Question 1

The recognition of a chemical signal by a receptor protein in the membrane is most similar to ____.

Accepted Answer

A)   mRNA specifying the sequence of amino acids in a polypeptide
B)   binding of a specific substrate to the active site of an enzyme
C)   turning on gene transcription
D)   allosteric regulation of proteins
E)   an enzyme requiring a specific optimum pH and temperature for activity

Question 2

Signaling molecules bind to the ____ region of a receptor tyrosine kinase.

Accepted Answer

A)   intracellular
B)   hydrophobic
C)   extracellular
D)   cytoplasmic
E)   intramembrane

Question 3

Estrogen receptor (ER)  α typically ____, while ERβ typically ____.

Accepted Answer

A)   stimulates DNA binding; inhibits DNA binding
B)   stimulates cell proliferation; inhibits cell proliferation
C)   stimulates channel opening; inhibits channel opening
D)   inhibits DNA binding; stimulates DNA binding
E)   inhibits cell proliferation; stimulates cell proliferation

Question 4

In order for a target cell to receive a signal, it must possess a ____ specific to the signaling molecule.

Accepted Answer

A)   glycolipid
B)   glycoprotein
C)   receptor
D)   transfer protein
E)   hormone

Question 5

What is the function of signal transduction?

Accepted Answer

Signal transduction refers to the proces...

Question 6

An active phosphatase adds phosphate groups to other molecules.

Accepted Answer

A) True 
 B)False

Question 7

Substance A is synthesized in the liver, travels through the circulatory system bound to a carrier protein, and causes a change in gene expression in a target cell. This is an example of ____.

Accepted Answer

A)   autocrine signaling
B)   paracrine signaling
C)   long-distance signaling
D)   local signaling
E)   communication by direct contact

Question 8

Why are steroid hormones bound to carrier proteins in the blood?

Accepted Answer

A)   to prevent them from entering non-target cells
B)   to keep them in an inactivate state
C)   to mask hydrophobic groups on the steroids to allow for circulation in the blood
D)   to help them bind to surface receptors and trigger a cellular response
E)   to help them bind to surface receptors and trigger endocytosis

Question 9

What is the second step of signal transduction?

Accepted Answer

A)   reception
B)   transduction
C)   differentiation
D)   division
E)   response

Question 10

Receptors for polar molecules are found ____, while receptors for nonpolar molecules are located ____.

Accepted Answer

A)   on the cell surface; within the cell
B)   within the cell; on the cell surface
C)   on the cell surface; on the nuclear membrane
D)   on the nuclear membrane; on the cell surface
E)   on the cell surface; within the lipid bilayer

Question 11

In breast cancer, ERα is often lost, which increases cell proliferation.

Accepted Answer

A) True 
 B)False

Question 12

Many signal transduction pathways utilize second messengers to ____.

Accepted Answer

A)   transport a signal through the lipid bilayer of the plasma membrane
B)   relay a signal from the outside of the cell to the inside
C)   relay a signal from the inside of the cell to the outside
D)   decrease the message once the signaling molecules have left the receptor
E)   relay the message from the inner surface of the plasma membrane throughout the cytoplasm

Question 13

Why is cell communication considered evolutionarily ancient?

Accepted Answer

Some protein components of cell communic...

Question 14

The amino acid targets of protein kinases in all GPCR pathways are ____.

Accepted Answer

A)   serine and glycine
B)   serine and tyrosine
C)   serine and threonine
D)   glycine and tyrosine
E)   glycine and threonine

Question 15

How do cells distinguish between estrogen and testosterone?

Accepted Answer

A)   Only male cells respond to testosterone, and female cells respond to estrogen.
B)   Eestrogen is hydrophilic and binds to surface receptors, while testosterone is hydrophobic and binds to internal receptors.
C)   Eestrogen and testosterone have similar functional groups but different basic structures that are easily distinguished by their individual receptors.
D)   Estrogen and testosterone have the same basic structures, but different side chains that are easily distinguished by their individual receptors.
E)   Estrogen and testosterone bind to different carrier proteins, which help receptors distinguish between the two molecules.

Question 16

Quorum sensing ____.

Accepted Answer

A)   allows receptors from different parts of the cell to work together to elicit a response
B)   allows receptors from different parts of the body to work together to elicit a response
C)   uses multiple cellular pathways to elicit a specific response
D)   is a type of communication between unicellular organisms
E)   is a type of cell communication between multicellular organisms

Question 17

After the binding of a signaling molecule to a surface receptor, the signaling molecule does not enter the cell.

Accepted Answer

A) True 
 B)False

Question 18

In the first step of signal transduction, what is the trigger for the cellular response?

Accepted Answer

A)   target protein
B)   kinase
C)   ligand
D)   second messenger
E)   effector

Question 19

Cell signaling pathways evolved ____.

Accepted Answer

A)   thousands of years ago
B)   in multicellular organisms
C)   hundreds of millions of years ago
D)   tens of billions of years ago
E)   1 million years ago

Question 20

What happens immediately after a signaling molecule binds to an RTK?

Accepted Answer

A)   receptor dimerization
B)   receptor trimerization
C)   receptor denaturation
D)   receptor polymerization
E)   receptor hydrolysis

Exam 9: Cell Communication

In breast cancer, ERα is often lost, which increases cell proliferation.

Correct AnswerverifiedShow Answer

In the first step of signal transduction, what is the trigger for the cellular response?

Correct AnswerverifiedShow Answer

The recognition of a chemical signal by a receptor protein in the membrane is most similar to ____.

Correct AnswerverifiedShow Answer

Estrogen receptor (ER) α typically ____, while ERβ typically ____.

Correct AnswerverifiedShow Answer

The amino acid targets of protein kinases in all GPCR pathways are ____.

Correct AnswerverifiedShow Answer

What is the function of signal transduction?

Correct AnswerverifiedSignal transduction refers to the proces...View AnswerShow Answer

How do cells distinguish between estrogen and testosterone?

Correct AnswerverifiedShow Answer

Quorum sensing ____.

Correct AnswerverifiedShow Answer

An active phosphatase adds phosphate groups to other molecules.

Correct AnswerverifiedShow Answer

In order for a target cell to receive a signal, it must possess a ____ specific to the signaling molecule.

Correct AnswerverifiedShow Answer

What happens immediately after a signaling molecule binds to an RTK?

Correct AnswerverifiedShow Answer

Why are steroid hormones bound to carrier proteins in the blood?

Correct AnswerverifiedShow Answer

Cell signaling pathways evolved ____.

Correct AnswerverifiedShow Answer

Many signal transduction pathways utilize second messengers to ____.

Correct AnswerverifiedShow Answer

Signaling molecules bind to the ____ region of a receptor tyrosine kinase.

Correct AnswerverifiedShow Answer

Substance A is synthesized in the liver, travels through the circulatory system bound to a carrier protein, and causes a change in gene expression in a target cell. This is an example of ____.

Correct AnswerverifiedShow Answer

After the binding of a signaling molecule to a surface receptor, the signaling molecule does not enter the cell.

Correct AnswerverifiedShow Answer

Receptors for polar molecules are found ____, while receptors for nonpolar molecules are located ____.

Correct AnswerverifiedShow Answer

Why is cell communication considered evolutionarily ancient?

Correct AnswerverifiedSome protein components of cell communic...View AnswerShow Answer

What is the second step of signal transduction?

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Estrogen receptor (ER) α typically , while ERβ typically .

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Signal transduction refers to the proces...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Receptors for polar molecules are found , while receptors for nonpolar molecules are located .

Correct Answer
verified

Correct Answer
verified
Some protein components of cell communic...
View Answer

Correct Answer
verified