Bio 6

In preparing pyruvate to enter the citric acid cycle, which of the following steps occurs?

A compound called coenzyme A binds to a two-carbon fragment.

Sports physiologists at an Olympic training center want to monitor athletes to determine at what point their muscles begin to function anaerobically. They could do this by checking for a buildup of _____.

lactic acid

The electron transport chain is a series of electron carrier molecules. In eukaryotes, where can this structure be fo

mitochondria

A scientist wants to study the enzymes of the citric acid cycle in eukaryotic cells. What part of the cell would she use as a source of these enzymes?

mitochondrial matrix

Cellular respiration completely breaks down a glucose molecule through glycolysis and the citric acid cycle. However, these two processes yield only a few ATPs. The majority of the energy the cell derives from glucose is _____.

found in NADH and FADH2

Each turn of the citric acid cycle generates one ATP and ___ additional energy-rich molecules: __________.

four; 3 NADH and 1 FADH2

The energy production per acetyl CoA molecule through the citric acid cycle is __________.

1 ATP, 3 NADH, 1 FADH2

Substrate-level phosphorylation directly generates ATP during a chemical reaction. As a single molecule of glucose is completely oxidized in the presence of oxygen, what is the net yield of molecules of ATP made by substrate-level phosphorylation?

4 ATP

Why is the citric acid cycle called a cycle?

Acetyl CoA binds to oxaloacetate and this compound is restored at the end of the cycle.

Which of the following statements regarding aerobic cellular respiration is TRUE?

Glucose is completely oxidized to form carbon dioxide.

What happens to the energy that is released by electrons as they move through the electron transport chain?

It pumps H+ through a membrane.

During fermentation, __________ that was produced during glycolysis is converted back to __________.

NADH; NAD+

Using the ATP generated during cellular respiration, the intermediates of glycolysis and the citric acid cycle, such as pyruvate and acetyl CoA, can be siphoned off and used to __________.

build amino acids, fats, and sugars

Which of the following is the source of the energy that produces the chemiosmotic gradient in mitochondria?

electrons

Some human cells, such as nerve cells, are restricted to aerobic respiration to recycle NADH and FADH2. If these cells are deprived of oxygen, then __________.

oxidative phosphorylation would come to a halt because there wouldn't be any oxygen to "pull" the electrons down the transport chain

Bacteria have no membrane-enclosed organelles. However, some still generate ATP through cellular respiration. Where might the electron transport chain be found in these organisms?

plasma membrane

In oxidative phosphorylation, electrons are passed from one electron carrier to another. The energy released is used to __________.

pump protons (H+) across the mitochondrial membrane

A muscle cell deprived of molecular oxygen will convert glucose to lactic acid to __________.

recycle NADH through fermentation

Most NADH molecules generated during cellular respiration are produced during __________.

the citric acid cycle

The enzyme ATP synthase catalyzes the phosphorylation of ADP to form ATP. In eukaryotic cells, the energy needed for this endergonic reaction is directly derived from __________.

the movement of hydrogen ions across the mitochondrial membrane