Chapter 8: An Introduction To Metabolism Answer Key

AP Biology Reading Guide
Fred and Theresa Holtzclaw

Chapter 8: An Introduction to Metabolism

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Chapter 8: An Introduction to Metabolism
Concept 8.1 An organism’s metabolism transforms matter and energy, subject to the laws of thermodynamics
1.

Define metabolism.

2.

There are two types of reactions in metabolic pathways: anabolic and catabolic.
a. Which reactions release energy?
b. Which reactions consume energy?
c. Which reactions build up larger molecules?
d. Which reactions break down molecules?
e. Which reactions are considered “uphill”?
f. What type of reaction is photosynthesis?
g. What type of reaction is cellular respiration?
h. Which reactions require enzymes to catalyze reactions?

3.
What is free energy? What is its symbol?

Copyright © 2010 Pearson Education, Inc.

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AP Biology Reading Guide
Fred and Theresa Holtzclaw

Chapter 8: An Introduction to Metabolism

6.

For an exergonic reaction, is ∆G negative or positive?

7.

Is cellular respiration an endergonic or an exergonic reaction? What is ∆G for this reaction? 8.

Is photosynthesis endergonic or exergonic? What is the energy source that drives it?

9.

To summarize, if energy is released, ∆G must be what?

Concept 8.3 ATP powers cellular work by coupling exergonic reactions to endergonic reactions 10.

List the three main kinds of work that a cell does. Give an example of each.
(1)
(2)
(3)

11.

Here is a molecule of ATP. Label it. Use an arrow to show which bond is likely to break. Copyright © 2010 Pearson Education, Inc.

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AP Biology Reading Guide
Fred and Theresa Holtzclaw

Chapter 8: An Introduction to Metabolism

a. By what process will that bond break?
b. Explain the name ATP by listing all the molecules that make it up.
12.

When the terminal phosphate bond is broken, a molecule of inorganic phosphate P i is formed, and energy is
FYI: An essay question on the 2009 AP Biology exam asked students to identify the molecules that make up ATP. What are they again?
13.

What is energy coupling?

In many cellular reactions, a phosphate group is transferred from ATP to some other molecule in order to make the second molecule less stable. The second molecule is said to be _________________.

14.

Look for this amazing bit of trivia: If you could not regenerate ATP by phosphorylating ADP, how much ATP would you need to consume each day?

Concept 8.4 Enzymes speed up metabolic reactions by lowering energy barriers
15.

What is a catalyst?

Copyright © 2010 Pearson Education, Inc.

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AP Biology Reading Guide
Fred and Theresa