BI203 Lecture 21: Cell Signaling - Slides 16-30 (Types of Signaling Molecules)

Question 1

___ ___ control all aspects of cell behavior:

metabolism, movement, proliferation, differentiation, survival.

Answer 1

extracellular signals

Question 2

A variety of signaling molecules are secreted or expressed on the surface of one cell, and bind to ___ expressed by other cells.

Answer 2

receptors

Question 3

Example of extracellular signals controlling proliferation:

___ ___ ___ (PDGF) is stored in blood platelets and released during blood clotting at the site of a wound.

It stimulates proliferation of fibroblasts, contributing to regrowth of the damaged tissue.

Answer 3

Platelet-derived growth factor (PDGF)

Question 4

Example of extracellular signals controlling metabolism:

___ regulating glycogen breakdown.

Answer 4

epinephrine (adrenaline)

Question 5

Cellular responses elicited by extracellular signals occur via cell signaling ___.

Answer 5

cascades

Question 6

Many ___ arise from problems in signaling pathways that control normal cell proliferation.

Much of our understanding of cell signaling has come from the study of cancer cells.

Answer 6

cancers

Question 7

At least ___% of human genes encode signaling molecules.

Answer 7

12%

Question 8

___ modes of cell signaling:

Answer 8

2

Question 9

Two modes of cell signaling:

Answer 9

Direct cell-cell signaling, Signaling by secreted molecules

Question 10

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

Answer 10

Direct cell-cell signaling

Question 11

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

Answer 11

Signaling by secreted molecules

Question 12

___ ___ - Signaling molecules (hormones) are secreted by specialized endocrine cells and carried through the circulation to target cells at distant body sites. Examples: epinephrine and estrogen.

Answer 12

Endocrine Signaling

Question 13

Endocrine Signaling - Signaling molecules (___) are secreted by specialized endocrine cells and carried through the circulation to target cells at distant body sites. Examples: ___ and ___.

Answer 13

hormones, epinephrine (adrenaline), estrogen

Question 14

___ ___ - Molecules released by one cell act on neighboring target cells. Example: neurotransmitters.

Answer 14

Paracrine Signaling

Question 15

Paracrine Signaling - Molecules released by one cell act on neighboring target cells. Example: ___.

Answer 15

neurotransmitters

Question 16

___ ___ - 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, thereby amplifying the immune response.

Answer 16

Autocrine Signaling

Question 17

Autocrine Signaling - Cells respond to signaling molecules that they themselves produce. Example: ___ ___ respond to ___ by making a growth factor that drives their own proliferation, thereby amplifying the immune response.

Answer 17

T lymphocytes, antigens

Question 18

Signaling molecules that cross the plasma membrane:

Answer 18

steroid hormones, gases

Question 19

___ ___ = Mostly hydrophobic molecules w/ similar structures.

Answer 19

steroid hormones

Question 20

Steroid hormones are synthesized from ___.

Answer 20

cholesterol

Question 21

___, ___, and ___ are the sex steroids, produced by the gonads.

Answer 21

testosterone, estrogen, progesterone

Question 22

___ are steroids produced by the adrenal gland.

Answer 22

corticosteroids

Question 23

___ - Stimulate production of glucose.

Answer 23

glucocorticoids

Question 24

___ - Act on the kidneys to regulate salt and water balance.

Answer 24

mineralocorticoids

Question 25

___ ___ - Synthesized from tyrosine in the thyroid gland; important in development and metabolism.

Answer 25

thyroid hormone

Question 26

___ ___ regulates Ca2+ metabolism and bone growth.

Answer 26

Vitamin D3

Question 27

___ ___ and ___ - Synthesized from vitamin A; important in vertebrate development.

Answer 27

Retinoic acid, retinoids

Question 28

Steroid hormones, thyroid hormone, vitamin D3, & retinoic acid all bind & regulate ___ ___.

Answer 28

nuclear receptors

Question 29

Nuclear receptors are ___ ___ that have domains for ligand binding, DNA binding, and transcriptional activation.

Answer 29

transcription factors

Question 30

In the absence of ___ ___, the ___ ___ receptor is associated with a corepressor complex and represses transcription of target genes.

___ ___ binding results in activation of transcription.

Answer 30

thyroid hormone

Question 31

___ ___ (NO) is a paracrine signaling molecule in the nervous, immune, and circulatory systems.

It can cross the plasma membrane and alter the activity of enzymes. It is synthesized from arginine.

Answer 31

Nitric oxide (NO)

Question 32

NO binding stimulates the synthesis of ___ ___.

___ ___ induces muscle cell relaxation and blood vessel dilation.

Answer 32

cyclic GMP

Question 33

___ carry signals between neurons or from neurons to other cells.
They are released when an action potential arrives at the end of a neuron.

Answer 33

Neurotransmitters

Question 34

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

Answer 34

peptide hormones

Question 35

___ ___ ___ (EGF) stimulates cell proliferation. It is the prototype for the study of growth factors.

Answer 35

Epidermal growth factor (EGF)

Question 36

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

Answer 36

cytokines

Question 37

___ ___, ___, and ___ ___ CANNOT cross the plasma membranes of target cells, so they act by binding to cell surface receptors.

Answer 37

peptide hormones, neuropeptides, growth factors

Question 38

___: lipid signaling molecules that include prostaglandins, prostacyclin, thromboxanes, and leukotrienes.

They break down rapidly, acting in autocrine or paracrine pathways.

Answer 38

Eicosanoids

Question 39

Eicosanoids are synthesized from arachidonic acid which is converted to prostaglandin H2, catalyzed by ___.

Answer 39

COX

Question 40

The enzyme COX is the target of ___, and other NSAIDs.

Answer 40

aspirin