Signaling And Transport

Question 1

Primary Active transport

Answer 1

Uses energy derived directly from ATP hydrolysis

Question 2

Name the cell signaling pathway: when 2 singles have opposite effects on a metabolic characteristic, the regulatory outcome results from the integrated input from both. (Multiple signals, one outcome)

Answer 2

Integration

Question 3

Name the cell signaling pathway: proteins with multivalent affinities form diverse signaling complexes from interchangeable parts. (Phosphorylation provides reversible points of interaction)
One signal, many possible outcomes.

Answer 3

Modularity.

Question 4

Target effect of G-protein coupled receptor:

Answer 4

Breakdown of glycogen and increase blood glucose levels

Question 5

Secondary active transport

Answer 5

Uses energy derived secondarily that has been stored in the form of ionic concentration differences between two sides of a membrane

Question 7

Cytoplasmic events of G-protein coupled receptor:

Answer 7

cAMP binds regulatory subunit PKA.

This releases PKA catalytic subunit to phosphorylation other proteins that activate metabolic enzymes.

Question 8

Name the cell signaling pathway: when enzymes activate enzymes, the number of affected molecules increases geometrically in enzyme cascades.

Answer 8

Amplification

Question 9

Ligand of gated ion channel:

Answer 9

Acetylcholine

Question 10

What do ion selective channels do?

Answer 10

They allow for rapid movement of ions across membranes. (In neurons, this causes action potentials)

Question 11

Passive transport

Answer 11

Requires no energy input to work

Question 11

What is the three main differences between ion channels and ion transporters?

Answer 11

1. Flux rate through channels is orders of magnitude greater than through transporters.
2. Ion channels aren’t saturable. Rates do not approach their max at high substrate concentrations.
3. Channels are gated in response to some cellular event, like ligand gated or ion gated channels.

Question 14

Name the cell signaling pathway: receptor activation triggers a feedback circuit that shuts off the receptor, or removes is from the cell surface.

Answer 14

Desensitization/Adaption

Question 15

Membrane events of G-protein coupled receptor:

Answer 15

Adenylate Cyclase activation
ATP—>cAMP
GDP—>GTP

Question 16

What do ion gradients do?

Answer 16

Provide energy for secondary active transport.

Question 17

Name the cell signaling pathway: signal molecules fit binding site on complementary receptor, other signals do not.

Answer 17

Specificity

Question 18

What is an ABC transporter?

Answer 18

A family of ATP transporters that pump amino acids, peptides, proteins, ions, etc… AGAINST the concentration gradient

Question 18

Ligand of G-protein coupled receptor:

Answer 18

Adrenaline, norepinephrine

Question 20

Receptor of G-protein coupled receptor:

Answer 20

Beta-andrenergic receptor

Question 20

Second messenger of G-protein coupled receptor:

Answer 20

cAMP

Question 21

Name the cell signaling pathway: when the enzyme that destroys an intracellular message is clustered with the message producer, the message is degraded before it can diffuse to distant points, so the response is only local and brief.

Answer 21

Localized response

Question 22

Ligand of receptor enzymes:

Answer 22

Insulin

Question 23

Membrane events of nuclear hormone receptor:

Answer 23

Estrogen diffuses through membrane

Question 24

Receptor of receptor enzymes:

Answer 24

RTK (Receptor Tyrosine Kinase) / insulin receptor

Question 25

Membrane events of receptor enzymes:

Answer 25

Autophosphorylation of intracellular tyrosine kinase receptor domains of insulin receptor

Question 27

Cytoplasmic events of receptor enzymes:

Answer 27

Insulin receptor phosphorylates IRS1. Initiates binding of other proteins. Ras exchanges GDP for GTP, and binds and activates RAF1. RAF1 phosphorylates MEK which phosphorylates ERK which translocates into nucleus and phosphorylates transcription factors.

Question 27

Target response of receptor enzymes:

Answer 27

Regulation of gene transcription of genes related to cell proliferation

Question 27

Receptor of gated ion channel:

Answer 27

Acetylcholine receptor

Question 29

Second messenger of receptor enzymes:

Answer 29

None

Question 30

Membrane events of gated ion channel:

Answer 30

Channel allows cation passage

Question 31

Target effect of nuclear hormone receptor:

Answer 31

Regulation of transcription of genes related to cell proliferation

Question 32

Second messenger of gated ion channel:

Answer 32

None (ionotropic)

Question 33

Cytoplasmic events of gated ion channel:

Answer 33

Cell depolarization

Question 35

Ligand of nuclear hormone receptor

Answer 35

Estrogen

Question 35

Receptor of nuclear hormone receptor:

Answer 35

Estrogen receptor

Question 35

Second messenger of nuclear hormone receptor:

Answer 35

None

Question 37

Target effect of gated ion channel:

Answer 37

Neurotransmission

Question 37

Cytoplasmic events of nuclear hormone receptor:

Answer 37

Estrogen binds receptor:Hsp70 complex, causing Hsp70 to dissociate and the receptor to dimerize.
Estrogen:receptor complex translocates through nuclear membrane and binds to specific regulatory DNA sequences.