Signal Transduction

Question 1

Mechanisms of intracellular signaling

Answer 1

Small hydrophobic molecule brought in by carrier/binding protein and binds to cytosolic receptor inside cell; nuclear receptor binds to TFs

Question 2

Types of hormones that utilize intracellular signaling

Answer 2

Steroid, thyroid, retinoic acid, and vit D

Question 3

Response element

Answer 3

Area of DNA that TF binds to

Question 4

Co-activators

Answer 4

Encourage transcription

Question 5

Tyrosine kinase receptor signaling for receptors that activate a monomeric G protein

Answer 5

1. ) Dimerization to activate it
2. ) Autophosphorylation to fully activate and draw in receptor proteins
3. ) Binding of adaptor proteins
4. ) Complex assembly
5. ) GEF exchanges GDP for GTP and activates Ras
6. ) Ras binds Raf and initiates MAP Kinase pathway

Question 6

GEF

Answer 6

catalyzes GTP>GDP on Ras

Question 7

Ras activates…

Answer 7

MAP Kinase pathway

Question 8

PI Pathway

Answer 8

PLC generates DAG (remains with membrane and activates PKC) and IP3 (triggers Ca release from SR) while PI3-kinase generates PIP3 which docks certain proteins to the membrane

Question 9

Jak-STAT

Answer 9

1. ) Dimerization
2. ) Autophosphorylation
3. ) Receptor binds and phosphorylates STATs
4. ) STATs dissociate from receptor, dimerize, and translocate to nucleus where they work on transcription

Question 10

Adaptor proteins

Answer 10

Have protein-binding molecules that link protein-binding cohorts together and create larger signaling complexes; allows cell signals to be propagated and elicit a specific response to external stimuli

Question 11

Serine threonine kinase

Answer 11

1. ) Ligand binds to type II receptor
2. ) Type II receptor phosphorylates type I receptor
3. ) Activated type I phosphorylates R-Smad
4. ) R-Smad complexes with Co-Smad and migrates to nucleus

Question 12

GPCR general mechanism

Answer 12

1. ) receptor binds hormone
2. ) G protein exchanges GDP>GTP and dissociates
3. ) target protein binds GTP-Galpha

Question 13

Galphas

Answer 13

1. ) Target protein is adeylyl cyclase
2. ) Converts ATP>cAMP
3. ) cAMP activates PKA
4. ) Catalytic subunit of PKA dissociates and phosphorylates proteins
5. ) phosphorylation cascade

Question 14

Galphaq

Answer 14

1. ) Target protein is PLC
2. ) Activates phosphotidylinositol pathway
3. ) PLC creates DAG and IP3
4. ) DAG activates PKC and starts a phosphorylation cascade
5. ) IP3 triggers release of Ca from ER