Diabetes

Question 1

What are the steps in insulin production?

Answer 1

1. N terminal sequence is cleaved from preproinsulin to make proinsulin.
2. C-peptide is cleaved from proinsulin –> insulin.

Question 2

1. Preproinsulin has __ disulfide bonds.
2. Prosinsulin has __ disulfide bonds.
3. Insulin has __ disulfide bonds.

Answer 2

1. 0
2. 2
3. 2

Question 3

How is beta cell insulin secretion stimulated?

Answer 3

1. Glucose enters cell —> ATP.
2. ATP causes closing of K+ channel –> membrane depolarization.
3. Ca2+ channel opens, insulin is released.
   OR
   GLP-1 binds GLP-1 R, activates cAMP, activates PKA, K+ channel closes…

Question 4

What are GLP1 and GIP?

Answer 4

Hormones released from the GI cells that act on beta cells in pancreas to release insulin

Question 5

What are Extenatide and Januvia (sitagliptin)?

Answer 5

Extenatide is a GLP1 analogue that stimulates insulin secretion.
Januvia blocks the DPPIV protease that degrades GLP1 to promote insulin secretion.

Question 6

What causes Type I diabetes?

Answer 6

Type IV immune attack against pancreatic beta cells

Question 7

Ketoacidosis is more common amongst Type __ diabetics.

Answer 7

I

Question 8

What is IRS-1?

Answer 8

A thing bound to insulin receptor (cytoplasmic side) that promotes dephosphorylation after binding of insulin.

Question 9

Name the three reasons why glucose levels are so elevated in diabetics.

Answer 9

1. No cellular glucose intake
2. Increased glycogen breakdown
3. Increased gluconeogenesis

Question 10

What does metformin do?

Answer 10

Blocks gluconeogenesis.

Question 11

What does insulin do to LPL?

Answer 11

Activates