Side Notes from Lectures

Feedback Inhibition: End production of a reaction stops/slows down activity of an enzyme

Feed Forward Activation: Upstream molecule activates enyme early in pathway to increase production of a product

Allosteric Regulation: Enzymes controlled by molecules that bind on allosteric sites (Inhibites AND activates)

Substrate level phosphorylation: Phosphate placed directly on ATP

Kinase: Enzyme that catalyzes the transfer of phosphate group to high energy molecule

How do you generate/regenerate NAD?

• Pyruvate reduces to lactate via lactate dehydrogenase enzyme → NADH is then oxidized to NAD+ (Anaerobic)

• Pyruvate converted to acetylCoA → Co2 released via enzyme decarboxylase, reduces to EtoH —> NADH oxidized to NAD (Anaerobic)

Where does glycolysis occur?

• In the muscle + brain

Where does gluconeogenesis occur?

• In the liver + kidney

What is the Cori Cycle? (Lactic Acid Cycle)

• The process in which lactate and glucose are exchanged between the muscles and liver

• Starts in the muscle: Glucose → pyruvate → lactate.. then releases lactate into the blood stream. (Generates 2 ATP)

• Then: Lactate travels to liver —> undergoes gluconeogenesis. Lactate → pyruvate → glucose → then released into blood stream where muscle can uptake again. (Loses 6 ATP)

Glycogen: stored form of glucose

• Branched polymer of a-14 and a1-6 linked glucose monomers

• Found in liver and muscle

• Storage regulated by norepinephrine and epinephrine

Glycolysis: the process of converting glucose into pyruvate

• Glycogenin: core protein that starts the process of building glycogen, “primer”

• Glycogen synthase: enzyme that adds glucose units to molecule chain

• Branching enzyme: creates branches in the glycogen to make it more compact/easy to break, also helps break down glycogen when needed

Insulin and the effects on gluconeogenesis and glycogen

• Insulin: lowers blood sugar, is high after eating/sugar uptake

• High insulin: inhibition of gluconeogenesis (production of gluose), activation of glycolysis (glucose to pyruvate)

• Low insulin: activation of gluconeogenesis (body needs more glucose because sugar is low), inhibition of glycolysis (don’t need to store b/c the body is already low of energy)