5 Written Questions
5 Matching Questions
- What is the effect of insulin binding on GLUT 4?
- What cells secrete glucagon? What is it released in response to? What does it do?
- Barbiturates: Function & Site of Action?
- Amytal/Amobarbital: Function? Site of Action?
- What is another name for epinephrine? What organ secretes it?
- a 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.
- b e- transport inhibitor; Complex I
- c Adrenaline. Secreted by adrenal medulla.
- d Alpha cells of the pancreatic islets of Langerhans and L cells of GI tract cells in response to a low cellular glucose levels. It is the principal hormone for producing a rapid increase in the concentration of glucose in the blood. It does so by stimulating hepatic glycogenolysis and gluconeogenesis, but it has no effect on muscle glycogen.
- e e- transport inhibitor; FeS to CoQ transfer/Complex II
5 Multiple Choice Questions
- It is aka incretin. It upregulates insulin secretion. Mucosal cells produce it during periods of carbohydrate absorption (blood is about to be flooded w/ glucose). It is a secretagogue - a substance that causes the release of something else & is an example of an insulinotropic peptide - "insulin-loving" peptide.
- It is the main glucose transporter. Responsible for reabsorption of glucose in the glomerular filtrate. SGLT 1 is also present to assist in glucose reabsorption from urine.
- enhances the synthesis of glycogen, lipid & protein while inhibiting the breakdown of glycogen
- Decreased glucagon-stimulated cAMP production in hepatocytes. Reverses diabetes phenotype.
- transports glucose from the placenta to the fetal circulation. Involved in glucose transport into meninges. Does NOT require insulin.
5 True/False Questions
State 3 Rate → Term that describes the respiratory rate when the cell's energy charge is low. [ADP] is high and therefore electron transport rate is up-regulated by the excess ADP. [ATP Synthase has plenty of substrate to work with].
Knowing that GLUT 2 predominates in the liver and beta pancreatic cells, does it have high affinity (low Km) for glucose? → No. It has low affinity (high Km) for glucose but very high capacity! [don't want to rob extrahepatic cells of glucose in the blood].
Rotenone: Function? Site of Action? → e' transport inhibitor; Complex 1
What enzyme does the "job of glucagon" in muscle cells? → becomes reduced to CoQH2 by protons & e's from both Complex 1 and 2. It then donates the protons & electrons to Complex 3.
Which LDH isoenzyme has a lower Km (higher affinity) for pyruvate? LD H4 or LD M4? → Counterintuitive. H-type LD oxidizes lactate back into pyruvate (as seen in Heart and liver). LD H4 isoenzyme has a lower Km (higher affinity) for pyruvate and is inhibited by high levels of pyruvate. Inhibition of LD H4 by high concentrations of pyruvate, means that LD H4 won't keep adding to the alredy excessive amount of pyruvate.