Glucose

Question 1

What is the monomer of a sugar called?

Answer 1

Monosaccharide

Question 2

What are the three structures of glucose?

Answer 2

Aldose sugar (Carbonyl group at C6)
1) Straight chain, least common at about 1% abundance
2) Pyranose ring (5C ring), α-D-glucopyranose anomer , which is second most common structure at 36%
3) Pyranose ring (5C chain), β-D-glucopyranose anomer, most abundant at 64% abundancy.
Only difference between 2 and 3 is the rotation of substituents of C1

Question 3

What are the five different types of glucose transporters and where are they found in the body?

Answer 3

Glucose transporters are membrane-bound proteins. Not fully opened so binds glucose then changes conformation to let it move through.
GLUT1: Found in all mammalian tissues with a km[glucose]=1mM(High affinity of enzyme binding substrate). It’s used for basal glucose uptake.
GLUT2: Found in Liver and pancreatic β cells, has km=15-20mM. It regulates insulin in the pancreas, and removes excess glucose from the blood in the liver
GLUT3: This is found in the brain and has a km=1mM (glucose is the brains main source of energy, needs to have high affinity), This glucose transporter is for basal glucose uptake in the brain.
GLUT4: Present in muscle and fat cells, km=5mM. Used in muscle and adipose tissue to increase glucose uptake when insulin is signalling.
GLUT5: Present in small intestine and is primarily a fructose transporter.

Question 4

What is the polysaccharide of glucose units called?

Answer 4

glycoside