Signal Transduction Flashcards Preview

Biochem block 3 > Signal Transduction > Flashcards

Flashcards in Signal Transduction Deck (16):
1

what are intracellular signal?

signal that come from WITHIN the cell

2

what are intercellular signals?

responses to extracellular signals to coordinate metabolic activities

3

what are the 3 characteristics of G-protein coupled receptors (GPCR)?

1. extracellular ligand binding domain
2. 7 transmembrane spanning domains
3. intercellular G-protein activation domain

4

does G-protein stimulate or inhibit adenylyl cyclase?

either depending on the receptor (GPCR)

5

What are the three things that protein kinase A catalytic subunits can phosphorylate?

DNA binding proteins
ion channels
enzymes

6

what are the 2 enzymes that can stop the signal transduction pathway?

protein phosphatases
cAMP phosphodiesterase

7

Calcium binds to ________ in the liver to activate enzymes and initiate metabolism?

Calmodulin

8

what factors negatively affect insulin secretion?

increased epinephrine
decreased dietary fuels

9

what causes the secretion of epinephrine?

stress
trauma
extreme exercise

10

what factors positively affect insulin?

amino acids
glucose

11

What is the enzyme that insulin activates?

Tyrosine kinase

12

What does tyrosine kinase phosphorylate?

IRS

13

Glucagon secretion is stimulated by?

Increasing epinephrine levels
Increasing amino acid levels

14

Glucagon is inhibited by?

Increasing glucose and insulin levels

15

What is the blood glucose level of hypoglycemia?

< or = 70 mg/dl

16

What are the 3 types of hypoglycemia?

Postprandial
Insulin induced
Fasting