Gluconeogenesis

Question 1

Main site of gluconeogenesis during an overnight fast

Answer 1

Liver

Question 2

Main site of gluconeogenesis during prolonged fasting

Answer 2

Kidneys

Question 3

Cori’s cycle is one where ___ is converted to pyruvate to enter the gluconeogenesis pathway

Answer 3

Lactate

Question 4

Predominant AA transported to the liver from muscle proteolysis during periods of starvation

Answer 4

Alanine

Question 5

Formed when aspartate undergoes transamination via aspartate aminotransferase with a-ketoglutarate

Answer 5

Oxaloacetate

Question 6

All amino acids except __ are glucogenic amino acids and hence can be converted directly to glucose

Answer 6

Leucine

Question 7

The rate limiting step of gluconeogenesis and is the major anaplerotic reaction in the body

Answer 7

Carboxylation of pyruvate to oxaloacetate

Question 8

Oxaloacetate cannot pass through the inner mitochondrial membrane to the cytosol hence should be reduced to ___ by ___ in the presence of NADH which becomes NAD+

Answer 8

Malate by mitochondrial malate dehydrogenase

Question 9

2nd regulatory enzyme of gluconeogenesis

Answer 9

PEPCK (PEP carboxykinase)

Question 10

Reverse the glycolytic irreversible pyruvate kinase reaction

Answer 10

Pyruvate carboxylase and PEP carboxykinase

Question 11

Number of ATPs utilized in the synthesis of a molecule of glucose during gluconeogenesis

Answer 11

6 ATPs

Question 12

General path of lactate in gluconeogenesis

Answer 12

Lactate is taken by the liver and kidney
Then converted to pyruvate via lactate dehydrogenase
Enters the mitochondria
Converted to oxaloacetate using 1st ATP
Then to PEP using 2nd ATP
Then to glucose

Question 13

General path of glycerol in gluconeogenesis

Answer 13

Delivered by blood to the liver
phosphorylate to glycerol 3-phosphate by glycerol kinase
converted to DHAP by glycerol phosphate dehydrogenase
Enters gluconeogenesis pathway

Question 14

The predominant amino acid transported to the liver from muscle proteolysis during periods of starvation

Answer 14

Alanine

Question 15

Pathway of alanine in gluconeogenesis

Answer 15

Alanine
Oxaloacetate
Glucose

Question 16

Glucogenic amino acids in gluconeogenesis give rise to net synthesis of either ___ or ___

Answer 16

Pyruvate or Oxaloacetate

Question 17

Events that yield alanine

Answer 17

Breakdown of skeletal muscle proteins during starvation

Pyruvate deamination

Question 18

Fate of alanine in the kidney

Answer 18

Deaminated and converted to urea and excreted via the urine