Ch 8

Question 1

An agent that influences the properties of cells is called a(n)

Answer 1

signal

Question 2

Plant cells produce hormones that determine the pattern of cell elongation such that the plant will grow toward light. The hormone effect is an example of an:

Answer 2

outgoing signal

Question 3

Cell signaling is important because

Answer 3

• cells need to respond to a changing environment.

* cells need to communicate with each other.

Question 4

What type of signaling involves signals that pass through a cell junction from the cytosol of one cell to the cytosol of an adjacent cell?

Answer 4

Direct Intercellular signaling

Question 5

during ____ dependent signaling, membrane-bound signals bind to receptors on adjacent cells.

Answer 5

contact

Question 6

the process thru which cells can detect, interpret, and respond to signals in their environment
-included incoming and outgoing signals

Answer 6

Cell communication

Question 7

An example of an incoming signal in cell communication is:

Answer 7

ultraviolet light

Question 8

Cell signaling allows cells to detect and respond to signals from their ___ and from other cells

Answer 8

environment

Question 9

Signals passing through a cell junction from the cytosol of one cell to an adjacent cell is a description of ___ _____ ______

Answer 9

direct intercellular signaling

Question 10

If a cell secretes a signal that binds to its own receptors or those of neighboring cells of the same time, the process is called signaling.

Answer 10

autocrine

Question 11

Membrane-bound signals bind to receptors on adjacent cells in the following signaling mechanism known as

Answer 11

contact dependent signaling.

Question 12

In signaling, a cell secretes a signaling molecule that does not affect the cell secreting the signal but influences the behavior of target cells in close proximity.

Answer 12

Paracrine

Question 13

Which signaling process occurs when cells release signals that travel long distances through the blood of a vertebrate or the vascular system of a plant?
Multiple choice question.

Answer 13

Endocrine signaling

Question 14

Cellular signaling involves an interaction between a signaling molecule from one cell and a(n) protein on or in another cell

Answer 14

receptor

Question 15

The stage of cell signaling that immediately follows receptor activation is called:

Answer 15

signal transduction

Question 16

When cell density is high, the density of autocrine signals is

Answer 16

high

Question 17

What is the third and final stage of cell signaling?

Answer 17

Cellular response

Question 18

In what type of signaling does a specific cell produce a signaling molecule that does not affect the cell secreting the signal but influences the behavior of target cells in close proximity?

Answer 18

Paracrine

Question 19

Match each step of cell-to-cell signaling with the appropriate description.

Answer 19

i. Receptor Activation = A signaling molecule binds to a receptor.
ii. Signal Transduction = The signal is converted to a different type of signal, often resulting in the production of an intracellular signaling molecule.
iii. Cellular Response = An enzyme, structural protein, or transcription factor is altered.

Question 20

cells produce hormones that travel long distances or even diffuse through the air to affect other cells.

Answer 20

endocrine signaling

Question 21

Identify the stage of cell signaling where a signaling molecule binds to a receptor, causing a conformational change in the receptor.

Answer 21

Receptor activation

Question 22

During cellular signaling, what event causes the receptor to become activated?

Answer 22

A signaling molecule binds to it.

Question 23

In a ligand-receptor complex, what term stands for dissociation constant?

Answer 23

Kd

Question 24

What is the second stage of cell signaling?

Answer 24

Signal transduction

Question 25

The three categories of cell surface receptors are:

Answer 25

enzyme-linked receptors
ligand-gated ion receptors
G-protein-coupled receptors

Question 26

The last stage of a cell signaling pathway is the

Answer 26

cellular response

Question 27

Enzyme-linked receptor

Answer 27

The receptor phosphorylates itself or another protein.

Question 28

G-protein-coupled receptor

Answer 28

An intracellular G protein releases GDP and binds to GTP.

Question 29

Ligand-gated ion channel =

Answer 29

Ions move across the plasma membrane of the cell.

Question 30

Steroid hormone recepto

Answer 30

The receptor binds to DNA and activates the transcription of specific genes.

Question 31

Put the steps involved in a cell-to-cell signaling pathway in the correct order.

Answer 31

1. Binding of a signaling molecule to receptor
2. intracellular signal transduction pathway
3. Cellular response

Question 32

During the receptor activation stage of cell signaling, a signaling molecule binds to a receptor and causes a change in the receptor.

Answer 32

conformational

Question 33

When a signaling molecule binds to an enzyme-linked receptor, a conformational change is transmitted through the membrane-embedded portion of the protein. This conformational change causes the intracellular

Answer 33

catalytic domain to become active

Question 34

What type of interaction occurs between a ligand and its receptor?

Answer 34

Non-covalent and specific

Question 35

What is the function of protein kinases?

Answer 35

They add phosphate groups to proteins.

Question 36

Which of the following are types of cell surface receptors?

Answer 36

G-protein-coupled receptor
Ligand-gated ion channel
Enzyme-linked receptor

Question 37

proteins are intracellular proteins that interact with G-protein-coupled receptors.

Answer 37

G

Question 38

Enzyme-linked receptor

Answer 38

Activation of the receptor’s catalytic domain

Question 39

G-protein-coupled receptor

Answer 39

Interaction of the receptor with an intracellular G protein

Question 40

Ligand-gated ion channel

Answer 40

Formation of an open channel by the receptor

Question 41

G proteins are so named because of their ability to bind:

Answer 41

GTP and GDP

Question 42

In the first step of the signal transduction pathway involving cAMP, a signal molecule binds to and activates a receptor called ____

Answer 42

GPCR and

GTP

Question 43

The change that occurs when a signaling molecule binds to the extracellular domain causes the catalytic domain to become:

Answer 43

active

Question 44

Activation of a GPCR causes a G protein to bind ___. The activated G protein stimulates adenylyl cyclase to synthesize ___. This second messenger ultimately activates the enzyme ___, which phosphorylates cellular proteins that carry out the cellular response.

Answer 44

GTP; cAMP; PKA

Question 45

The enzymes that transfer a phosphate group from ATP to specific amino acids in a protein are known as ____

Answer 45

protein kinases

Question 46

Select the event that occurs last after the activation of a G-protein coupled receptor.

Answer 46

A G protein hydrolyzes GTP to GDP.

Question 47

Intercellular proteins that bind guanosine triphosphate (GTP) and

Answer 47

G - proteins

Question 48

When a signaling molecule binds to a(n) _______-gated ion channel, the channel opens and allows the flow of ions through the membrane

Answer 48

ligand

Question 49

What proteins can bind GTP and GDP?

Answer 49

G-Protein

Question 50

Some signaling molecules must pass through the ____ ____ before activating a receptor located in the cytosol or the nucleus.

Answer 50

plasma membrane

Question 51

the binding of a signaling molecule activates

Answer 51

GPCR

Question 52

the G protein binds to

Answer 52

GTP

Question 53

the α subunit dissociates from

Answer 53

β/γ dimer

Question 54

Put the steps involved in a signal transduction cascade involving a G-protein-coupled receptor in the correct order.

Answer 54

1) A ligand binds to to a G-protein-coupled receptor.
2) An intracellular G protein binds to GDP.
3) Adenylyl cyclase synthesizes cAMP.
4) Protein kinase A is activated.
5) Cellular proteins become phosphorylated and cause a cellular response.

Question 55

When an estrogen-receptor complex is formed, it undergoes a conformational change, which allows it to form a dimer with another estrogen-receptor complex. What does this dimer activate when it binds with DNA?

Answer 55

The transcription of specific genes

Question 56

Put the events that occur during the activation of a G-protein-coupled receptor in the correct order, beginning with the first event at the

Answer 56

1. a signaling molecule binds to a GPCR.
2. the GPCR binds to a G protein
3. the G protein exchanges GDP for GTP
4. The G protein subunits dissociate

Question 57

What happens when a signaling molecule binds to a ligand-gated ion channel?

Answer 57

The channel opens and allows the flow of ions through the membrane.