Gluconeogenesis

Question 1

Gluconeogenesis definition

Answer 1

synthesis of glucose from non-carb precursors, occurs in the liver and a little bit in kindeys

Question 2

what non-carb precursors can gluconeogenesis use?

Answer 2

lactate, pyruvate, oxaloacetate, amino acids, and glycerol

Question 3

4 main functions of gluconeogenesis

Answer 3

1. provides glucose when not enough dietary intake
2. control of acid-base balance
3. maintenance of AA balance
4. provision of biosynthetic precursors

Question 4

what is the reverse of glycolysis?

Answer 4

gluconeogenesis

Question 5

1st part of step 1 of gluconeogenesis

Answer 5

pyruvate is transported to mitochondria and converted to oxaloacetate
- uses enzyme pyruvate carboxylase

Question 6

2nd part of step 1 of gluconeogenesis

Answer 6

oxaloacetate (OAA) is transported back to the cytosol (transported as malate) and reconverted to OAA
- OAA converted to phosphoenolpyruvate (PEP)
-uses enzyme PEPCK (PEP carboxykinase)

Question 7

F 1,6-BP to F 6-P

Answer 7

• bypasses phosphofructokinase-1 in glycolysis, bc the reverse rxn isn’t favorable
• regulatory step, stimulated by high ATP, uses enzyme fructose 1,6-biphosphatase

Question 8

G 6-P to glucose

Answer 8

• uses glucose 6-phosphatase
• only occurs in the liver kidney, and small intestine, using integral membrane protein in smooth ER

Question 9

gluconeogenesis results

Answer 9

2 pyruvate to glucose=
- 6 ATP equivalents
- 2 NADH molecules (oxidized to NAD+)

Question 10

does gluconeogenesis happen in high or low ATP levels

Answer 10

high ATP