Lecture 6 Flashcards
(17 cards)
What is Gluconeogensis?
Creation of glucose from 3-carbon precursors
- lactate
- pyruvate
What is Glycolysis?
Anaerobic breakdown of glucose into 3 carbon molecules and energy
Glycogenesis
Production of glycogen from glucose
Glycogenolysis
Breakdown of glycogen to glucose
Absorptive (fed) state in omnivores
Occurs immediately after eating
- Glucose plentiful
- Extra glucose converted to first to glycogen and secondly to fat
- Lipids are stored as triglycerides
- AA converted into protein
Post-absorptive (fasting state)
Begins 3-4 hrs after eating
- Glycogen broken down to glucose
- Glucose formed through gluconeogenesis
- Fat breakdown to fatt acids
- Protein catabolis to aa
What is the primary hormone of the fed state?
Insulin
Overall effect of insulin
Lower blood concentrations of
- glucose
- amino acids
- fatty acids
What do transporters GLUT 1-6 do?
Allow passive diffusion of glucose into cells
Of the Glut transporters which is the only insulin dependent transporter and where is it found?
Glut -4
Muscle and Adipose tissue
Effect of insulin on GLUT-4 transporter
Insulin binds to its receptor
GLUT 4 molecules stored in cytoplasm bind to cell membrane and become active
Other than insulin, what else increase GLUT-4 receptors?
Exercise
What stimulates release of insulin?
Increase in blood glucose and a.a. concentrations
What is insulin receptor down-regulation?
When insulin binds to receptor - receptor is endocytosed with insulin
Decrease in receptors results in decreased response to insulin
What do strict carnivores do that is different from other animals after eating?
Release both insulin and glucagon
- Strict carnivores are hypoglycemic upon eating and insulin would cause an increase in hypoglycemia, therefor Glucagon is released to counteract the effects of insulin
Types of Diabetes Mellitus
Type I - insulin dependent, juvenile diabetes
Type II (non-insulin dependent) - Reduced sensitivity to insulin due to down regulation of insulin receptors, potential beta-cell burnout
Between type I and type II which would benefit most from exercise?
Type II - exercise increase GLUT - 4 on membranes
