosis

Epstein-Barr virus (EBV or human herpes virus)

Virus, double helix DNA

Oral transfer of saliva and genital secretions

Most people are infected and develop adaptive immunity; fatigue, fever, sore throat, swollen lymph nodes, enlarged spleen, swollen liver, sore neck

Gas gangrene Clostridium perfringens

Forms gas and secretes toxins, Bacilli, gram-positive

Direct contact with bacteria on open wound

Around wound, gas formation, blisters filled with red/brown fluid, foul smell, fever, pain around injury, pale skin, swelling

http://highered.mheducation.com/sites/0073375268/student_view0/index.html

Chapter 3Bacterial LocomotionChemotaxis in E. coli (first part only – omit the part discussing the

chemoreceptors involved)Bacterial (Endo) Spore Formation

http://highered.mheducation.com/sites/0073402400/student_view0/index.html

Chapter 11Electron Transport System and ATP SynthesisElectron Transport System and Formation of ATPHow Glycolysis WorksHow NAD+ Works How the Krebs Cycle Works (just watch for an overview)

Chapter 7Binary Fission

Practice Questions:Which one of the following could trigger sporulation in Clostridium botulinum?

A. Presence of essential nutrients such as sugars and amino acidsB. Anoxic conditionsC. The inability to divideD. A temperature of 37 degrees Celsius.

Which of the following statements is not true of a sex pilus?A. Some prokaryotic cells can make sex pili, which are hollow protein tubes that extend out from the cells into the

environment.B. A sex pilus is used for conjugation, which is a type of vertical gene transferC. The genes for making a sex pilus are usually found on a plasmidD. A bacterium that makes a sex pilus may donate DNA to another bacterium.

Hydrogen bacteria use H2 a their energy and sole electron source. These bacteria use CO2 as their carbon source. What nutritional classification would best describe the bacteria?A. photolithoautotrophsB. photoorganoheterotrophsC. ChemolithoautotrophsD. chemoorganoheterotrophs

Which molecule in a redox couple will likely serve as the electron acceptor in a reaction with a redox couple that has a more negative standard reduction potential (E’0)?A. the reduced oneB. the oxidized oneC. the one with more hydrogensD. Based on the E’0, this couple would have the donor, not the acceptor.

Why do bacteria make fermentation products during the process of fermentation?A. to provide nutrient or growthB. for anaerobic ATP production C. to oxidize NADHD. All of the aboveE. No reason, they are waste products

In aerobic respiration (for one molecule of glucose), how many ATPs can be made in the Kreb’s cycle (including the bridge step) via the oxidation of NADH?

A. 0B. 2C. 18D. 24E. 38

Which of the following statements accurately describes the exponential growth phase of a bacterial population grown in a batch of culture?

A. The rate of bacterial growth is constantB. The reproductive rate is balanced by the death rate

C. The total number of viable cells remains constant.D. The rate of bacterial growth is gradually increasing as the bacteria adapt to environmental conditions

Which one of the following methods would be appropriate to use for determining the number of viable cells in a bacterial culture

A. Direct microscopic count using Petroff-Hausser Counting ChamberB. Cell mass measurement (dry weight)C. Turbidometric measurementD. Plate CountE. None of the above

Compared with antisepsis, disinfection is usuallyA. More aggressiveB. Less aggressive C. Equally aggressive D. Not aggressive