31. Glycolysis

Question 1

How does glucose enter cells?

Answer 1

Facilitated diffusion using GLUT transport proteins

Na+ dependent co-transport

Question 2

How is glucose prevented from leaving the cell?

Answer 2

Trapped by phosphorylation

Question 3

What is the function of hexokinase?

Answer 3

Allows glucose to enter cells even when fasting

Question 4

What is hexokinase regulated by?

Answer 4

glucose-6-phosphate

Question 5

What is the function of glucokinase?

Answer 5

Minimises uptake of glucose while fasting

Prevents unnecessary synthesis of glycogen

Question 6

What is glucokinase regulated by?

Answer 6

Glucose

GkRP

Question 7

What is phosphofructokinase 1 inhibited by?

Answer 7

ATP

Question 8

What is glucokinase inhibited by?

Answer 8

Fructose-6-phosphate

Question 9

What is phosphofructokinase 1 activated by?

Answer 9

Fructose-2,6-biphosphate

Question 10

What controls phosphofructokinase 2 activity?

Answer 10

Insulin

Glucagon

Question 11

How does pyruvate enter mitrochondria?

Answer 11

Pyruvate transporter in inner mitochondrial membrane

Pyruvate dehydrogenase complex converts pyruvate to acetyl CoA

Question 12

What is the pyruvate dehydrogenase complex made up of?

Answer 12

3 enzymes

5 co-enzymes

Question 13

What are the metabolic fates of pyruvate?

Answer 13

Acetyl Co-A: enters TCA
Oxaloacetate: enter TCA
Reduction to ethanol

Question 14

What is pyruvate dehydrogenase deficiency?

Answer 14

X-linked
Congenital lactic acidosis
Developmental defects
Muscular spasticity
Early death

Question 15

How does arsenic poisoning disrupt glycolysis?

Answer 15

Inhibits pyruvate dehydrogenase

Question 16

Deficiency in which vitamins impairs pyruvate dehydrogenase function?

Answer 16

B1,2,3,5

Question 17

Name the intermediates in glycolysis

Answer 17

Glucose-6-phosphate
Fructose-6-phosphate
Fructose-1,6-biphosphate
Glyceraldehyde-3-phosphate
1,3-biphosphoglycerate
3-phosphoglycerate
Pyruvate