Beta Oxidation

Pregunta	Respuesta
Between which 2 intermediates do we form FADH?	Fatty Acyl CoA and Trans Enol CoA.
Between which 2 intermediates do we form NADH?	3L-Hydroxacyl-CoA and 3-Ketoacyl-CoA
What is the Total ATP we can gain from Beta Oxidation of the fatty acid Palmitate (16 carbons)?	104 ATP. It costs 2 ATP to activate the Palmitate. There are 7 cycles of Beta Oxidation (thus form 7 NADH and FADH) which forms 8 Acetyl-CoA which go through the TCA cycle which forms 24 NADH and 8 FADH and 8GTP (1 GTP=1ATP BUT it costs 2 GTP to remove it across the IMM thus we generate 6ATP) In total therefore 31 NADH and 15 FADH enter the ETC generating 100ATP+6ATP from TCA-2ATP from cost of activating Palimitate=104 ATP.
What part of Fatty Acids are Hydrophobic?	The Carbon 'tail'
What part of Fatty Acids are Hydrophillic?	CoA 'head'
What are the differences between Saturated Fatty Acids and Un-saturated Fatty Acids?	Saturated Fatty acids have no double bonds between the carbon atoms and the maximum number of hydrogen atoms. Un-saturated fatty acids have one or more double bonds. Saturated Fatty acids raise bad LDL's whereas Un-saturated is found to decrease LDL's and increase HDL's.
What does Albumin do?	Fatty acids in the blood plasma bind to Albumin to make the fatty acid Water Soluble.
Explain the relationship between HSL,LPL and Insulin:	When Insulin levels are low the primary body focus is on breaking down stored energy (Fats,CHO,Proteins) as energy from food is not available. In this scenario HSL is highly active which causes the fat to leave the blood for Beta-Oxidation. When Insulin levels are high (straight after a meal) the body is storing energy from the food we eat , thus LPL is active and fat is up-taken by the blood to be distributed (Adipose) and stored.
How are Fatty Acids stored? and how do we change them so they can be released?	As TAG. A Glycerol and 3 carbon 'tails'. Lipase (HSL is most common) breaks down the TAG into 2 Fatty Acids a Monoacylglycerol and a glycerol.
What is Lipolysis?	Fat breakdown.
What factors stimulate Lipolysis?	Ca, AMP, Adrenaline, Glucagon, Cortisol, Growth Hormone, Leptin.
What factors inhibit Lipolysis?	Insulin.
How does Adrenaline work to stimulate Lipolysis?	It binds to a surfact receptor which stimulates an enzyme which forms CyclicAMP (cAMP) inside the cell which in turn activates HSL to break down TAG.
Can TAG which has been broken down from Lipolysis be reformed?	Yes through glucose-6-phosphate (formed in glycolysis) forming Glycerol-3-Phosphate which acts as a glycerol backbone with 3 phosphate points in which Fatty Acids can re-attach, this is called re-esterification.
What does the Carnitine Palmitoyl System do?	It allows Long Chain Fatty acids to enter the inner mitochondrial membrane and then into the Mitochondrial Matrix for Beta Oxidation. Acyl CoA Synthase breaks down the Fatty acid (seperates CoA 'head' and Acyl 'tail') the Acyl tail through CPT1 (on the Outer Mitochondrial Membrane) then binds with Carnitine in the cell. A Translocase Shuttle then transfers the Acyl-Carnitine to the IMM whereby through CPT2 the Acyl-carnitine is detached from the Carnitine, allowing the Acyl tail to join with a CoA 'head' in the Matrix which can then go through Beta Oxidation. The Carnitine is then free to repeat the cycle.
What happens when the Acyl-CoA is broken down to Acetyl-CoA?	The Acetyl-CoA enters the TCA cycle for additional ATP, NADH and FADH production.
What are the 4 Intermediates of Beta Oxidation?	Fatty Acyl-CoA, Trans enoyl CoA, 3-L Hydroxyacyl-CoA, 3-Ketoacyl-CoA
What are the four Enzymes of Beta Oxidation?	Acyl-CoA Dehydrogenase, Enoyl-CoA Hydratase, 3 Hydroxacyl- CoA Dehydrogenase, b-Ketoacyl-CoA thidase
What do we produce per cycle (2 carbon atoms)	1 NADH and 1 FADH
What is Beta Oxidation??	Beta Oxidation is the breakdown of fatty acids to produce NADH and FADH for energy production in the ETC
Where does Beta Oxidation take place?	Mitochondria
Fatty acids have to be transported into the Mitochondrial Membrane, but what substance is this dependent on?	Carnitine
What are fatty acids?	Fatty Acids are carbon atoms attached to a CoA backbone.
Whats the difference between Acyl-CoA and Acetyl-CoA?	Acetyl-CoA only has 2 attached carbon atoms. Acyl-CoA has a lot of attached carbon atoms, for example Stearic Acid is an 18 carbon fatty acid.
What is the general process?	It is the cleaving of two carbon atoms from Acyl-CoA per cycle to form NADH and FADH.

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	Creado por Mark Arsenal hace más de 11 años