Lecture 4, carbohydrate storage

Question 1

· Describe the purpose of gluconeogenesis, and from which molecule it starts

Answer 1

The purpose of gluconeogenesis is to convert molecules such as lactate, pyruvate, glycerol, amino acids and intermediates of the TKA cycle into glucose. Gluconeogenesis is important since the brain requires 20g of glucose every day and it’s important this energy need can be met.

Question 2

· Describe how and where carbohydrates are stored in animals

Answer 2

Carbohydrates are stored in the liver as glycogen.

Question 3

· Name some allosteric regulators of gluconeogenesis

Answer 3

Glucose 6 phostphatase, Fructose 1,6-biphostphatase, pyruvate carboxynalase

Question 4

· Name the key enzymes in glycogenolysis and what they do

Answer 4

Glycolysis goes from glucose to pyruvate, for when the body needs to acces stored energy. Important enzymes are hexokinase that phosrphorylates the sugar molecule, phosphofructokinase-1 catalyze the irreversible step of turning fructose 6-phstphate to fructose 1,6-biphostphate and pyruvate kinase catalyze the transfer of a phostphate group in the last steps of glycolysis.

Question 5

· Name the key enzymes in gluconeogenesis and what they do

Answer 5

Pyruvate turns into glucose witht the key enzymes pyruvate carboxylase, fructose 1,6 biphostphatase that turns into fructose 6-phostphatase and glucose 6 phostphatase into glucose