Chapter 16: Glycolysis and Gluconeogenesis

Question 1

Where does glycolysis take place in the cell?

Answer 1

The cytoplasm

Question 2

At which points in glycolysis is it regulated and how?

Answer 2

Allosterically regulated (mostly) at:

1) Hexokinase
2) Phosphofructokinase (most important regulator)
3) Pyruvate Kinase

Question 3

When does gluconeogenesis happen?

Answer 3

Answer:

Question 4

Which are the committed steps in glycolysis?

Answer 4

1) Conversion of glucose to glucose 6-phosphate
2) Conversion of Fructose 6-phosphate to Fructose 1,6-bisphosphate
3) Conversion of phosphoenolpyruvate to pyruvate

Question 5

Which are the committed steps in gluconeogenesis?

Answer 5

1) Conversion of pyruvate to oxaloacetate
2) Conversion of Fructose 1,6-bisphosphate to Fructose 6-phosphate
3) conversion of glucose 6-phosphate to glucose

Question 6

Talk out (or draw) the process of glycolysis.

Answer 6

Answer:

Question 7

Talk out (or draw) the process of gluconeogenesis.

Answer 7

Answer:

Question 8

What is the purpose of glycolysis?

Answer 8

Answer:

Question 9

How is glycolysis in the liver different from glycolysis in the muscles?

Answer 9

Answer:

Question 10

At which points is gluconeogenesis regulated and how?

Answer 10

1) pyruvate carboxylase
2) phosphoenolpyruvate carboxykinase
3) fructose 1,6-bisphosphatase

Question 11

Which products of glycolysis are used by other processes and for which processes?

Answer 11

Answer:

Question 12

Which products of gluconeogenesis are used by other process and for which processes?

Answer 12

Answer:

Question 13

How is phosphofructokinase regulated? How is regulation different in the muscle in comparison to the liver?

Answer 13

Inhibited by: 
-ATP 
-low pH (more common in muscle), 
-Citrate (in liver)
Activated by:
-AMP
-Fructose 2,6-bisphosphate (liver)

Question 14

How is Hexokinase regulated? How is regulation different in the muscle in comparison to the liver?

Answer 14

Inhibited by:
-glucose 6-phosphate
no difference between liver and muscle

Question 15

How is pyruvate kinase regulated? How is regulation different in the muscle in comparison to the liver?

Answer 15

Inhibited by:
-ATP
-Alanine (liver)
-Glucagon triggered cAMP cascade (hormone based regulation, in liver)
Activated by:
-Fructose 1,6-bisphosphate

Question 16

How is pyruvate carboxylase regulated?

Answer 16

Inhibits: ADP
Activates: acetyl CoA

Question 17

How is phosphoenolpyruvate carboxykinase regulated?

Answer 17

Inhibits: ADP

Question 18

How is fructose 1,6 bisphosphatase regulated?

Answer 18

inhibits:
-Fructose-2,6-bisphosphate
-AMP
Activates:
-Citrate