Lecture 8: Glucose Metabolism Flashcards
What GLUT receptor is found in skeletal muscle, heart and adipose and is insulin dependent?
GLUT4
What GLUT receptor is the main ransporter in the liver and has low affinity with no regulation?
GLUT2
What GLUT transporter is the main transporter in the brain?
GLUT3
What GLUT transporter is high in RBCs and brain and has high affinity?
GLUT1
Where are glucokinase and hexokinase located?
Glucokinase is in the liver only, hexokinase is everywhere else
When is glucokinase inhibited?
When blood glucose is low -> it is no preferred to trap glucose in the liver so glucokinase will only be turned on in times of high glucose
When is DHAP made in glycolysis?
High energy state and excess glucose
- DHAP is converted to glycerol-3-phosphate then to fat
What is non-alcoholic fatty liver disease?
YOu have a buildup of energy and DHAP gets turned into fat
What stimulates pyruvate kinase?
Insulin and Fru-1,6-BP
What inhibits pyruvate kinase?
Alanine
ATP
Glucagon
What inhibits hexokinase?
Glucose-6-P
What stimulates glucokinase?
Glucose
Fructose-1-P
Insulin
What inhibits glucokinase?
Glucagon
Fructose-6-P
What stimulates PFK-1?
AMP
Fructose-2,6-BP
What inhibits PFK-1?
ATP
Citrate
___________ is a disaccharide of glucose and fructose
Sucrose
_________ is a disaccharide of glucose and galactose
Lactose
Where does galactose enter glycolysis?
Glucose-6-P
- Then could go onto gycogenesis if no energy is needed
Where does fructose from adipose tissue enter glycolysis?
Fructose-6-P
Where does fructose from the liver enter glycolysis?
DHAP or GAP
When is fructose quickly turned into fat?
In times of high energy
What does glucose-6-P feedback inhibit and when?
Hexokinase at times of rest
What is the role of glucose-6-phosphatase?
The convert GLucose-6-P to glucose in gluconeogenesis
Gluconeogenesis is the synthesis of glucose from noncarb precursors. What are the 3 major precursors?
Lactate, amino acids, glycerol
