Lecture 6: The Liver and Glucose Homeostasis Flashcards
what are the 3 main energy sources
- glucose
- long chain fatty acids
- amino acids
what is the main energy store
triaclglycerols which are broken down to fatty acids
what is glucose entry into the blood increased by
- glucagon
- catecholamines
- cortisol
- growth hormones
what is glucose movement out of the blood increased by
insulin
how long after a meal is glucose absorbed from the intestine
2-3 hours
how long do glycogen stores last for
12-24 hours
what are the different glucose transporter proteins and where are they found
- Glut 1: many tissues, eg erythrocytes, brain, muscle, kidney, colon, placenta, foetal tissue
- Glut 2: liver and pancreatic beta cells
- Glut 3: brain
- Glut 4: skeletal muscle and adipose tissue
- Glut 5: is a fructose transporter in the small intestine
which Glut is responsive to insulin
Glut 4
what is special about glucose metabolism in muscle and heart
- Glut 4 transporters
- some glucose stored as glycogen
- some G-6-P used in pentose phosphate pathway
- some pyruvate converted to lactic acid due to anaerobic respiration
what is special about glucose metabolism in the liver
- Glut 2 transporters
- some glucose stored as glycogen
- some G-6-P used in pentose phosphate pathway
- some pyruvate converted to lactic acid due to anaerobic respiration
- some excess acetyl coA converted to fat
what is special about glucose metabolism in the brain
- Glut 1 and 3 transporters
- no glycogen conversion
- some G-6-P used in pentose phosphate pathway
- no anaerobic respiration
what is special about glucose metabolism in red blood cells
- only anaerobic respiration
- some of the G-6-P intermediate used in pentose phosphate pathway
what is special about glucose metabolism in adipose tissue
- no glucose converted to glycogen
- some G-6-P used in pentose phosphate pathway
- excess acetyl coA converted to fat
