Chapters 8, 9, 10, & 11 book questions

Question 1

Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as _______ is to _______.

Answer 1

exergonic; endergonic

Question 2

Most cells cannot harness heat to perform work because

Answer 2

temperature is usually uniform throughout a cell

Question 3

Which of the following metabolic processes can occur without a net influx of energy from some other process?

Answer 3

C6H12O6 + 6 O2 —> 6 CO2 + 6 H2O

Question 4

If an enzyme in solution is saturated with substrate, the most effective way to obtain a faster yield of products is to

Answer 4

add more of the enzyme

Question 5

Some bacteria are metabolically active in hot springs because

Answer 5

their enzymes have high optimal temperatures

Question 6

If an enzyme is added to a solution where its substrate and product are in equilibrium, what will occur?

Answer 6

Nothing; the reaction will stay at equilibrium

Question 7

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

Answer 7

H+ concentrations across the membrane holding ATP synthase

Question 8

Which metabolic pathway is common to both fermentation and cellular respiration of a glucose molecule?

Answer 8

glycolysis

Question 9

In mitochondria, exergonic redox reactions

Answer 9

provide the energy that establishes the proton gradient

Question 10

The final electron accepter of the electron transport chain that functions in aerobic oxidative phosphorylation is

Answer 10

oxygen

Question 11

What is the oxidizing agent in the following reaction?

pyruvate + NADH + H+ —> Lactate + NAD+

Answer 11

pyruvate

Question 12

When electrons flow along the electron transport chains of mitochondria, which of the following changes occur?

Answer 12

the pH of the matrix increases

Question 13

Most CO2 from catabolism is released during

Answer 13

the citric acid cycle

Question 14

Enzymes are described as catalysts, which means that they

Answer 14

increase the rate of the reaction without being consumed by the reaction

Question 15

The reduced form of the electron acceptor in glycolysis is

Answer 15

NADH

Question 16

As ATP levels accumulate, negative feedback causes cellular respiration to slow down. What is the name of the enzyme that is acted on by ATP in this negative feedback look?

Answer 16

phosphofructokinase

Question 17

Chemical energy is a type of

Answer 17

potential energy

Question 18

Light energy is a type of

Answer 18

kinetic energy

Question 19

The electrons stripped from glucose in cellular respiration end up in which compound?

Answer 19

water

Question 20

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

Answer 20

ATP, CO2, and ethanol (ethyl alcohol)

Question 21

The competitive inhibitor competes with the substrate for the _________ on the enzyme.

Answer 21

active site

Question 22

The light reactions of photosynthesis supply the calvin cycle with

Answer 22

ATP and NADPH

Question 23

Which of the following sequences correctly represents the flow of electrons during photosynthesis?

Answer 23

H2O —> NADPH —> Calvin Cycle

Question 24

How is photosynthesis similar in C4 plants and CAM plants?

Answer 24

In both cases, rubisco is not used to fix carbon initially

Question 25

Which of the following statements is a correct distinction between autotrophs and heterotrophs?

Answer 25

Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic

Question 26

Which of the following does not occur during the Calvin cycle?

Answer 26

release of oxygen

Question 27

In mechanism, photophosphorylation is most similar to

Answer 27

oxidative phosphorylation in cellular respiration

Question 28

Which process is most directly driven by light energy?

Answer 28

removal of electrons from chlorophyll molecules

Question 29

Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because

Answer 29

they amplify the original signal manyfold

Question 30

Binding of a signaling molecule to which type of receptor leads directly to a change in the distribution of ions on opposite sides of the membrane?

Answer 30

ligand-gated ion channel

Question 31

The activation of receptor tyrosine kinases is characterized by

Answer 31

dimerization and phosphorylation

Question 32

Lipid-soluble signaling molecules, such as testosterone, cross the membranes of all cells but affect only target cells because

Answer 32

intracellular receptors are present only in target cells

Question 33

Consider this pathway:
epinephrine —> G protein-coupled receptor —> G protein —> adenylyl cyclase —> cAMP.
Identify the second messenger.

Answer 33

cAMP

Question 34

Apoptosis involves

Answer 34

• fragmentation of the DNA
• cell-signaling pathways
• activation of cellular enzymes
• digestion of cellular contents by scavenger cells

Question 35

Apoptosis does not involve

Answer 35

lysis of the cell

Question 36

Which observation suggested to Sutherland the involvement of a second messenger in epinephrine’s effect on liver cells?

Answer 36

Glycogen breakdown was observed only when epinephrine was administered to intact cells

Question 37

Protein phosphorylation is commonly involved with all of the following EXCEPT

Answer 37

activation of G protein-coupled receptors

Question 38

Protein phosphorylation is commonly involved with

Answer 38

• regulation of transcription by extracellular signaling molecules
• enzyme activation
• activation of receptor tyrosine kinases
• activation of protein kinase molecules