overview of gluconeogenesis

Question 1

Gluconeogenesis

Answer 1

glucose new synthesis from non-carb sources

pyruvate is derived from?
- glucogenic amino acids
- lactate
- alanine?

Question 2

red blood cells need glucose why?

Answer 2

• no mitochondria
• OTHER cells use mitochondria for processing fatty acids / b-oxidation to breakdown fat.

SO RBC have no energy soure other than certain amino acids and lactate.

Question 3

90% of GNG…

Answer 3

occursin the liver
The last step goes around HK in glycolysis, and most tissues do not do this step.
(G6P to Glucose is the last step)

Why? because enzymes would take P off and GLUT transporter would take it outside of the cell..

BUT liver will do this step, to buffer blood glucose levels

Question 4

GNG and glycogenolysis maintain…

Answer 4

overnight fasting glucose levels and can help maintain blood glucose in long term exercise.

Glucose must be made during fasting conditions

Question 5

GNG and glycolysis are concurrent

Answer 5

Always running both at the same time.
GNG is glyc is reverse but steps 10,3,1 need to be gone around.

Need 4 unique reactions (10 requires 2 of those)

Question 6

Unique rxns;

Answer 6

PC, PEPCK, FBPase-1, G6Pase

Question 7

Liver cells

Answer 7

ATP is used and NADH is oxidized in GNG

Question 8

In the liver, where do these molecules come from?

Answer 8

Coming from B-oxidation of fat….
b-ox is supporting GNG

Question 9

cost of GNG

Answer 9

4 ATP and 2 GTP

Question 10

starting materials of GNG

Answer 10

• Pyruvate
• Lactate: (cori cycle)
• citric acid cycle intermeds.:(CAC/TCA)
• C-skeletons of most AA (glucogenic)
• glycerol from TriAcylGlycerol metab (has fatty acids, glycerol can be converted to be used as a starting)

Question 11

Cori cycle

Answer 11

• skeletal muscle receive gluc from blood stream (maybe liver or diet/small intestine)
• can store as glycogen
• can run glycolysis or anaerobic glycolysis (lactate)
• can send back to liver to use as starting material for glycolysis