Glycolysis Flashcards
After Glucose comes into the cell, either hexokinase or glucokinase adds a phosphate and traps it in the cell. What is the difference between these 2
- Hexokinase: low Km, high affinity for glucose, low Vmax, NOT induced by insulin
- Glucokinase: Unique to cells that regulate glucose (Liver and Beta cells), high Km, high Vmax, induced by insulin
What are the 2 different shuttles involved in Aerobic metabolism? how much ATP does each produce
- Malate-Aspartate Shuttle (32 ATP)
- Glycerol-3-phosphate shuttle (30 ATP)
Where is the Malate-Aspartate Shuttle found
- heart
- liver
- Kidneys
Where is the Glycerol-3-phosphate shuttle found?
Brain and skeletal muscle
Where are GLUT-1 found?
What does this mediate?
- RBCs
- Endothelium of BBB
- mediates basal glucose uptake
Where is GLUT-2 found?
- on cells that regulate glucose
- Hepatocytes
- Pancreatic Beta-cells
Where is GLUT-3 found
- neurons
- Placenta
Where is GLUT-4 found?
- insulin dependent
- Skeletal muscle
- Adipose tissue
What is GLUT-5
mediates FRUCTOSE uptake in GI tract
Rate limiting enzyme of Glycolysis
-PFK-1
What are the 3 irreversible steps of Glycolysis that have to be bypassed in another way during gluconeogenesis
- Hexokinase or Glucoskinase
- PFK-1
- Pyruvate Kinase
What things stimulate PFK-1
- AMP
- Fructose-2,6-bisphosphate
What things inhibit PFK-1
- ATP
- citrate
What stimulates Pyruvate Kinase?
Fructose-1,6-bisphosphate
What inhibits pyruvate Kinase?
- ATP
- Alanine
