MSKS BioChem Lecture 2_Energy Metabolism in Muscle Part 1 Flashcards
What are the tissue expression of each of the GLUT transporters?
GLUT 1 - 5
GLUT 2 - 4
GLUT 3 - 1
GLUT 4 - 3
GLUT 5 - 2 (if you are a boy)
What is special about GLUT 4 transporters?
They are the only glucose transporter that is not always present on the surface of the cells. They are inside the cell bound to vesciles and only bind the membrane when they are activated by insulin
What is oxygens role in the electron transport chain?
It is the final electron accepter
What activates and inhibits PFK1
✓Inhibitors: ATP and citrate
✓Activators in muscle: AMP (increased AMP/ATP ratio)
✓Activators in liver: F-2,6-bisP
What activates and inhibits pyruvate kinase?
Activated by Fructose 1,6 bis phosphate (an example of feed forward regulation)
Inhibited by ATP
What are the values of Lactic acidosis
Lactic acidosis - lowers the pH of the blood
- Normal lactate (<2 mmol/L)
- Hyperlactemia (2-5 mmol/L) without
metabolic acidosis
- Lactic acidosis (4-5 mmol/L)
What is the Pyruvate dehydrogenase complex (PDH)
It is a complex of three enzymes that decarboxylate pyruvate into acetyl CoA
What are the 5 co-enzymes required for the Pyruvate dehydrogenase complex (PDH) and their associated vitamin deficencies?
Describe PDH clinical coorilations including Vitamin Deficiencies, Genetic defects in the PDH Complex, and Arsenic poisoning
What activates PDH and what deactivates it. What activates and inhibits PDH kinase? What activates and inhibits PDH phosphatase? What role does phosphoralation play in PDH regulation?
Draw it to know it: fatty acid degradation regulation
Remember, citrate can leave the mitochondria and get broken down to actyl CoA and oxcaloacetate in the cytosol
What are the three irreversible steps of the citric acid cycle? What activates them and inhibits them?
What are the oxidation reduction components of the ETC and what complexes are they found in? What are the mobile components?
What phospholipid is unique to the mitochondrial membrane? what is it’s function?
Cardiolipin is the phospholipid. It makes the membrane impervious to “leakage” of hydrogens and thus maintains the membrane potential and gradient
What is the function of Uncoupling proteins (UCPs)
UCPs make the inner mitochondrial membrane permiable to H+ without it passing through ATP synthase thus no ATP is created. A good example of this is non shivering thermogenesis in Brown adiopose tissue.
What are the 6 inhibitors of the ETC and what is their location of action?
