Gluconeogenesis

Question 1

What is gluconeogenesis?

Answer 1

Synthesis of glucose from carbs, non carbs when glucose depleted and glycogen is depleted. Important during starvation.

Question 2

Where does gluconeogenesis occur?

Answer 2

Liver, kidney and small intestine

Question 3

Why is gluconeogenesis not reverse of glycolysis?

Answer 3

Because it bypasses the irreversible steps of glycolysis (HK/GK, PFK1, PK)

Question 4

What are the 4 major enzymes of GNG?

Answer 4

Pyruvate Carboxylate (mito)

PEPCK: Phosphoenolpyruvate Carboxykinase

Fructose 1,6 Biphosphatase

Glucose 6-Phosphatase

Question 5

RLS of GNG?

Answer 5

Frutose 1,6 Biphosphatase

Question 6

What does cori cycle do?

Answer 6

LINKS lactate from anaerobic glycolysis and exercising muscles to GNG in liver. This then pumps glucose back into RBC and Muscle

Question 7

Precursors of gluconeogenesis?

Answer 7

Fructose
Galactose
Lactate
Glycogen

Propionate
Alanine
Amino Acids

Question 8

F1, 6BP Deficiency

Answer 8

In infancy or childhood

Causes hypoglycemia, lactic acidosis, ketosis

Can’t complete gluconeogenesis since this is RLS

Question 9

Von Gierke Dx (GSD1a)

Answer 9

glucose-6-phosphatase deficiency

Glucose stays in liver and not making free glucose avail.

Pt presents with fasting hypoglycemia, hepatomegaly due to glycogen build up.