Lecture 15- Glycolysis

Question 1

Glucose transporters (GLUT’s)

Answer 1

Makes sure the cell takes in glucose, located on cell membrane, how glucose uptake occurs

Question 2

GLUT1

Answer 2

Located: Ubiquitous RBC’s, brain, cornea, placenta, and cx cells

• Unregulated
• High affinity (Km=1 mM)

Question 3

GLUT2

Answer 3

Located: Liver and pancreas

• Unregulated
• Low affinity (Km=10 mM)

Question 4

GLUT3

Answer 4

Located: Neurons

• Unregulated
• High affinity (Km=1 mM)

Question 5

GLUT4

Answer 5

Located: skeletal muscle, adipose tissue, and heart

• Regulated by insulin**
• High affinity (Km=5 mM)

Question 6

First stage of glycolysis

Answer 6

Trapping of glucose and its cleavage into 2 interconvertible 3-carbon molecules

Question 7

Second stage of glycolysis

Answer 7

Generation of ATP

Question 8

First stage of glycolysis starts and ends with what?

Answer 8

Starts: Phosphorylation of glucose
Ends: Isomerization of dihydroxyacetone phosphate to glyceraldehyde 3-phosphate (GAP)

Question 9

What traps glucose?

Answer 9

Hexokinase

Question 10

What is the first committed step?

Answer 10

PFK1 (Phosphofructokinase)

Question 11

Three major regulatory enzymes of glycolysis

Answer 11

1. Hexokinase
2. Phosphofructokinase (PFK1)
3. Pyruvate kinase