Post Lecture Quiz 4

Question 1

An inhibitor of phosphodiesterase activity would have which of the following effects?

Question options:

1)
block the activation of G proteins in response to epinephrine binding to its receptor

2)
decrease the amount of cAMP in the cytoplasm

3)
block the activation of protein kinase A

4)
block the response of epinephrine

5)
prolong the effect of epinephrine by maintaining elevated cAMP levels in the cytoplasm

Answer 1

prolong the effect of epinephrine by maintaining elevated cAMP levels in the cytoplasm

Question 2

Which of the following is a correct association?
:

1)
kinase activity and the addition of a tyrosine

2)
adenylyl cyclase activity and the conversion of cAMP to AMP

3)
phosphodiesterase activity and the removal of phosphate groups

4)
GTPase activity and hydrolysis of GTP to GDP

5)
phosphorylase activity and the catabolism of glucose

Answer 2

GTPase activity and hydrolysis of GTP to GDP

Question 3

At puberty, an adolescent female body changes in both structure and function of several organ systems, primarily under the influence of changing concentrations of estrogens and other steroid hormones. How can one hormone, such as estrogen, mediate so many effects?

Question options:

1)
Estrogen is produced in very large concentration and therefore diffuses widely.

2)
Estrogen binds to specific receptors inside many kinds of cells, each of which have different responses to its binding.

3)
Estrogen has specific receptors inside several cell types, but each cell responds in the same way to its binding.

4)
The subcomponents of estrogen, when metabolized, can influence cell response.

5)
Estrogen is kept away from the surface of any cells not able to bind it at the surface.

Answer 3

Estrogen binds to specific receptors inside many kinds of cells, each of which have different responses to its binding.

Question 4

Testosterone functions inside a cell by

1)
acting as a signal receptor that activates tyrosine kinases.

2)
acting as a steroid signal receptor that activates ion channel proteins.

3)
becoming a second messenger that inhibits nitric oxide.

4)
binding with a receptor protein that enters the nucleus and activates specific genes.

5)
coordinating a phosphorylation cascade that increases spermatogenesis.

Answer 4

binding with a receptor protein that enters the nucleus and activates specific genes.

Question 5

Caffeine is an inhibitor of phosphodiesterase. Therefore, the cells of a person who has recently consumed coffee would have increased levels of

Question options:

1)
phosphorylated proteins.

2)
activated G proteins.

3)
GTP.

4)
adenylyl cyclase.

5)
cAMP.

Answer 5

cAMP.

Question 6

A drug designed to inhibit the response of cells to testosterone would almost certainly result in which of the following?

Question options:

1)
a decrease in transcriptional activity of certain genes

2)
an increase in cytosolic calcium concentration

3)
lower cytoplasmic levels of cAMP

4)
an increase in receptor tyrosine kinase activity

5)
a decrease in G protein activity

Answer 6

a decrease in transcriptional activity of certain genes

Question 7

Why has C. elegans proven to be a useful model for understanding apoptosis?

Question options:

1)
The animal has as many genes as complex organisms, but finding those responsible is easier than in a more complex organism.

2)
The nematode undergoes a fixed and easy-to-visualize number of apoptotic events during its normal development.

3)
While the organism ages, its cells die progressively until the whole organism is dead.

4)
This plant has a long-studied aging mechanism that has made understanding its death just a last stage.

5)
All of its genes are constantly being expressed so all of its proteins are available from each cell.

Answer 7

The nematode undergoes a fixed and easy-to-visualize number of apoptotic events during its normal development.

Question 8

For living organisms, which of the following is an important consequence of the first law of thermodynamics?

Question options:

1)
Life does not obey the first law of thermodynamics.

2)
Organisms grow by converting energy into organic matter.

3)
The entropy of an organism decreases with time as the organism grows in complexity.

4)
The energy content of an organism is constant.

5)
The organism ultimately must obtain all of the necessary energy for life from its
environment.

Answer 8

The organism ultimately must obtain all of the necessary energy for life from its
environment.

Question 9

Which of the following is true of metabolism in its entirety in all organisms?

Question options:

1)
Metabolism depends on a constant supply of energy from food.

2)
Metabolism manages the increase of entropy in an organism.

3)
Metabolism depends on an organism’s adequate hydration.

4)
Metabolism uses all of an organism’s resources.

5)
Metabolism consists of all the energy transformation reactions in an organism.

Answer 9

Metabolism consists of all the energy transformation reactions in an organism.

Question 10

A molecule that is phosphorylated

Question options:

1)
has been oxidized as a result of a redox reaction involving the gain of an inorganic phosphate.

2)
has an increased chemical potential energy; it is primed to do cellular work.

3)
has less energy than before its phosphorylation and therefore less energy for cellular work.

4)
has been reduced as a result of a redox reaction involving the loss of an inorganic phosphate.

5)
has a decreased chemical reactivity; it is less likely to provide energy for cellular work.

Answer 10

has an increased chemical potential energy; it is primed to do cellular work.