5 Written Questions
5 Matching Questions
- What else can muscle cells utilize to increase GLUT 4 expression even in the absence of insulin?
- What are the Class I GLUTs?
- What is the effect of insulin binding on GLUT 4?
- From where is somatostatin secreted? What two pivotal hormones in blood glucose regulation does it affect?
- Where is preproinsulin stored after synthesis?
- a - Muscle cells can utilize AMP activated protein kinase (AMPK) to increase expression even when insulin is WNL. Contraction of muscle cells also stimulates GLUT 4 translocation.
- b GLUT 1, 2, 3 and 4
- c - Formed in the delta cells of the pancreatic islets of Langerhans. Inhibits secretion of insulin AND glucagon thereby modulating their reciprocating action. So only has a minor effect on the blood glucose concentration.
- d In vesicles in the beta islet cells of the pancreas
- e Insulin binding stimulates translocation of specific GLUT 4-containing vesicles from intracellular storage to the PM resulting in an immediate 10-20 fold increase in glucose transport.
5 Multiple Choice Questions
- Decreased glucagon-stimulated cAMP production in hepatocytes. Reverses diabetes phenotype.
- Increases blood glucose level by stimulating glycogenolysis and lipolysis while inhibiting the release of pancreatic insulin.
- e- transport inhibitor; FeS to CoQ transfer/Complex II
- diffuses from the tissues and is transported to highly aerobic tissues such as cardiac muscle & liver where lactate is reoxidized to pyruvate by LDH. This pyruvate is then oxidized in the TCA cycle, while the NADH goes to ETC. If there is an energy surplus in liver cells, pyruvate will be diverted back to glucose via gluconeogenesis.
- transports glucose into rbc's, through the blood brain barrier, and most cells. Does NOT require insulin.
5 True/False Questions
What is another name for epinephrine? What organ secretes it? → ATP Synthase. Uses the energy of the PMF to synthesize ATP from ADP & Pi.
What does GLUT 2 transport? Does it require insulin to perform its activity? → glucose and fructose. Does not require insulin.
What is another name for Growth hormone (GH)? What organ secretes it & what is its effect on blood glucose concentration? → Somatotropin. Secreted by anterior pituitary. It is antagonistic to insulin in that it inhibits glucose uptake by the tissues and stimulates liver glycogenolysis thus raising blood glucose concentrations.
What are the insulin receptor substrates (IRS)? → They are the substrates of the Insulin Receptor (INSR) after insulin binds to it.
What do GLUT proteins do? → All GLUTs permit facilitated transport (diffusion) of glucose, some transport other hexose sugars as well.