Deck 5: Microbial Metabolism

Question 1

What is the purpose of the light- dependent reactions of photosynthesis?

A) production of ATP and NADPH
B) production of ATP and NADH
C) regeneration of NAD+
D) carbon fixation
E) production of oxygen

Answer 1

A

Question 2

Types of chlorophyll differ in

A) the amount of oxygen they use up.
B) the number of electrons they release.
C) the amount of light they can absorb.
D) the wavelengths of light they absorb.
E) the amount of ATP they produce.

Answer 2

D

Question 3

All of the following are true statements concerning glycolysis EXCEPT:

A) It involves the conversion of a molecule of glucose into a molecule of pyruvic acid.
B) It produces ATP by substrate- level phosphorylation.
C) It uses, as well as produces, ATP.
D) It is a pathway common to both respiration and fermentation.
E) It occurs in the cytoplasm of the cell.

Answer 3

A

Question 4

How many ATP molecules are produced from the NADH generated by the catabolism of a molecule of glucose?

A) 4
B) 36
C) 34
D) 30
E) 38

Question 5

All of the following are associated with chemiosmosis EXCEPT:

A) phosphorylation of 34 molecules of ADP.
B) oxidative phosphorylation.
C) creation of a proton gradient.
D) beta- oxidation.
E) ATP synthase.

Question 6

All of the following are characteristics of catabolic pathways EXCEPT:

A) they produce ATP.
B) they break large molecules into smaller ones.
C) they are exergonic.
D) Both A and C are correct.
E) A, B, and C are correct.

Question 7

All of the following are true statements concerning cellular metabolism EXCEPT:

A) ATP is used in the formation of macromolecules.
B) Macromolecules are converted into cell structures via catabolism.
C) Energy obtained from nutrients or light is stored in the bonds of ATP.
D) Enzymes are used in both catabolic and anabolic reactions.
E) The goal of metabolism is reproduction of the organism.

Question 8

All of the following are true statements concerning enzymes EXCEPT:

A) They form a temporary intermediate compound with a substrate.
B) They can be used to catalyze a chemical reaction over and over again.
C) They function best at 37°C.
D) They are usually, but not always, proteins.
E) They can be denatured if the pH of their environment is too high or too low.

Question 9

All of the following are by- products of various types of anaerobic respiration in bacteria EXCEPT:

A) nitrite ions.
B) nitrous oxide.
C) methane.
D) carbonate.
E) hydrogen sulfide.

Question 10

All of the following are forms of oxidation EXCEPT:

A) loss of hydrogen atom.
B) gaining an oxygen atom and its electrons.
C) substrate- level phosphorylation.
D) loss of an electron.
E) a dehydrogenation event.

Question 11

Which of the following is a lipid- soluble molecule found in electron transport chains?

A) thylakoids
B) ubiquinones
C) metal- containing proteins
D) flavoproteins
E) cytochromes

Question 12

Which of the following does NOT happen during the Krebs cycle?

A) NADH is oxidized.
B) Oxaloacetic acid is regenerated.
C) Substrate- level phosphorylation occurs.
D) GTP is produced.
E) Two molecules of CO2 are given off.

Question 13

Sulfanilamide is an antimicrobial drug that mimics the shape of an important substrate for a particular bacterial enzyme, thereby inhibiting the enzyme. This type of inhibition is known as

A) competitive inhibition.
B) excitatory allosteric control.
C) allosteric inhibition.
D) Both A and C are correct.
E) A, B, and C are correct.

Question 14

Which of the following is a common feature of chemiosmosis and the light- dependent reactions of photosynthesis?

A) reduction of NADP+
B) electron transport
C) a proton gradient
D) Both B and C are correct.
E) A, B, and C are correct.

Question 15

The synthesis of acetyl- CoA from pyruvic acid serves as a bridge between glycolysis and which of the following processes?

A) the Entner- Doudoroff pathway
B) chemiosmosis
C) the Calvin- Benson cycle
D) fermentation
E) the Krebs cycle

Question 16

Carbon dioxide is a by- product of which of the following?

A) chemiosmosis
B) electron transport
C) the pentose phosphate pathway
D) the Krebs cycle
E) glycolysis

Question 17

NADPH is associated with which of the following?

A) beta- oxidation
B) the Embden- Meyerhof pathway
C) glycolysis
D) gluconeogenesis
E) the pentose phosphate pathway

Question 18

All of the following are true statements concerning reduction reactions EXCEPT:

A) An electron acceptor becomes more positively charged.
B) They frequently involve electron carrier molecules.
C) An electron acceptor gains an electron.
D) They are coupled with oxidation reactions.
E) A molecule gains a hydrogen atom.

Question 19

Ammonia is a by- product of the catabolism of which of the following?

A) fatty acids
B) proteins
C) polysaccharides
D) lipids
E) nucleic acids

Question 20

A substrate is

A) an inorganic cofactor for an enzyme.
B) a chemical that increases the likelihood of a particular reaction.
C) an enzyme that has lost its three- dimensional structure.
D) an enzyme made out of RNA.
E) the molecule upon which a particular enzyme acts.

Question 21

Membranes containing the photosystems necessary for photosynthesis are called

A) grana.
B) cytochromes.
C) thylakoids.
D) chlorophylls.
E) stroma.

Question 22

Increasing substrate concentration will increase the activity of an enzyme, up to a point.

Question 23

Folic acid is necessary for the biosynthesis of which of the following?

A) acetyl- CoA
B) nucleotides
C) amino acids
D) glyceraldehyde 3- phosphate
E) fatty acids

Question 24

All of the following are true statements regarding fermentation EXCEPT:

A) It starts with glycolysis.
B) NADH is oxidized.
C) The final electron acceptor is an organic molecule.
D) Ethanol and lactic acid are possible substrates.
E) The main goal is the regeneration of NAD+.

Question 25

Which of the following is a true statement concerning the structure and function of enzymes?

A) An apoenzyme is a combination of a cofactor bound to a holoenzyme.
B) After an enzyme has catalyzed a reaction, it resumes its original shape and can interact with a new substrate molecule.
C) The higher the temperature, the faster an enzyme will work.
D) Competitive inhibition of an enzyme occurs when an inhibitor binds to an allosteric site on the enzyme.
E) All enzymes bind to cofactors necessary for their function.

Question 26

When a cell forms an amino acid by adding an amine group derived from ammonia to a precursor metabolite, this process is called

A) polymerization.
B) deamination.
C) reduction.
D) amination.
E) transamination.

Question 27

In which of the following stages of glycolysis is ATP made?

A) lysis stage
B) energy- investment stage
C) energy- conserving stage
D) Both B and C are correct.
E) Both A and B are correct.

Question 28

Ribozymes are enzymes that cleave the subunits of the ribosome.

Question 29

All of the following are characteristics of noncyclic photophosphorylation EXCEPT:

A) both ATP and NADPH are generated.
B) it requires both photosystem I and II.
C) electrons are obtained from molecules such as water.
D) it occurs in all plants and algae.
E) electrons return to the photosystem that generated them.

Question 30

Which of the following occurs during cellular respiration?

A) substrate- level phosphorylation
B) oxidative phosphorylation
C) photophosphorylation
D) Both A and B are correct.
E) A, B, and C are correct.

Question 31

Chemical reactions that can proceed toward either anabolism or catabolism are called

A) amphibolic.
B) cyclic.
C) synthetic.
D) light- independent.
E) glycolytic.

Question 32

The denaturation of an enzyme is always irreversible.

Question 33

Where is the most ATP generated for eukaryotic cells?

A) in the outer membrane of the mitochondria
B) on ribosomes
C) in the cytosol
D) in the mitochondrial matrix
E) in the cytoplasmic membrane

Question 34

The conversion of pyruvic acid to acetyl- CoA can be described as _ , since a molecule of CO2 is produced as a by- product.

A) respiration
B) phosphorylation
C) amination
D) decarboxylation
E) oxidation

Question 35

Amphibolic reactions are neither catabolic nor anabolic.

Question 36

NAD+ and NADP+ are important examples of both coenzymes and electron carriers.

Question 37

What is the major product of the Calvin- Benson cycle that can then be used to form glucose?

A) ATP
B) CO2
C) NADPH
D) RuBP
E) glyceraldehyde 3- phosphate

Question 38

All of the following are aspects of a cell's ability to regulate its metabolism EXCEPT:

A) isolation of various enzymes within membranous organelles.
B) synthesis of a catabolic enzyme only when its substrate is available.
C) using the same coenzymes for anabolic and catabolic reactions that share substrate molecules.
D) synthesis or degradation of membrane transport proteins.
E) using the most energy- efficient energy source available.

Question 39

RuBP is associated with which of the following?

A) chemiosmosis
B) the tricarboxylic acid cycle
C) the Embden- Meyerhof pathway
D) the Calvin- Benson cycle
E) the Entner- Doudoroff pathway

Question 40

If a cell reverses the process of beta- oxidation, which of the following molecules will it be making?

A) starch
B) nucleotides
C) amino acids
D) fatty acids
E) glycerol

Question 41

Fermentation pathways provide a cell with an alternative way to regenerate NAD+ for glycolysis.

Question 42

Anaerobic respiration involves the use of molecules other than as the final electron acceptor in an electron transport chain.

Question 43

A(n) is a collection of pigments such as chlorophyll that are used to absorb light in the light- dependent reactions of photosynthesis.

Question 44

The excited electrons that begin the light- dependent reactions of photosynthesis come from a special molecule called the chlorophyll.

Question 45

The of an enzyme is reached when all active sites have bound substrate molecules.

Question 46

The process of using light energy to attach inorganic phosphate to ADP molecules is called .

Question 47

Laboratory fermentation tests often include a pH indicator because many bacteria produce as they ferment carbohydrates.

Question 48

During chemiosmosis, electrons are pumped across a membrane in order to produce ATP.

Question 49

Enzymes increase the rate of reaction by lowering the .

Question 50

Transamination involves the transfer of an amine group from an amino acid to a metabolite, converting the metabolite into a new amino acid.

Question 51

When an inhibitor molecule binds to a(n) on an enzyme, the shape of the active site changes so that substrate molecules can no longer bind.

Question 52

The purpose of electron transport is to create a(n) _ _ across a membrane that can then be used to make ATP.

Question 53

The is a pathway in which the energy in acetyl- CoA molecules is converted to the form of NADH and FADH2.

Question 54

photosynthetic bacteria produce waste products such as sulfur as they obtain electrons for noncyclic photophosphorylation.

Question 55

Another term for an organic catalyst is a(n) .

Question 56

are enzymes used in the catabolism of fats.

Question 57

Essential amino acids are those that cannot be synthesized by an organism and so must be provided as a nutrient.

Question 58

Proteins are used as energy sources only when carbohydrates and lipids are not available.

Question 59

are enzymes that simply rearrange the atoms within a molecule.

Question 60

During electron transport in chloroplast thylakoids, protons are pumped outside the thylakoid into a space called the _.

Question 61

Explain why fermentation is a necessary alternative to respiration in many cells.

Question 62

Explain why the ATP yield from processes such as cellular respiration is generally given as a theoretical number.

Question 63

Compare and contrast cyclic and noncyclic photophosphorylation.

Question 64

Describe the mechanism of feedback inhibition and the role this process plays in controlling enzyme activity.

Question 65

Explain how cells use and regulate their enzymes as a way to control their metabolism.