Hormones

Question 1

4 types of hormones & e.g.

Answer 1

1. AA derivatives e.g. T3 & T4
2. Polypeptide e.g. Insulin & glucagon
3. Steroids e.g. testosterone & oestreogen
4. biologically potent e.g. nitric oxide for vasodilation

Question 2

3 effects of insulin in response to Hi [glu]

Answer 2

• glucose uptake in muscle
• glycogen synthesis in liver
• glycerol synthesis in adipocytes

Question 3

insulin is made by preproinsulin -> proinsulin -> mature insulin. what are the component in these?

Answer 3

1. prepro: Chain A + B + C + signal sequence
2. pro: Chain A + B + C
3. insulin: Chain A + B

Question 4

Fast acting insulin has a [Hi/Lo] MW. Whereas long acting insulin has [Hi/Lo] MW

Answer 4

low

High

Question 5

which hormone inhibits insulin release?

which hormone inhibits glucagon release?

Answer 5

a. somatostatin

b. somatostatin & insulin

Question 6

how does insulin activate the receptor in target cells?

Answer 6

1. Insulin binds to receptor, composed of 2 alpha & 2 beta units
2. Autophosphorylation occurs: tyrosine Kinase add P group to Insulin receptor substrate 1 (IRS-1)
3. Activated IRS-1 combines to other molecules => activating them in a cascade

Question 7

Glucose uptake is promoted by insulin in most tissues EXCEPT:

Answer 7

brain & liver bc doesn’t use GLUT4 for importing glucose (GLUT4 activated by insulin)