Cellular signaling

Question 1

signal transduction

Answer 1

conversion of one type of signal into another type

Question 2

Steroids

Answer 2

Hydrophobic ligands whose receptors are also transcription factors that turn on after steroids bind to them

Question 3

response to ligands

Answer 3

Initial response to ligands is similar between cells and response can be sorted into different types of responses. Different cells can have different reactions to the same signal molecule.

Question 4

Signal receptors are ____

Answer 4

bifunctional. They bind the ligand and transduce signals.

Question 5

RTK binding process

Answer 5

1. ) Signal molecule binds to extracellular domain and forces it to dimerize
2. ) Tyrosine kinase is activated and phosphorylates
3. ) Intracelullar signaling proteins bind to phosphotyrosines

Question 6

Adaptor proteins

Answer 6

contain SH2 domains that allow intracellular signaling molecules to bind to phosphotyrine

Question 7

benefits of cascade complexity

Answer 7

• signals can be amplified

- multiple steps available for process to be regulated

Question 8

Intracellular signaling proteins –> ? –> change in protein activity

Answer 8

1. ) Ras is activated
2. ) Ras stimulates MAP kinase cascade
3. ) MAP kinase cascade uses ATP and changes protein activity

Question 9

G protein

Answer 9

can activate phospholipase C and adenylyl cyclase

Question 10

DAG

Answer 10

activates protein kinase C which phosphorylates various proteins

Question 11

phospholipase C

Answer 11

cleaves PIP2 into DAG and IP3

Question 12

IP3

Answer 12

Opens calcium channel in ER, letting calcium bind to and activate calmodulin
hydrophobic

Question 13

adenylyl cyclase

Answer 13

synthesizes cyclic AMP (cAMP) from ATP

Question 14

cAMP

Answer 14

cyclic AMP activates protein kinase A which phosphorylates target proteins