Mastering Microbiology Ch 05 HW

Which of the following statements concerning cellular metabolism is FALSE?

Macromolecules are converted into cell structures via catabolism.

Which type of chemical reactions in cells release energy?

Metabolic

Which of the following can be used as a final electron acceptor for aerobic respiration?

Molecular oxygen

Glycolysis produces energy in which form?

NADH and ATP

According to the animation, which compounds provide electrons to the system?

NADH and FADH2

What role do NADH and FADH2 serve in catabolism?

NADH and FADH2 are electron carriers.

Where is the majority of ATP generated in prokaryotic cells?

in the cytoplasmic membrane

How many ATP molecules can theoretically be produced from the NADH generated by the catabolism of a molecule of glucose during aerobic respiration?

30

What is the function of GTP?

An energy carrier

What occurs at the bridge step?

Decarboxylation of pyruvic acid

Why does FADH2 yield less ATP than NADH?

FADH2 electrons enter the electron transport chain at a lower energy level.

Based on the animation, how many electron carriers are reduced in the Krebs cycle only?

Four

Which step is the step for which glycolysis is named?

Fourth

Which of the following statements concerning glycolysis is TRUE?

Glucose is activated by substrate-level phosphorylation.

Which of the following statements about glycolysis is true?

Glycolysis is also called the Embden-Meyerhof pathway.

Where would you expect to find electron transport chains in a prokaryote?

Along the plasma membrane

Why is ATP required for glycolysis?

ATP makes it easier to break apart glucose into two three-carbon molecules.

What is the intermediate product formed by pyruvic acid during alcoholic fermentation?

Acetaldehyde

Where does the energy required for anabolic reactions come from?

Catabolic reactions

What is the defining characteristic of a redox reaction?

Electrons are transferred from an electron donor to an electron acceptor.

Which of the following statements about fermentation is true?

It is an alternative way to return electron carriers to their oxidized state.

What is the fate of the NAD+ newly regenerated by fermentation?

It returns to glycolysis to pick up more electrons.

What is the role of pyruvic acid in fermentation?

It takes the electrons from NADH, oxidizing it back into NAD+.

Which of the following pathways produces the most NADH and the least ATP?

Krebs cycle

Iron is considered an essential element for many bacteria. Based on the animation, how would lack of iron affect energy production of a bacterium?

Lack of iron would mean lack of heme, and thus lower amounts of functioning cytochrome proteins. This would mean lower energy yields.

Which of the following is an acid produced by fermentation?

Lactic acid and propionic acid

Which of the following is needed as a reactant for the first step of the citric acid cycle?

Oxaloacetic acid

What is meant by substrate-level phosphorylation?

Production of ATP by transferring phosphates directly from metabolic products to ADP

How does the proton gradient help ATP synthase to make ATP?

Protons move from outside the membrane to inside the membrane.

What molecule carries carbon atoms from glycolysis into the citric acid cycle?

Pyruvate

What carbon molecules remain at the end of glycolysis?

Pyruvic acid

Which of the following statements regarding redox reactions is true?

Redox reactions involve an oxidation reaction coupled with a reduction reaction.

Where does the energy come from to power the formation of GTP?

Succinyl CoA

According to the animation, what does the electron transport chain do to the concentration of hydrogen ions (protons)?

The concentration of protons is higher outside the membrane than inside.

Why is reduction the term used to describe the gain of an electron?

The electron acceptor's net charge decreases.

Which of the following statements concerning glycolysis is TRUE?

The glycolytic pathway has a net gain of two ATP molecules.

What is the driving force of energy production in steps 6 and 7?

The oxidation of three-carbon compounds

Which step(s) of the Krebs cycle does (do) not produce any usable energy?

The second and seventh steps

Which step involves the release of carbon dioxide?

The third and fourth steps

What is the fate of metabolites during respiration?

They are oxidized completely to carbon dioxide and water.

How many molecules of ATP can be generated from one molecule of NADH?

Three

How many net ATPs can be made from one molecule of glucose in glycolysis?

Two

What is the net production of ATP in glycolysis?

Two ATP

What is one difference between ubiquinones and cytochromes?

Ubiquinones are not made of protein; cytochromes are.

According to the animation, what does oxygen get reduced to at the end of the electron transport chain?

Water

A reaction that involves the transfer of electrons from one molecule to another is referred to as

a redox reaction.

Which of the following is a by-product of the catabolism of proteins?

ammonia

The reactions involved in producing larger compounds from smaller compounds is called

anabolism.

Fatty acids are catabolized into two carbon molecules during the process of __________.

beta-oxidation

Anaerobic bacteria may use ________ as the final electron acceptor during anaerobic respiration.

both nitrate and sulfate

The process of generating ATP using a proton gradient is referred to as

chemiosmosis.

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

decarboxylation

Oxidative phosphorylation of ATP occurs during

electron transport.

Which of the following is an INCORRECT association?

electron transport: acetyl-CoA

Although glycolysis requires an input of ATP, this pathway results in a net gain of two ATP; therefore it is a(n) ________ pathway.

exergonic

Catabolism of glucose begins with

glycolysis

Pyruvic acid is a product of

glycolysis.

The use of amino acids to make proteins

is an example of anabolism.

In metabolism, energy that is not used

is given off as heat.

The electron transport chain provides the energy for

oxidative phosphorylation.

Which of the following is NOT an electron acceptor in anaerobic respiration?

oxygen

Any molecule that serves as an electron acceptor will be __________.

reduced

During carbohydrate catabolism, more ATP molecules are produced during

substrate-level phosphorylation.

Glycolysis literally means

sugar splitting.

During an oxidation reaction,

the donor molecule loses an electron and becomes oxidized.