Chemistry

Question 1

Glycolysis and GNG rate limiting steps

Answer 1

Gly - phosphofructokinase

GNG - fructose 1,6 biphosphatase

Question 2

TCA cycle rate limiting steps

Answer 2

Isocitrate dehydrogenase

Question 3

Glycogen synthesis and glycogenolysis rate limiting steps

Answer 3

synthesis - glycogen synthase

lysis - glycogen phosphorylase

Question 4

HMP shunt rate limiting steps

Answer 4

glucose-6-phosphate dehydrogenase

Question 5

Urea cycle rate limiting step

Answer 5

Carbamoyl phosphate synthetase

Question 6

Fatty acid synthesis and oxidation rate limiting steps

Answer 6

Synthesis: Acetyl-CoA carboxylase
Oxidation: Carnitine acyltransferase

Question 7

Cholesterol synthesis rate limiting step

Answer 7

HMG-CoA reducatase

Question 8

Starch

Answer 8

Polysaccharide carbohydrate with glucose monosaccharides joined with glycosidic bonds

Amylose: long, unbranched glucose chains linked with a1,4 bonds
Amylopectin: highly branched glucose polymer. Glucose linked linearly with a 1,4 bonds. Branching with a1,6 bonds every 24-30 glucose units

Question 9

Sucrose

Answer 9

Disaccharide made of glucose and fructose. Table sugar and fruits

Question 10

Lactose

Answer 10

Found in milk. Galactose linked to glucose. humans can only digest the sugars with D conformation (right-handed)

Question 11

Cellulose

Answer 11

Polysaccharide. linear chain of several hundred to thousand beta 1,4 linked D glucose units
Indigestible by humans because we lack cellulase

Question 12

Glucose transporters GLUT 1-4

Answer 12

G1: Red blood cells, brain, placenta, testis
G2: Beta cells in the pancreas
G3: Neurons
G4: Adipose cells, skeletal and cardiac muscle

Question 13

Glycolysis

Answer 13

one 6 carbon glucose is broken down to 2 3 carbon pyruvates
Net yield: 2 ATP, 2 NADH for each glucose molecule

Anaerobic, 2 phase - 10 step process