BIO 111 Chapter Notes - Chapter 11: G Protein–Coupled Receptor, Tyrosine Kinase, Tyrosine

QUESTION 1

Which of the following is an example of an extracellular signal molecule?

2 points

QUESTION 2

Nuclear hormone receptors _____

2 points

QUESTION 3

Which of the following does not occur when a receptor tyrosine kinase is bound by ligand?

2 points

QUESTION 4

Which of these is a logical signal-transduction pathway?

2 points

QUESTION 5

Which of the following is an example of signal amplification?

2 points

QUESTION 6

Consider a signal transduction pathway that utilizes cAMP as a second messenger to activate PKA (Protein Kinase A). Which of the following situations will result in the cellular response?

2 points

QUESTION 7

Which of the following is found in only some signal transduction pathways? [In other words, which is not found in all signal transduction pathways?]

2 points

QUESTION 8

The enzyme that specifically catalyzes the conversion of ATP to cAMP is:

2 points

QUESTION 9

If an animal cell suddenly lost the ability to produce GTP, what might happen to its signaling system?

2 points

QUESTION 10

A hormone signal is sent from the brain to other parts of the body via the bloodstream. Why do only certain cells respond to this signal?

1. How does sexual reproduction compare to DNA transfers inprokaryotes?
I. Both increase genetic diversity.
II. Sexual reproduction results in greater evolutionarychange.
III. DNA transfer in prokaryotes allows for fewer errors andmutations.

a. I only

b. I and II

c. I and III

d. I, II, and III

2. What type of receptor is described in the followingparagraph?

Binding of a signaling molecule to this type of receptor uses anenzyme to remove a phosphate group from an ATP molecule to activateanother receptor. The activated receptor can be recognized by relayproteins inside the cell, which bind to the receptor and changeshape. These activated proteins then trigger a transduction pathwaythat leads to some sort of cellular response.

a. intracellular receptor

b. ligand-gated ion channel

c. g protein-coupled receptor

d. receptor tyrosine kinase

3. Yeast cells, plant cells, and mammal cells all share manysimilarities in cell signaling. This provides evidence that

a. cell-signaling mechanisms are only found in organisms that usemethods of sexual reproduction

b. intercellular communication evolved as a way for multicellularorganisms to coordinate cell functions

c. eukaryotic cells use signal transduction pathways whileprokaryotic cells use a more primitive form of signaling

d. signal transduction pathways appeared in cells before theevolution of multicellular organisms

Question 22

What intrinsic enzymatic activity do G proteins have?

They are ATPases

They are glycosidases

They are GTP synthases

They are GTPases

Question 23

How are G proteins activated?

The GTP dissociates from the G protein and GDP associates with the G protein

The GDP dissociates from the G protein and GTP associates with the G protein

The G protein synthesizes GTP from GDP

The G protein synthesizes GTP from ATP

Question 24

How are G proteins inactivated?

Hydrolyze ATP

Bind GTP

Bind ATP

Hydrolyze GTP

Question 25

What is a GTPase activating protein (GAP)?

It hydrolyzes GTP

It promotes release of GDP and binding of GTP of a G protein

It speeds up the rate of GTPase activty of a G protein

Question 26

What is a guanine nucleotide exchange factor (GEF)?

It speeds up the rate of GTPase activty of a G protein

It hydrolyzes GTP

It promotes release of GDP and binding of GTP to a G protein

Question 27

Which of the following types of enzyme activate G proteins?

GAP

GEF

Question 28

Which of the following types of enzyme inactivate G-proteins?

GAP

GEF

Question 29

What is receptor internalization and recycling?

It is when the receptor is co-translationally imported into the ER before being degraded by the unfolded protein response

It is when the receptor is endocytosed and then the vesicle fuses with the endosome, releases ligand and the receptor is returned to the plasma membrane

It is when the receptor is digested with proteases into amino acids and those amino acids are used to synthesize a new receptor

It is when the receptor cycles in and out of the nucleus

Question 30

How do large proteins get into the nucleus?

Simple diffusion

Facilitated diffusion through the nuclear pore

Active transport through the nuclear pore

Question 31

How easy is it for the following reaction to occur?

ADP + Pi → ATP

This is very exergonic and highly favorable

This is very endergonic and highly unfavorable

This is slightly exergonic and somewhat favorable

Question 32

The hydrolysis of ATP is highly...

Exergonic

Endergonic