Chapter 7 Launchpad

Which of the following statements is true regarding pyruvate oxidation?

Pyruvate oxidation forms the same number of NADH (per glucose molecule) as glycolysis.

The proteins of the electron transport chain are:

embedded in the inner mitochondrial membrane.

The citric acid cycle is a cycle because the starting molecule, _____, is regenerated at the end.

oxaloacetate

Which of the following does not occur during the third phase of glycolysis?

oxygen consumption

We can tell from their structure that fatty acids are a good source of energy because of:

the large number of carbon-carbon and carbon-hydrogen bonds they contain.

At the end of glycolysis, the carbon molecules originally found in the starting glucose molecule are in the form of:

two pyruvate molecules.

When a single pyruvate is converted to acetyl-CoA, the other products of the reaction are:

NADH and CO2.

Which of the following statements is true regarding aerobic respiration?

None of the above.

Which of the following statements is true regarding the equation C6H12O6 + 6O2 →6CO2+ 6H2O + energy?

The oxygen atoms in both CO2 and H2O are electronegative, and glucose is considered a reducing agent.

T/F The ATP produced during glycolysis is the result of substrate-level phosphorylation.

True

In cellular respiration, oxygen:

gains electrons and is an oxidizing agent.

How did the earliest organisms on Earth most likely produce ATP?

glycolysis

An electron from NADH entering the electron transport chain would travel among components of the chain in what sequence?

complex I, coenzyme Q, complex III, cytochrome C, complex IV, oxygen

Phosphorylating glucose during phase 1 of glycolysis:

destabilizes the glucose molecule so that it can be broken down in phase 2.

During what phase of glycolysis is NADH formed?

during phase 3, when glyceraldehyde 3-phosphate is phosphorylated

The inputs to glycolysis do not include:

NADH

Once they have been processed through the citric acid cycle, the acetyl-CoA molecules from a single glucose molecule produce:

2 ATP, 6 NADH, 4 CO2

After pyruvate oxidation, the chemical energy of how many carbons of the original glucose molecule is converted to chemical energy in the form of ATP in the remaining steps of cellular respiration?

4

Which best describes energy production during cellular respiration?

A small amount of energy is produced by substrate-level phosphorylation; most is produced by oxidative phosphorylation.

Beta-oxidation of fatty acids does not directly produce:

ATP

Which of the following statements are true regarding pyruvate oxidation?

All of these choices are correct. This process occurs within the matrix of mitochondria. This process constitutes the second stage of cellular respiration. The process produces both CO2 and acetyl-CoA. The process yields no ATP via substrate-level phosphorylation.

Lactic acid fermentation occurs in: Select all that apply. plants and bacteria. bacteria and animals. animals and plants. animals and fungi. fungi and bacteria.

Bacteria and animals

T/F By the time pyruvate is formed, most of the energy contained in glucose has been released.

False

T/F Oxidation is the gain of electrons

False

T/F Pyruvate oxidation is remarkably similar to glycolysis in that when one molecule of pyruvate enters into a mitochondrion, two molecules of acetyl-CoA are formed.

False

T/F The majority of cells within the human body have a very high baseline amount of ATP, so cells are always prepared for any long-term activity.

False

Imagine that a eukaryotic cell carries a mutation impairing its ability to phosphorylate glucose during glycolysis. What is a likely result of this mutation?

Glucose could move out of the cell, slowing cellular respiration.

Some present-day bacteria use a system of anaerobic respiration characterized by an electron transport chain analogous to that found in aerobic organisms. Which of the following correctly characterizes the anaerobic electron transport chain?

It establishes a proton gradient between the cytoplasm and the extracellular fluid.

We consume a variety of carbohydrates that are digested into a variety of different sugars. How do these different sugars enter glycolysis?

Sugars are converted to various forms and enter glycolysis at various stages.

Glycolysis is:

anaerobic

Pyruvate oxidation is an important stage in cellular respiration because:

it links glycolysis with the citric acid cycle.

The chemical bonds of carbohydrates and lipids have high potential energy because:

many of these bonds are C—C and C—H bonds.

In eukaryotes, pyruvate oxidation takes place in the:

mitochondrial matrix.

Which of the following is not an end product for an acetyl group that enters the citric acid cycle?

oxaloacetate

In cellular respiration, glucose is _____ to CO2 and oxygen is _____ to water.

oxidized; reduced

In the second phase of glycolysis:

phosphorylated sugar molecule is cleaved and the products rearranged.

Which of the following correctly characterizes the F1 subunit of ATP synthase?

the catalytic unit that synthesizes ATP

Which of the following processes produces the highest number of reduced electron carriers and thus the greatest amount of ATP by oxidative phosphorylation?

the citric acid cycle

During fermentation, pyruvate is:

reduced

If you've ever learned about beer making, you may know that some people add fruit juice to their yeast mixtures. Why?

to provide glucose to the yeast

Coenzyme Q and cytochrome c:

transfer electrons between protein complexes of the electron transport chain.