Chapter 6 Practice Questions: Cellular Respiration

Starting with one molecule of glucose, glycolysis results in the net production of which of the following sets of energy-containing products?

2 NADH, 2 pyruvate, and 2 ATP

Chemiosmosis in mitochondria directly results in the synthesis of:

ATP

The main function of cellular respiration is to produce:

ATP

The enzyme phosphofructokinase (PFK) catalyzes a key step in glycolysis. PFK is inhibited by high levels of which of the following molecules?

ATP and citrate

Which of the listed statements describes the results of the following reaction? C6H12O6+ 6 O2→ 6 CO2+ 6 H2O + Energy -O2 gets oxidized and H2O gets reduced. -O2 gets reduced and CO2 gets oxidized. -CO2 gets reduced and O2 gets oxidized. -C6H12O6 gets oxidized and O2 gets reduced.

C6H12O6 gets oxidized and O2 gets reduced.

During which stage of cellular respiration is the majority of the ATP produced?

Electron transport chain

Which stage of cellular respiration requires oxygen that you breathe?

Electron transport chain

Identify the stage (or stages) of cellular respiration that occurs entirely outside of the mitochondria.

Glycolysis

Which of the following statements best describes the primary role played by oxygen in cellular respiration? -It serves as the final acceptor for electrons from the electron transport chain. -It oxidizes glucose to form two molecules of pyruvate. -It serves as an acceptor for carbon, forming CO2 in the citric acid cycle. -It yields energy in the form of ATP as it is passed down the electron transport chain.

It serves as the final acceptor for electrons from the electron transport chain.

Following glycolysis and the citric acid cycle, but before the electron transport chain and oxidative phosphorylation, the carbon skeleton of glucose has been broken down to CO2 with some net gain of ATP. Most of the energy from the original glucose molecule at that point in the process, however, is stored in the form of which of the following molecules? -pyruvate -acetyl-CoA -NADH -NAD+

NADH

Which electron carrier(s) function in the citric acid cycle?

NADH and FADH2

Alcohol is a waste product produced by yeast in the presence of sugar and the absence of ________.

O2

Alcohol is a waste product produced by yeast in the presence of sugar and the absence of ________.

To oxidize NADH in the absence of O2.

Can energy be harvested by the cells from glucose without oxygen?

Yes, but much less than with oxygen.

In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in the citric acid cycle. First, however, the pyruvate (1) loses a carbon, which is given off as a molecule of CO2, (2) is oxidized to form a two-carbon compound called acetate, and (3) is bonded to coenzyme A. Which of the following sets of products result from these reactions?

acetyl CoA, NADH, and CO2

The synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electrochemical gradient, is an example of which of the following processes?

coupling of an endergonic reaction to an exergonic reaction

In chemiosmosis, what is the most direct source of energy that is used to convert ADP + Pi to ATP?

energy released from movement of protons through ATP synthase, down their electrochemical gradient

The anaerobic breakdown of glucose is called:

fermentation

From the beginning of glycolysis to the end of the Krebs (citric acid) cycle, what has the cell gained from the breakdown of each molecule of glucose?

four molecules of ATP, 10 of NADH, and two of FADH2

In human muscle cells, fermentation (by itself) produces:

lactase

The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction _____.

loses electrons and loses potential energy

Which parts of the mitochondria are directly involved in the synthesis of ATP during chemiosmosis?

matrix and inner membrane

Where are the proteins of the electron transport chain located?

mitochondrial inner membrane

When oxygen is present:

most animal cells utilize aerobic cellular respiration.

Carbon dioxide (CO2) is released during which of the following stages of cellular respiration?

oxidation of pyruvate to acetyl CoA and the citric acid cycle

Which of the following processes generates a proton-motive force in mitochondria? -lowering of pH in the mitochondrial matrix -the flow of protons through ATP synthase down their concentration gradient -the reduction of NAD+ by the first electron carrier in the electron transport chain -pumping of hydrogen ions from the mitochondrial matrix across the inner membrane and into the intermembrane space

pumping of hydrogen ions from the mitochondrial matrix across the inner membrane and into the intermembrane space

The end product of glycolysis is:

two pyruvate molecules