In alcohol fermentation, NAD+ is regenerated from NADH during which of the following?

reduction of acetaldehyde to ethanol (ethyl alcohol)

The direct products from the citric acid cycle are ________.

NOT final products of cellular respiration (work in progress)

Starting with citrate, which of the following combinations of products would result from three turns of the citric acid cycle?

3 ATP, 6 CO2, 9 NADH, and 3 FADH2

Chemiosmosis involves ________.

the movement of hydrogen ions across a membrane

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

the H+ concentration gradient across the inner mitochondrial membrane.

What is the major physiological importance of breathing?

Oxygen must be present in our cells to break down food into energy.

Which of the following is a true distinction between fermentation and cellular respiration?

NADH is oxidized by the electron transport chain in respiration only.

Where are the enzymes of glycolysis located within the cell?

cytosol

Which kind of metabolic poison would most directly interfere with glycolysis?

an agent that closely mimics the structure of glucose but is not metabolized

What is the net energy yield for the anaerobic metabolism of one glucose molecule?

NOT two molecules of ATP and three NADH (work in progress)

In the absence of oxygen, yeast cells can obtain energy by fermentation, resulting in the production of

ATP, CO2, and ethanol (ethyl alcohol)

Carbon skeletons for amino acid biosynthesis are supplied by intermediates of the citric acid cycle. Which intermediate would supply the carbon skeleton for synthesis of a five-carbon amino acid?

α-ketoglutarate

When a molecule of NAD+ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a hydrogen ion) the molecule becomes

reduced

Where are the proteins of the electron transport chain located?

mitochondrial inner membrane

During aerobic respiration, which of the following directly donates electrons to the electron transport chain at the lowest energy level?

FADH2

What role does O2 play in aerobic respiration?

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

What is the definition of energy?

The capacity to do work

Where does glycolysis occur?

cytosol

Phosphofructokinase is an allosteric enzyme that catalyzes the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate, an early step of glycolysis. In the presence of oxygen, an increase in the amount ATP in a cell would be expected to

inhibit the enzyme and thus slow the rates of glycolysis and the citric acid cycle.

The process of ________ utilizes an organic molecule to regenerate NAD⁺ from NADH.

Fermentation