bio chapter 9

Question 1

Which one of the following is NOT a cell surface-type receptor?

Answer 1

steroid receptor

Question 2

What determines the specificity of a receptor protein

Answer 2

the ligand-binding site

Question 3

Many pathologies are the result of a problem with cell signaling. Which of the following pathologies best exemplifies this fact?

Answer 3

Cancer, caused by a truncated receptor that is now stuck in the activated form

Question 4

What does a ligand-gated channel

Answer 4

It allows for the movement of ions across the plasma membrane

Question 5

Why dont steroid hormones bind to transmembrane cell-surface receptors?

Answer 5

steroid hormones are nonpolar and will cross the cell’s plasma membrane, binding to receptors inside the cell

Question 6

A researcher is using a small molecule inhibitor to manipulate a signaling pathway. This inhibitor prevents phosphorylation and most likely targets a :

Answer 6

receptor kinase

Question 7

Given that most ligands form covalent bonds with their associated receptors, these complexes are more-or-less permanent and can only be broken through the use of ATP

Answer 7

FALSE

Question 8

Notch and Delta are both transmembrane proteins, involved in cell communication in the developing nervous system of vertebrate animals. What makes Notch different from Delta

Answer 8

Notch is a receptor and Delta is a signaling molecule

Question 9

Which one of the following initiates signal termination

Answer 9

The release of signal molecules from their receptors

Question 10

Which of the following is NOT a true statement about receptors that are localized to the nucleus?

Answer 10

They bind polar ligands

Question 11

How does an “activated” receptor transfer information into the cell

Answer 11

through a conformation change

Question 12

Why dont steroid hormones bind to transmembrane cell-surface receptors

Answer 12

steroid hormones are nonpolar and will cross the cells plasma membrane, binding to receptors inside the cell

Question 13

Which one of the following initiates signal termination

Answer 13

the release of signal molecules from their receptors

Question 14

Which of the following is not a true statement about receptors that are localized to the nucleus

Answer 14

they bind polar ligands

Question 15

In cell communication, which one of the following is a requirement of the responding cell?

Answer 15

it must have receptor proteins

Question 16

Where would you expect to find the receptor for a nonpolar ligand?

Answer 16

either in the nucleus of the cell or in the cytosol

Question 17

To what does the term ligand refer to?

Answer 17

a signaling molecule

Question 18

Which type of protein adds a phosphate group to another molecule

Answer 18

kinase

Question 19

signal transduction results in:

Answer 19

A response by the cell

Question 20

Growth factors such as platelet-derived growth factor function in:

Answer 20

paracrine signaling

Question 21

Which of the following is NOT an essential element involved in communication between all cells?

Answer 21

transduction element

Question 22

Which of the following is a cellular response to signal transduction

Answer 22

• *a change in the proteins found in the cytosol
• *the release of more cytosol signal molecules
• *a change in the activity of an enzyme

Question 23

Which if the correct order for these stages in cell signaling?

Answer 23

receptor activation, signal transduction, response

Question 24

Endocrine signaling is

Answer 24

Through the bloodstream far away

Question 25

Autocrine signaling is

Answer 25

Same molecule

Question 26

Paracrine symboling is

Answer 26

Very close molecules

Question 27

Juxtacrine signaling is

Answer 27

Connected cells

Question 28

The oxygen produced in photosynthesis comes from water, not carbon dioxide

Answer 28

.