Content check — Microbiology, Chapter 8: Microbial Metabolism

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Chapter 8: Microbial Metabolism

52 problems · 0 figures

Which of the following is an organism that obtains its energy from the transfer of electrons originating from chemical compounds and its carbon from an inorganic source?

a.
chemoautotroph
b.
chemoheterotroph
c.
photoheterotroph
d.
photoautotroph

Answer

A. chemoautotroph

8-2 §8.MC source ↗

Which of the following molecules is reduced?

a.
NAD⁺
b.
FAD
c.
O₂
d.
NADPH

Answer

D. NADPH

8-3 §8.MC source ↗

Enzymes work by which of the following?

a.
increasing the activation energy
b.
reducing the activation energy
c.
making exergonic reactions endergonic
d.
making endergonic reactions exergonic

Answer

B. reducing the activation energy

8-4 §8.MC source ↗

To which of the following does a competitive inhibitor most structurally resemble?

a.
the active site
b.
the allosteric site
c.
the substrate
d.
a coenzyme

Answer

C. the substrate

8-5 §8.MC source ↗

Which of the following are organic molecules that help enzymes work correctly?

a.
cofactors
b.
coenzymes
c.
holoenzymes
d.
apoenzymes

Answer

B. coenzymes

8-6 §8.MC source ↗

During which of the following is ATP not made by substrate-level phosphorylation?

a.
Embden-Meyerhof pathway
b.
Transition reaction
c.
Krebs cycle
d.
Entner-Doudoroff pathway

Answer

B. Transition reaction

8-7 §8.MC source ↗

Which of the following products is made during Embden-Meyerhof glycolysis?

a.
NAD+
b.
pyruvate
c.
CO₂
d.
two-carbon acetyl

Answer

B. pyruvate

8-8 §8.MC source ↗

During the catabolism of glucose, which of the following is produced only in the Krebs cycle?

a.
ATP
b.
NADH
c.
NADPH
d.
FADH₂

Answer

D. FADH₂

8-9 §8.MC source ↗

Which of the following is not a name for the cycle resulting in the conversion of a two-carbon acetyl to one ATP, two CO₂, one FADH₂, and three NADH molecules?

a.
Krebs cycle
b.
tricarboxylic acid cycle
c.
Calvin cycle
d.
citric acid cycle

Answer

C. Calvin cycle

8-10 §8.MC source ↗

Which is the location of electron transports systems in prokaryotes?

a.
the outer mitochondrial membrane
b.
the cytoplasm
c.
the inner mitochondrial membrane
d.
the cytoplasmic membrane

Answer

D. the cytoplasmic membrane

8-11 §8.MC source ↗

Which is the source of the energy used to make ATP by oxidative phosphorylation?

a.
oxygen
b.
high-energy phosphate bonds
c.
the proton motive force
d.
P_i

Answer

C. the proton motive force

8-12 §8.MC source ↗

A cell might perform anaerobic respiration for which of the following reasons?

a.
It lacks glucose for degradation.
b.
It lacks the transition reaction to convert pyruvate to acetyl-CoA.
c.
It lacks Krebs cycle enzymes for processing acetyl-CoA to CO₂.
d.
It lacks a cytochrome oxidase for passing electrons to oxygen.

Answer

D. It lacks a cytochrome oxidase for passing electrons to oxygen.

8-13 §8.MC source ↗

In prokaryotes, which of the following is true?

a.
As electrons are transferred through an ETS, H⁺ is pumped out of the cell.
b.
As electrons are transferred through an ETS, H⁺ is pumped into the cell.
c.
As protons are transferred through an ETS, electrons are pumped out of the cell.
d.
As protons are transferred through an ETS, electrons are pumped into the cell.

Answer

A. As electrons are transferred through an ETS, H⁺ is pumped out of the cell.

8-14 §8.MC source ↗

Which of the following is not an electron carrier within an electron transport system?

a.
flavoprotein
b.
ATP synthase
c.
ubiquinone
d.
cytochrome oxidase

Answer

B. ATP synthase

8-15 §8.MC source ↗

Which of the following is the purpose of fermentation?

a.
to make ATP
b.
to make carbon molecule intermediates for anabolism
c.
to make NADH
d.
to make NAD⁺

Answer

D. to make NAD⁺

8-16 §8.MC source ↗

Which molecule typically serves as the final electron acceptor during fermentation?

a.
oxygen
b.
NAD⁺
c.
pyruvate
d.
CO₂

Answer

C. pyruvate

8-17 §8.MC source ↗

Which fermentation product is important for making bread rise?

a.
ethanol
b.
CO₂
c.
lactic acid
d.
hydrogen gas

Answer

B. CO₂

8-18 §8.MC source ↗

Which of the following is not a commercially important fermentation product?

a.
ethanol
b.
pyruvate
c.
butanol
d.
penicillin

Answer

B. pyruvate

8-19 §8.MC source ↗

Which of the following molecules is not produced during the breakdown of phospholipids?

a.
glucose
b.
glycerol
c.
acetyl groups
d.
fatty acids

Answer

A. glucose

8-20 §8.MC source ↗

Caseinase is which type of enzyme?

a.
phospholipase
b.
lipase
c.
extracellular protease
d.
intracellular protease

Answer

C. extracellular protease

8-21 §8.MC source ↗

Which of the following is the first step in triglyceride degradation?

a.
removal of fatty acids
b.
β-oxidation
c.
breakage of fused rings
d.
formation of smaller peptides

Answer

A. removal of fatty acids

8-22 §8.MC source ↗

During the light-dependent reactions, which molecule loses an electron?

a.
a light-harvesting pigment molecule
b.
a reaction center pigment molecule
c.
NADPH
d.
3-phosphoglycerate

Answer

B. a reaction center pigment molecule

8-23 §8.MC source ↗

In prokaryotes, in which direction are hydrogen ions pumped by the electron transport system of photosynthetic membranes?

a.
to the outside of the plasma membrane
b.
to the inside (cytoplasm) of the cell
c.
to the stroma
d.
to the intermembrane space of the chloroplast

Answer

A. to the outside of the plasma membrane

8-24 §8.MC source ↗

Which of the following does not occur during cyclic photophosphorylation in cyanobacteria?

a.
electron transport through an ETS
b.
photosystem I use
c.
ATP synthesis
d.
NADPH formation

Answer

D. NADPH formation

8-25 §8.MC source ↗

Which of the following are two products of the light-dependent reactions?

a.
glucose and NADPH
b.
NADPH and ATP
c.
glyceraldehyde 3-phosphate and CO₂
d.
glucose and oxygen

Answer

B. NADPH and ATP

8-26 §8.MC source ↗

Which of the following is the group of archaea that can use CO₂ as their final electron acceptor during anaerobic respiration, producing CH₄?

a.
methylotrophs
b.
methanotrophs
c.
methanogens
d.
anoxygenic photosynthesizers

Answer

C. methanogens

8-27 §8.MC source ↗

Which of the following processes is not involved in the conversion of organic nitrogen to nitrogen gas?

a.
nitrogen fixation
b.
ammonification
c.
nitrification
d.
denitrification

Answer

A. nitrogen fixation

8-28 §8.MC source ↗

Which of the following processes produces hydrogen sulfide?

a.
anoxygenic photosynthesis
b.
oxygenic photosynthesis
c.
anaerobic respiration
d.
chemoautrophy

Answer

C. anaerobic respiration

8-29 §8.MC source ↗

The biogeochemical cycle of which of the following elements is based on changes in solubility rather than redox chemistry?

a.
carbon
b.
sulfur
c.
nitrogen
d.
phosphorus

Answer

D. phosphorus

8-36 §8.FITB source ↗

Processes in which cellular energy is used to make complex molecules from simpler ones are described as ________.

Answer

anabolic

8-37 §8.FITB source ↗

The loss of an electron from a molecule is called ________.

Answer

oxidation

8-38 §8.FITB source ↗

The part of an enzyme to which a substrate binds is called the ________.

Answer

active site

8-39 §8.FITB source ↗

Per turn of the Krebs cycle, one acetyl is oxidized, forming ____ CO₂, ____ ATP, ____ NADH, and ____ FADH₂ molecules.

Answer

2; 1; 3; 1

8-40 §8.FITB source ↗

Most commonly, glycolysis occurs by the ________ pathway.

Answer

Embden-Meyerhof

8-41 §8.FITB source ↗

The final ETS complex used in aerobic respiration that transfers energy-depleted electrons to oxygen to form H₂O is called ________.

Answer

cytochrome oxidase

8-42 §8.FITB source ↗

The passage of hydrogen ions through ________ down their electrochemical gradient harnesses the energy needed for ATP synthesis by oxidative phosphorylation.

Answer

ATP synthase

8-43 §8.FITB source ↗

The microbe responsible for ethanol fermentation for the purpose of producing alcoholic beverages is ________.

Answer

yeast (Saccharomyces cerevisiae)

8-44 §8.FITB source ↗

________ results in the production of a mixture of fermentation products, including lactic acid, ethanol and/or acetic acid, and CO₂.

Answer

Heterolactic fermentation

8-45 §8.FITB source ↗

Fermenting organisms make ATP through the process of ________.

Answer

glycolysis

8-46 §8.FITB source ↗

The process by which two-carbon units are sequentially removed from fatty acids, producing acetyl-CoA, FADH₂, and NADH is called ________.

Answer

β-oxidation

8-47 §8.FITB source ↗

The NADH and FADH₂ produced during β-oxidation are used to make ________.

Answer

ATP by oxidative phosphorylation

8-48 §8.FITB source ↗

________ is a type of medium used to detect the production of an extracellular protease called caseinase.

Answer

Skim milk agar

8-49 §8.FITB source ↗

The enzyme responsible for CO₂ fixation during the Calvin cycle is called ________.

Answer

ribulose bisphosphate carboxylase (RuBisCO)

8-50 §8.FITB source ↗

The types of pigment molecules found in plants, algae, and cyanobacteria are ________ and ________.

Answer

chlorophylls and carotenoids

8-51 §8.FITB source ↗

The molecule central to the carbon cycle that is exchanged within and between ecosystems, being produced by heterotrophs and used by autotrophs, is ________.

Answer

carbon dioxide

8-52 §8.FITB source ↗

The use of microbes to remove pollutants from a contaminated system is called ________.

Answer

bioremediation

8-30 §8.TF source ↗

Competitive inhibitors bind to allosteric sites.

Answer

False

8-31 §8.TF source ↗

Glycolysis requires oxygen or another inorganic final electron acceptor to proceed.

Answer

False

8-32 §8.TF source ↗

All organisms that use aerobic cellular respiration have cytochrome oxidase.

Answer

True

8-33 §8.TF source ↗

Photosynthesis always results in the formation of oxygen.

Answer

False

8-34 §8.TF source ↗

There are many naturally occurring microbes that have the ability to degrade several of the compounds found in oil.

Answer

True

8-35 §8.M source ↗

Match the fermentation pathway with the correct commercial product it is used to produce:

___acetone-butanol-ethanol fermentation	a. bread
___alcohol fermentation	b. pharmaceuticals
___lactic acid fermentation	c. Swiss cheese
___mixed acid fermentation	d. yogurt
___propionic acid fermentation	e. industrial solvents

Answer

1. e; 2. a; 3. d; 4. b; 5. c

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Problems and answers are adapted from Microbiology by Nina Parker, Mark Schneegurt, Anh-Hue Thi Tu, Philip Lister and Brian M. Forster, OpenStax, and are used under the CC BY-NC-SA 4.0 licence. Access for free at https://openstax.org/books/microbiology/pages/1-introduction. Illustrations: Copyright Rice University, OpenStax, under CC BY-NC-SA 4.0 license. This adaptation is released under the same licence, is non-commercial, and is neither affiliated with nor endorsed by OpenStax or Rice University.