MCM test 1

Question 1

scurvy

Answer 1

• defective collagen formation
• vit C deficiency:propyl hydroxylase
• impaired wound healing, capillary hemorhage, deficient platelet, osteoblast, osteoclast function

Question 2

What does anti-microtubule chemotherapy do?

Answer 2

• inhibits poly/depolymerization
• microtubules stable/nonfunctional=no mitosis
• taxanes, vinca alkaloids, colchcine

Question 3

how do cells specialize?

Answer 3

expression of receptors

Question 4

trophic factors

Answer 4

signals that keep cells alive, absence=death

Question 5

what do responding cells depend on?

Answer 5

position w/n the gradient

Question 6

what do mitogens do?

Answer 6

activates G1/S-Cdk to stimulate cell division

Question 7

endocrine

Answer 7

distant sites

Question 8

paracrine

Answer 8

nearby cells

Question 9

what signals activate intracellular receptors?

Answer 9

steroids/NO

Question 10

Where and how do steroids act?

Answer 10

form dimers and act on nuclear receptors, act as transcription factors and change gene expression directly

Question 11

How is NO made?

Answer 11

NO synthase from arginine

Question 12

Where and how does NO act?

Answer 12

only locally, acts on guanylyl cyclase which produces cGMP and nitrosylates residues on some proteins

Question 13

peptide hormones

Answer 13

long half life and distant acting includes GH and neuropeptides

Question 14

What is the effector mechanism of neurotransmitters?

Answer 14

• ligand-gated ion channels-change ion conc-AP

- G-protein coupled-indirectly regulate ion channels

Question 15

Eicosanoids

Answer 15

lipids, act locally w/ short half life, induce clotting and inflammation

Question 16

How are eicosanoids synthesized?

Answer 16

phospholipase A2(phospholipids->arachdonic acid)->COX(arachdonic acid->prostaglandins)

Question 17

What do NSAIDS and aspirin inhibit?

Answer 17

COX1/2

Question 18

What are the ligands for ion-channel-coupled receptors?

Answer 18

neurotransmitters

Question 19

How do GPCR’s bind G proteins?

Answer 19

a binds GTP, By subunits bind the receptor and a subunit

Question 20

What are the ligands for GPCR’s?

Answer 20

eicosanoids, NT’s, and peptide hormones

Question 21

What receptors are responsibe for smell, sight, and taste?

Answer 21

GPCR’s

Question 22

describe the activation of GPCR’s

Answer 22

ligand binds, GDP exchanged for GTP by GEF’s, a subunit dissociates, By subunit dissacociates and then they act on intracellular targets

Question 23

How are GPCR’s deactivated?

Answer 23

GAP’s hydrolzye GTP to GDP

Question 24

What are the ligands for Receptor Tyrosine Kinases(RTK’s)?

Answer 24

growth factors and membrane bound ligands

Question 25

What is special about RTK's?

Answer 25

have and intrinsically bound tyrosine kinase domain

Question 26

What are soluble RTK's associated with the plasma membrane activated by?

Answer 26

TKAR's (Tyrosine kinase associated receptors)

Question 27

What do cytokine receptors signal through?

Answer 27

Jak Stat

Question 28

what ligand activates receptor serine/threonine kinases and what pathway does that activate?

Answer 28

TGF-B, SMAD pathway

Question 29

What is the ligand for Notch?

Answer 29

delta

Question 30

what is the ligand for Frizzled?

Answer 30

Wnt

Question 31

What is the ligand for Patched?

Answer 31

Hedgehog

Question 32

adenylyl cyclase

Answer 32

forms cAMP from ATP

Question 33

cAMP phosphodiesterase

Answer 33

degrades cAMP to AMP

Question 34

What is the action of cAMP?

Answer 34

binds to the regulatory subunit of Protein Kinase A, causing it to dissociate and phosphorylate targets

Question 35

What is the action of cGMP?

Answer 35

activates protein kinases, ion channels, and phosphodiesterases