EXAM 2: Chapter 7

In the absence of oxygen, cells need a way to regenerate which compound following glycolysis?

NAD+

When a poison such as cyanide blocks the electron transport chain, glycolysis and the citric acid cycle also eventually stop working. Which of the following is the best explanation for this?

NAD+ and FAD are not available for glycolysis and the citric acid cycle to continue.

Which of the following substances is/are involved in oxidative phosphorylation?

All of the listed substances are involved in oxidative phosphorylation.

In the overall process of glycolysis and cellular respiration, __________ is oxidized and __________ is reduced.

glucose; oxygen

Which of the following best describes the electron transport chain of cellular respiration?

Electrons are passed from one carrier to another, releasing a little energy at each step.

How many molecules of ATP are gained by substrate-level phosphorylation from the complete breakdown of a single molecule of glucose in the presence of oxygen?

Four

Of the metabolic pathways listed below, which is the most universal metabolic process associated with cellular respiration?

Glycolysis

The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the __________.

H+ concentration across the membrane holding ATP synthase

Where do the reactions of glycolysis occur in a eukaryotic cell?

In the cytosol

Molecular oxygen (O2) has what role in aerobic cellular respiration?

It is the final electron acceptor at the end of the electron transport chain.

After completion of the citric acid cycle, most of the usable energy from the original glucose molecule is in the form of __________.

NADH

Which process is the one in which glucose is oxidized to generate two molecules of pyruvate and in which ATP and NADH are produced?

None of the listed responses is correct.

Which of the following is a correct description and sequence of events in cellular respiration?

Oxidation of glucose to pyruvate; oxidation of pyruvate; oxidation of acetyl-coA; oxidative phosphorylation

Most of the ATP produced in aerobic cellular respiration comes from which of the following processes?

Oxidative phosphorylation

During the reaction C6H12O6 + 6 O2 → 6 CO2 + 6 H2O, which compound is reduced as a result of the reaction?

Oxygen

Most of the NADH that delivers electrons to the electron transport chain comes from which of the following processes?

The citric acid cycle

Why is the citric acid cycle called a cycle?

The four-carbon acid that accepts the acetyl CoA in the first step of the cycle is regenerated by the last step of the pathway.

Where do the reactions of the citric acid cycle occur in eukaryotic cells?

The matrix of the mitochondrion

In an experiment, mice were fed glucose (C6H12O6) containing a small amount of radioactive oxygen. The mice were closely monitored, and after a few minutes radioactive oxygen atoms showed up in __________.

carbon dioxide

Of the following molecules in the glycolytic pathway (the process of glycolysis), the one with the most chemical energy is __________.

fructose-1,6-bisphosphate

The electron transport chain involved in cellular respiration is located in/on the __________.

inner membrane of the mitochondrion

A molecule becomes oxidized when it __________.

loses an electron