Chapter 4 Study Questions (Part 3)

Question 1

what role do pancreatic beta cells play in insulin secretion?

Answer 1

make insulin. insulin is stored in a vesicle

Question 2

why do we release insulin?

Answer 2

in response to hyperglycemia

Question 3

what role do glucose transporters on beta cells play in insulin secretion?

Answer 3

bring glucose into the cell

Question 4

what role do ADP/ATP-gated K+ channels play in insulin secretion?

what happens when glucose inside cells is high?

Answer 4

release K+. when glucose inside the cell is high, there’s lots of ATP, so this channel is closed. that means they retain K+ and the inside becomes more positive

Question 5

what role do voltage-gated Ca+2 channels play in insulin secretion?

aka what are they activated by and what happens ?

Answer 5

activated by high levels of potassium and lots of calcium enters

Question 6

what role does calmodulin play in insulin secretion?

Answer 6

activated by calcium. it’s a protein that activates a kinase that changes the tethering protein function and causes it to let go of the vesicle.

Question 7

what role do motor proteins play in insulin secretion?

Answer 7

grab the vesicle, and walk down microtubules towards the plasma membrane

Question 8

what role do microtubules play in insulin secretion?

Answer 8

lead motor protein with vesicle to fuse with the membrane and release kinase. target of phophorylation