L27 Gluconeogenesis Flashcards
Gluconeogenesis is the synthesis of…
Glucose from pyruvate
Parts of gluconeogenesis take place in the…
a) cytosol
b) mitochondrial intermembrane space
c) mitochondrial inner membrane
d) nucleus
a) Cytosol
The first step takes place in the mitochondrial matrix. Subsequent steps occur in the cytosol
Energy for gluconeogenesis provided by:
a) Oxidation of carbohydrate fuels
b) Reduction of carbohydrate fuels
c) Oxidation of non-carbohydrate fuels
d) Reduction of non-carbohydrate fuels
c) Oxidation of non-carbohydrate fuels
Particularly fats
For gluconeogenesis to be energetically possible…
3 irreversible steps in glycolysis must be bypassed
Glycolysis and gluconeogenesis are controlled by…
Allosteric regulation (of the enzymes catalyzing the 3 irreversible steps)
Normal blood glucose concentration in the plasma is…
4-6 mmol/L
Blood glucose concentrations are maintained by the balance between…
Glucagon and insulin
The brain makes up how much of the body’s glucose use?
a) 75%
b) 50%
c) 8%
d) 87%
a) 75%
When might hypoglycemia occur (3)?
- After insulin overdose in Type I diabetes
- During starvation
- During and after exercise
Hyperglycemia may occur in Type I diabetes as a result of…
Insufficient insulin dose
Long term complications of hyperglycemia include…
Eyesight failure and vascular disease
Gluconeogenesis occurs principally in the…
a) Kidneys
b) Brain
c) Liver
d) Gall bladder
e) All of the above
c) Liver
Gluconeogenesis allows the preservation of…
Glycogen stores for emergencies
Gluconeogenesis requires…
4ATP + 2GTP
In the Cori cycle…
Lactate from the muscle is transported to the liver where it is converted to pyruvate and then to glucose, which is fed back to the muscles
