Basic Metabolism

Question 1

In solution, glucose forms a 6-membered ring structure. This is called x. 5-membered rings are called y.

Answer 1

Pyranose, furanose

Question 2

What is the normal fasting concentration of glucose? What does this rise to after a meal?

Answer 2

Around 4 mM, rises to around 8mM

Question 3

Name two glucose-dependent cell types.

Answer 3

Brain and erythrocytes

Question 4

Why is the brain glucose-dependent?

Answer 4

Fatty acids can’t cross the blood brain barrier (bound to albumin), so the brain relies completely on glucose for aerobic respiration.

Question 5

Why are erythrocytes glucose-dependent?

Answer 5

Erythrocytes don’t have mitochondria so use glucose in glycolysis to obtain ATP.

Question 6

How are oligosaccharides digested to disaccharides?

Answer 6

Pancreatic amylase hydrolyses GCBs in oligosaccharide

Question 7

How are disaccharides digested to monosaccharides?

Answer 7

Membrane-bound disaccharidases in the mucosal cells lining the gut hydrolyse GCBs in disaccharides

Question 8

Insulin increases the expression of GLUT4 in which tissues?

Answer 8

Skeletal muscle, adipose, heart

Question 9

Insulin increases the expression of GLUT3 in which tissue?

Answer 9

Brain

Question 10

Insulin increases the expression of GLUT2 in which tissues?

Answer 10

Liver, kidney, pancreas, B-cells

Question 11

Insulin increases the expression of GLUT1 in which cells?

Answer 11

Erythrocytes