Bioenergetics lecture 6: Gluconeogenesis

Question 1

What is gluconeogenesis. What does it require

Answer 1

Generation of glucose from other organic molecules. This requires investment of ATP and NADH

Question 2

Where does gluconeogenesis take place

Answer 2

In liver mostly and kidney.

Question 3

What are the two ways that Gluconeogenesis and glycolysis are regulated

Answer 3

1. Local allosteric control depending on the cells specific energy needs
2. Global control (through circulating hormones that activate cellular signalling cascades that override the local conditions.)

Question 4

What is gluconeogenesis. What does it require

Answer 4

Generation of glucose from other organic molecules (pyruvate, lactate, glycerol, amino acids). This requires investment of ATP and NADH

Question 5

Where does gluconeogenesis take place

Answer 5

In liver mostly and kidney. Not skeletal muscle

Question 6

What are the two ways that Gluconeogenesis and glycolysis are regulated

Answer 6

1. Local allosteric control depending on the cells specific energy needs
2. Global control (through circulating hormones that activate cellular signalling cascades that override the local conditions.)

Question 7

Gluconeogenesis is backwards glycolysis. How does it overcome the 3 irreversible steps

Answer 7

1. Bypass 1 uses Pyruvate carboxylase and PEPCK
2. Fructose-1,6-Biphosphatase
3. Glucose-6-phosphatase

Question 8

Bypass 1

Answer 8

Pyruvate gets converted to Oxaloacetate which involves ATP investment by pyr

Question 9

Gluconeogenesis is backwards glycolysis. What 3 enzymes does it use to bypass the 3 irreversible steps

Answer 9

1. Bypass 1 uses Pyruvate carboxylase and PEPCK
2. Fructose-1,6-Biphosphatase
3. Glucose-6-phosphatase

Question 10

How does bypass 1 work

Answer 10

Pyruvate gets converted to Oxaloacetate (ATP) this goes through the irreversible step using NADH to become Malate. This Malate is then exported out of the mitochondria and then becomes oxaloacetate using an NADH and then PEPCK invests GTP to make it Phosphoenolpyruvate.