Biochemistry Final Exam: UNE CHEM 1005 Exam Questions And Answers

Biochemistry Final Exam: UNE CHEM 1005 Exam Questions And Answers Control of Fatty Acid Synthesis vs. Oxidation - ANS When Insulin is HIGH --> fatty acid synthesis occurs When Glucagon is HIGH --> lipolysis, fatty acid B-oxidation, ketogenesis occur **These never happen at the same time! Lipolysis - ANS Process of releasing free fatty acids from triacylglycerols stored in the adipose IN THE FASTED STATE Steps of lipolysis - ANS 1) Hormone Sensitive Lipase: activated by glucagon and epinephrine TAGs are hydrolyzed into FFAs and glycerol (inhibited by insulin) 2) Long chain FFAs travel bound to albumin to peripheral tissues to be used as energy source 3) Glycerol travels to liver to be used as gluconeogenesis substrate 4) Acyl-CoA Synthetase: can reconvert FFAs to acyl-CoA to be used for re-esterification in the adipose (continuous cycle of lipolysis & re-esterification) Beta Oxidation - ANS Process of generating acetyl-CoA, NADH, and FADH2 from the oxidation of FFAs taken up by peripheral tissues (mostly liver & skel. muscle tissue). Happens in mitochondria. Long chain FFAs cannot cross the mito membrane, so a transport system is in place. Ketogenesis - ANS Process of generating ketones from excess acteyl-CoA produced from Beta-Oxidation Mitochondrial pathway Ketones can be used as fuel by other tissues but cannot be oxidized by... - ANS The liver. Skeletal muscle can oxidize ketones. The brain will oxidize ketones when starving. Ketogenesis is regulated by... - ANS 1) Activity of lipolysis 2) Cytosolic levels of malonyl-CoA (which inhibit CPTI) 3) Flux through the TCA depending on NADH levels & concentration of intermediates (especially OAA)