Microbiology Exam 4

Reduction of nitrogen ions such as nitrate by some bacteria is called

a) Deamination

b) Fermentation

c) Aerobic respiration

d) Denitrification

e) Nitrification

Denitrification

Formation of peptide bonds between amino acids to build a polypeptide would be called?

a) Glycolysis

b) Phosphorylation

c) Fermentation

d) Anabolism

e) Exergonic

Anabolism

Feedback inhibition, a negative feedback mechanism that regulates enzymes is best described as

a) Substrate binding to DNA, blocking enzyme transcriptase

b) Substrate binding to an enzyme in non-competitive site

c) Product binding to DNA, blocking enzyme transcription

d) Product binding to an enzyme in non-competitive site

e) None of the choices are correct

Product binding to an enzyme in non-competitive site

Denaturing an apoenzyme will destroy the 3-dimensional shape of protein, making it non-functional

a) True

b) False

True

Microbes can utilize only carbohydrates for energy production

a) True

b) False

False

During aerobic cellular respiration the final electron acceptor is

a) Cytochrome c

b) FAD

c) Nitrate

d) Pyruvic acid

e) Oxygen

Oxygen

ATP synthase is a complex enzyme needed for oxidative phosphorylation

a) True

b) False

True

Deamination is the removal of a ________ group

a) Carboxyl

b) Glycerol

c) Amino

d) Phosphate

e) Hydroxyl

Amino

Enzymes that are always present regardless of the amount of substrate are ________

a) Regulated enzymes

b) Apoenzymes

c) Exoenzymes

d) Endoenzymes

e) Constitutive enzymes

Constitutive enzymes

Which of the following is NOT involved in the step that occurs between the glycolysis and Krebs Cycle?

a) NADH is formed

b) CO2 is released

c) Pyruvic acid accepts electrons from NADH

d) Coenzyme A attaches to an acetyl group

Pyruvic acid accepts electrons from NADH

The reactions of fermentation function to produce _____ molecules for use in glycolysis is

a) NAD+

b) Glucose

c) Pyruvic acid

d) NADH

e) ATP

NAD+

All of the chemical reactions that occur within a cell are collectively referred to as metabolism, this would include ______ which are those reactions that use energy and synthesize building blocks in macromolecules and ______ which are the cellular reactions that break larger molecules into smaller molecules but also release energy.

a) Anabolism; amphibolism

b) Amphibolism; catabolism

c) Catabolism; anabolism

d) Anabolism; catabolism

Anabolism; catabolism

Enzymes are __________

a) used up in chemical reactions

b) proteins that function as catalysts

c) not needed for catabolic reactions

d) broken down in reactions that require energy input

e) All of the choices are correct

proteins that function as catalysts

Fatty acids can be converted to acetyl CoA for entering the Krebs cycle by the process of

a) Phosphorylation

b) Gluconeogenesis

c) Deamination

d) Amination

e) Beta-oxidation

Beta-oxidation

ATP molecules are catalysts that lower the energy activation needed to initiate a reaction

a) True

b) False

False

In 2017 the FDA banned the use of phenolic compounds such as triclosan in consumer soaps and lotions. This is due to _______

a) The inefficiency of phenolics as antimicrobials

b) A world-wide shortage of triclosan

c) Increased microbial resistance to these chemicals

d) They only work against bacterial cells, not fungi or viruses

Increased microbial resistance to these chemicals

In electron transport, the collective captured energy released by electrons is used to phosphorylate _________

a) Oxygen

b) ATP

c) NAD+

d) ADP

e) Pyruvic Acid

ADP

When a controlled agent targets the metabolic processes of microbial cells, active younger cells typically die more rapidly than older cells

a) True

b) False

True

A holoenzyme is a combination of protein and one or more substances called _________

a) substrates

b) cofactors

c) reactants

d) catalysts

e) apoenzymes

cofactors

Intermediates in the glycolysis pathway feed into additional pathways that make amino acids and complex carbohydrates, so the latter pathways are __________

a) Biosynthetic and exergonic

b) Hydrolytic and exergonic

c) Biosynthetic and endergonic

d) Hydrolytic and endergonic

Biosynthetic and endergonic

ATP is composed of deoxyribose, adenine, and three phosphate groups.

a) True

b) False

False

NADH that enters the electron transport system gives rise to a maximum of how many ATP?

a) 36

b) 38

c) 3

d) 2

e) 24

3

Each of the following is true of enzymes except _________

a) Their active site is specific to the substrate

b) They may or may not require cofactors

c) They can be used over and over again

d) They increase the initial energy required for a reaction to start

e) All of the choices are true of enzymes

They increase the initial energy required for a reaction to start

Placing organisms at 4 degrees is

a) Bactericidal

b) Sterilization

c) None of the choices are correct

d) Decontamination

e) Bacteriostatic

Bacteriostatic

Which of the following types of control agents would be used to achieve sterility?

a) Bactericide

b) Fungicide

c) Virucide

d) Sporicide

e) Germicide

Sporicide

A cleansing method that mechanically removes microbes and other debris to reduce contamination is _________

a) Antisepsis sterilization

b) Disinfection

c) Degermation

d) Sanitization

Sanitization

Ethylene oxide is a sterilizing gas

a) True

b) False

True

Phenols are useful antimicrobial compounds. They are effective against fungi and viruses. They disrupt several cellular targets, however they have been renewed from many consumer products because of the high toxicity and propensity to select for resistant strains.

a) True

b) False

True

Each of the following denaturing agents except _______

a) High temperature

b) Low temperature

c) Low pH

d) All of the choices are correct

Low temperature

Pasteurization does not kill endospores or thermoduric microbes

a) True

b) False

True

All of the chemical reactions of the cell are called ________

a) Catabolism

b) Redox reaction

c) Phosphorylation

d) Metabolism

Metabolism

The shortest length of time required to kill at least all test microbes at a specific temperature is the thermal death ______ whereas the lowest temperature required to kill all microbes in a sample within 10 minutes is the thermal death ______

a) point; time

b) window; point

c) time; temperature

d) time; point

time; point

The easiest microbial form to kill or inhibit

a) Mycobacteria and Staphylococci

b) Endospores

c) Prions

d) Vegetative bacteria and fungi

Vegetative bacteria and fungi

Chlorine compounds remain stable and effective in the presence of excess organic matter

a) True

b) False

False

Pseudomonas is resistant to soaps

a) True

b) False

True

Prions require more extensive methods of sterilization than are needed for bacterial endospores

a) True

b) False

True

Scrubbing or immersing the skin in chemicals to reduce the number of microbes on the skin is called ________

a) Sterilization

b) Sanitization

c) Disinfection

d) Ionization

e) Antisepsis

Antisepsis

The shortest time required to kill all microbes in a sample at a specified temperature is called ______

a) Sporicidal time

b) Thermal death point

c) Death phase point

d) Thermal death time

e) None of the choices are correct

Thermal death time

Sterilization is achieved by ______

a) Flash pasteurization

b) Boiling water

c) Steam autoclave

d) Hot water

e) All of the choices are correct

Steam autoclave

Which of the following is NOT used as an antiseptic?

a) 3% hydrogen peroxide

b) Iodophor betadine

c) Glutaraldehyde

d) Chlorhexidine

Glutaraldehyde

The fermentation process always produces alcohol as at least one of its products

a) True

b) False

False

Which pair of physical control methods will achieve complete sterilization?

a) Osmotic pressure and incineration

b) Ultraviolet radiation and filtration

c) Autoclaving and ionizing radiation

d) Freezing and filtration

e) Pasteurization and ultraviolet radiation

Autoclaving and ionizing radiation

Hydrogen peroxide can be used to sterilize instruments such as endoscopes

a) True

b) False

True

Select the organism that is least resistant to chemical and physical control

a) Protozoan cysts

b) Non-envelope viruses

c) Envelope viruses

d) Gram negative bacteria

e) Gram positive bacteria

Envelope viruses

A _____ would be used to destroy bacteria on a countertop, whereas _____ would be used on skin prior to making an incision

a) Antiseptic; sterilant

b) Antiseptic; disinfectant

c) Disinfectant; antiseptic

d) Sterilant; disinfectant

Disinfectant; antiseptic

______ is a control method that removes microorganisms rather than inhibiting or killing them

a) Boiling

b) Sterilization

c) Disinfection

d) Radiation

e) Filtration

Filtration