Chapter 7 Homework Answers Part 1

Chemiosmosis can produce between _________ and _________ ATP molecules for every molecule of glucose that is oxidized.

30 & 34

How many ATP molecules are produced by oxidative phosphorylation for every one molecule of glucose that enters the pathways of cellular respiration?

30-34 ATP

All the reactions of glycolysis can be grouped into ______ phases.

3

A single run of the citric acid cycle results in the production of two molecules of carbon dioxide, one molecule of ATP (or GTP), three molecules of ________, and one molecule of _______, from one acetyl group.

NADH FADH

The high-energy electrons that are used for oxidative phosphorylation come from __________ and __________.

NADH FADH2

The sources of high-energy electrons for oxidative phosphorylation include:

NADH FADH2

Which of the following are end products of glycolysis?

NADH Pyruvate ATP

During the oxidation of glyceraldehyde-3-phosphate:

NADH is produced

What four pathways are involved in the breakdown of glucose to carbon dioxide and water?

Citric acid cycle Oxidative phosphorylation Glycolysis Breakdown of pyruvate

In the second phase of glycolysis, a molecule of _______-1,6-________ is cleaved into two molecules of _________-3-phosphate.

Fructose-1,6-bisphosphate glyceraldehyde-3-phosphate

The products of the citric acid cycle include:

NADH ATP carbon dioxide FADH2

What are the products of the breakdown of a single pyruvate molecule?

One CO2 One NADH molecule One acetyl group

cleavage phase

a six carbon molecule is converted to two three-carbon molecules

The metabolic reactions that a cell uses to get energy from food molecules and release waste products are collectively called:

cellular respiration

During the process of _________, energy stored in a proton gradient is used to synthesize ATP from ADP and Pi.

chemiosmosis

The use of energy stored in a proton gradient to drive the synthesis of ATP is called

chemiosmosis

During glycolysis, one molecule of __________ is broken down into two molecules of pyruvate, driving the synthesis of ATP.

glucose

During the first phase of glycolysis, ATP is hydrolyzed so that phosphate groups can be added to:

glucose

Consider the net equation of cellular respiration. Which of the following molecules would be reactants?

glucose and oxygen

During glycolysis, fructose-1,6-bisphosphate is split into two three-carbon sugars. The rearrangement of one of these molecules results in the net production of two molecules of:

glyceraldehyde-3-phosphate

ATP is an allosteric inhibitor of phosphofructokinase, so when levels of ATP are high, _____ is slowed.

glycolysis

Most cancer cells overexpress the enzymes that are required for:

glycolysis

Tumors provide a favorable environment for glycolysis because their internal regions tend to be deficient in:

oxygen

The location of oxidative phosphorylation in prokaryotes is the _______ membrane and in eukaryotes is the _______ mitochondrial membrane.

plasma inner

The purpose of the energy investment phase of glycolysis is to:

prime glucose for the exergonic reactions to follow

The second stage of glycolysis is called the cleavage phase. The reactions of the cleavage phase break a six-carbon molecule into:

two three-carbon molecules

Arrange the sugar molecules that are involved in this phase in the order in which they are used in the pathway.

1. Glucose 2. Glucose-6-phosphate 3. Fructose-6-phosphate 4. Fructose-1,6-bisphosphate

The third stage of glycolysis is the energy liberation phase. Arrange the chemical intermediates that are produced in this phase in the correct order.

1. Glyceraldehyde-3-phosphate 2. 1,3-bisphosphoglycerate 3. 3-phosphoglyceate 4. 2-phosphoglycerate 5. phosphoenolpyruvate 6. pyruvate

Glycolysis consists of ________ reactions or steps.

10

Glycolysis results in a net gain of _________ ATP per glucose molecule.

2

The third stage of glycolysis (steps 6-10) is called the energy liberation phase. It produces a total of _________ molecule(s) of NADH and ________ molecule(s) of ATP for every molecule of glucose that enters the pathway. Note: This question is NOT asking about the net yield but the total.

2 & 4

For every glucose molecule that enters glycolysis, the energy liberation phase (steps 6-10) generates a total of

2 NADH and 4 ATP molecules.

Which of the following serve as REACTANTS in the net reaction of glycolysis? Select all that apply.

2 Pi2- 2 ADP2- 2 NAD+

Glycolysis is the breakdown of glucose into:

2 pyruvate molecules

The net products of glycolysis are:

2 pyruvate, 2 NADH, 2 H+, 2 ATP, and 2 H2O

During the cleavage stage of glycolysis, a molecule with ______ carbon atoms is broken into two molecules of _________-3-phosphate.

6 glyceraldehyde

Which of the following is the best description of the process of cellular respiration?

A means to extract energy from organic molecules

The three energy intermediates produced during cellular respiration are __________, ___________, and ___________.

ATP NADH FADH2 or FADH

energy liberation phase

ATP and NADH are synthesized

Energy investment phase

ATP is hydrolyzed, and its phosphate groups are attached to glucose

What happens during substrate-level phosphorylation?

An enzyme transfers a phosphate group from an organic molecule to ADP

In glycolysis, what is the net yield of ATP per molecule of glucose?

Two ATP molecules

Which of the following molecules are energy intermediates produced during cellular respiration?

FADH2 ATP NADH

The electron transport chain results in the oxidation of what energy intermediates produced in the earlier steps of cellular respiration?

FADH2 NADH

True or false: Glycolytic enzymes are not expressed in 80% of cancers.

False

four steps of cellular respiration in the correct order

Glycolysis, breakdown of pyruvate, citric acid cycle, and oxidative phosphorylation

In prokaryotes, where does oxidative phosphorylation occur?

Plasma membrane

What is the main function of oxidative phosphorylation?

Production of ATP

Why are phosphate groups added to glucose during the first phase of glycolysis?

To raise its free energy so that later reactions are exergonic

The pyruvate molecule produced in glycolysis undergoes a reaction that results in the production of one _________ group and one CO2 molecule.

acetyl, acetyl CoA, or acetyl-CoA

At high concentrations, ATP regulates the rate of glycolysis through:

allosteric inhibition of phosphofructokinase

Invaginations of the inner mitochondrial membrane:

are called cristae allow for greater ATP production increase surface area

The products of cellular respiration include:

carbon dioxide and water

The second phase of glycolysis is also called the ______ phase

cleavage

Glycolysis occurs in the:

cytosol

During the cleavage phase of glycolysis, fructose-1,6-bisphosphate is split into two different three-carbon molecules. These two molecules are:

dihydroxyacetone phosphate glyceraldehyde-3-phosphate

The first phase of glycolysis is also called the ______ phase

energy investment

three stages of glycolysis in the correct order

energy investment phase cleavage phase energy liberation phase

True or false: Glycolysis occurs in the mitochondria.

false

During the energy investment phase of glycolysis, glucose is converted to:

fructose-1,6-bisphosphate

The cristae increase the amount of ATP that can be made by:

increasing the surface area of the inner mitochondrial membrane

In eukaryotic cells, pyruvate breakdown, the citric acid cycle, and oxidative phosphorylation occur in the:

mitochondria

The removal of a phosphate from 1,3-bisphosphoglycerate allows for the transfer of the phosphate to ADP, producing ATP via _________-__________ phosphorylation.

substrate-level

The transfer of a high energy phosphate group from a phosphorylated organic molecule to ADP is referred to as

substrate-level phosphorylation

In eukaryotic cells, which of the following metabolic pathways occur in the mitochondria?

the breakdown of pyruvate the citric acid cycle oxidative phosphorylation

The hydrolysis of ATP early in glycolysis leads directly to:

the phosphorylation of glucose

During the first phase of glycolysis:

there is an ATP investment

True or false: Within tumors, glycolysis is favored under hypoxic conditions.

true

The number of ATP molecules hydrolyzed during the first stage of glycolysis is

two

Glycolysis involves the breakdown of one molecule of glucose into:

two molecules of pyruvate