Chapter 17

Question 1

direct interaction of a cell with its neighbor, (e.g., via integrins and cadherins).

Answer 1

Direct cell-cell signaling

Question 2

three categories are based on the distance over which signals are transmitted.

Answer 2

Signaling by secreted molecules

Question 3

Secreted by specialized endocrine cells and carried through the circulation to target cells at distant body sites. Example: estrogen

Answer 3

Endocrine signaling

Question 4

Released by one cell act on neighboring target cells. Example: neurotransmitters

Answer 4

Paracrine signaling

Question 5

Cells respond to signaling molecules that they themselves produce.
Example: T lymphocytes respond to antigens by making a growth factor that drives their own proliferation.

Answer 5

Autocrine signaling

Question 6

respond to small hydrophobic molecules that can diffuse across the plasma membrane.

Answer 6

Intracellular receptors

Question 7

Intracellular receptors examples

Answer 7

Steroid hormones, thyroid hormone, vitamin D3, and retinoic acid.

Question 8

Steroid hormones are synthesized from:

Answer 8

cholesterol

Question 9

Testosterone, estrogen, and progesterone are the

Answer 9

sex steroids

Question 10

Corticosteroids from the adrenal gland:
(2 types)

Answer 10

Glucocorticoids
Mineralocorticoids

Question 11

an insect hormone that triggers metamorphosis of larvae to adults.

Answer 11

Ecdysone

Question 12

plant steroid hormones that control several processes, including cell growth and differentiation.

Answer 12

Brassinosteroids

Question 13

synthesized from tyrosine in the thyroid gland; important in development and metabolism.

Answer 13

Thyroid hormone

Question 14

regulates Ca2+ metabolism and bone growth.

Answer 14

Vitamin D3

Question 15

synthesized from vitamin A; important in vertebrate development.

Answer 15

Retinoic acid

Question 16

Glucocorticoid receptor is bound to _____ chaperones in the absence of hormone.

Answer 16

Hsp90

Question 17

associated with a corepressor complex and represses transcription of target genes in the absence of a hormone

Answer 17

thyroid hormone receptor

Question 18

a paracrine signaling molecule in the nervous, immune, and circulatory systems.

Answer 18

Nitric oxide

Question 19

_____ induces muscle cell relaxation and blood vessel dilation.

Answer 19

cGMP

Question 20

Many neurotransmitter receptors are ______ ion channels.

Answer 20

ligand-gated

Question 21

Other neurotransmitter receptors are coupled to __ proteins

Answer 21

G

Question 22

Peptide signaling molecules include (3 things)

Answer 22

1. peptide hormones, 2. neuropeptides, and 3. polypeptide growth factors.

Question 23

include insulin, glucagon, and pituitary gland hormones (e.g., growth hormone, follicle-stimulating hormone, prolactin).

Answer 23

Peptide hormones

Question 24

act as neurotransmitters and as neurohormones—natural analgesics that decrease pain responses; they bind to the same receptors on brain cells as morphine does.

Answer 24

Enkephalins and endorphins

Question 25

a member of the neurotrophin family that regulates development and survival of neurons.

Answer 25

Nerve growth factor

Question 26

stimulates cell proliferation. It is the prototype for the study of growth factors.

Answer 26

Epidermal growth factor

Question 27

stored in blood platelets and released during blood clotting at the site of a wound.

Answer 27

Platelet-derived growth factor

Question 28

regulate development and differentiation of blood cells and activities of lymphocytes during the immune response.

Answer 28

Cytokines

Question 29

remain associated with the plasma membrane and function as signaling molecules in direct cell-cell interactions.

Answer 29

Membrane-anchored growth factors

Question 30

The surface receptors regulate intracellular enzymes, which then transmit signals from the receptor to a series of additional intracellular targets.

Answer 30

Intracellular signal transduction

Question 31

the largest family of cell surface receptors

Answer 31

G protein-coupled receptors

Question 32

synthesizes cAMP

Answer 32

adenylyl cyclase

Question 33

G proteins have three subunits designated α, β, and γ. They are called:

Answer 33

heterotrimeric G proteins.

Question 34

α and βγ complex then ______ from the receptor and interact with their targets.

Answer 34

dissociate

Question 35

In 1958 Sutherland discovered that epinephrine action was mediated by an increase in cyclic AMP (cAMP), leading to the concept of cAMP as a

Answer 35

second messenger.

Question 36

cAMP is degraded to _____ by cAMP phosphodiesterase.

Answer 36

AMP

Question 37

cAMP effects are mediated by cAMP-dependent protein kinase, or:

Answer 37

protein kinase A.

Question 38

In many animal cells, increases in cAMP activate transcription of genes that have a regulatory sequence called

Answer 38

cAMP response element (CRE).

Question 39

The free catalytic subunit of protein kinase A goes to the nucleus and phosphorylates transcription factor

Answer 39

CREB

Question 40

Phosphorylation of CREB leads to recruitment of

Answer 40

coactivators

Question 41

phosphorylate their substrates on tyrosine residues.

Answer 41

tyrosine kinases

Question 42

Receptor tyrosine kinases includes the receptors for most ________ growth factors.

Answer 42

polypeptide

Question 43

Ligand binding induces _________ of receptors, and cross-phosphorylation of associated nonreceptor tyrosine kinases.

Answer 43

dimerization

Question 44

a cascade of protein kinases that is highly conserved in evolution, found in all eukaryotic cells.

Answer 44

MAP kinase pathway

Question 45

MAP kinases initially found in mammalian cells belong to the _____ family.

Answer 45

ERK (extracellular signal-regulated kinase)

Question 46

The role of ERK signaling emerged from studies of _____ proteins

Answer 46

Ras

Question 47

Ras is activated by _____ that stimulate exchange of GDP for GTP.

Answer 47

GEFs

Question 48

A primary response to growth factor stimulation is rapid transcription of

Answer 48

immediate-early genes.

Question 49

Specificity of MAP kinase signaling is maintained partly by physical association on

Answer 49

scaffold proteins.

Question 50

PIP2 is phosphorylated PI to yield the second messenger _____

Answer 50

PIP3