Signal Transduction

Question 1

steroid hormones

Answer 1

intracellular receptors, lipophilic, can pass through membrane unaided
FOUND IN CYTOPLASM

Question 2

cell surface receptors

Answer 2

embedded in plasma membrane of cell and face extracellular space

Question 3

intracellular/ nuclear receptors

Answer 3

found in cytoplasm/ nucleus, bind to membrane-soluble ligands

Question 4

contact dependent

Answer 4

requires physical contact of the two cells

Question 5

endocrine system

Answer 5

signal producing cells release signaling molecules that act on taget cells

Question 6

paracrine

Answer 6

signal producing cells release signaling molecules that act on proximal target cells

Question 7

synaptic

Answer 7

neurotransmitter signaling @ synapses

Question 8

phosphorylation=

Answer 8

on

Question 9

dephosphorylation=

Answer 9

off

Question 10

receptor tyrosine kinases

Answer 10

largest class of enzyme coupled receptors
most extracellular signals for growth, survival, and proliferation

Question 11

SH2 domain

Answer 11

recognizes phosphorylated tyrosines
bind phosphorylated tyrosines

Question 12

general mechanism enzyme coupled receptors

Answer 12

ligand binds, bringing subunits together=dimerization
-leads to phosphorylation of tyrosines on RTK

Question 13

GTP

Answer 13

on

Question 14

GDP

Answer 14

off

Question 15

phosphorylated PKB

Answer 15

increases glcose uptake and glycogen synthesis

Question 16

RTKs activating PI3

Answer 16

induces protein synthesis to regulate glucose transport and glycogen synthesis
-PI3 activated instead of RAS

Question 17

receptor serine/threonine kinases

Answer 17

TGF-B binds, dimerization/ phosphorylation occurs
-SMAD complex moves to nucleus and regulates gene expression
-SMAD is mediator !!

Question 18

cytokine receptors

Answer 18

DO NOT HAVE INTRINSIC KINASE ACTIVITY
associated w JAK kinase
receptors for signaling molecules that control growth and differentiation of leukocytes

Question 19

JAK

Answer 19

tyrosine kinase, recruits STAT

Question 20

STAT

Answer 20

mediator of signal for cytokine receptors

Question 21

TNF receptors inactive when

Answer 21

if ligand absent, Ikb binds NFKb= inactive

Question 22

thyroid hormones

Answer 22

FOUND IN NUCLEUS

Question 23

An inhibitor of RAF would prevent the activation of what molecule

Answer 23

MEK