Lipid metabolism Flashcards
What does Fatty acid metabolism lead to?
Acetyl CoA production
What are triglycerides made out of?
Fatty acids Glycerol
What are the 3 sources fats are derived from?
The diet De novo biosynthesis (liver) Storage depots in adipocytes.
What disease is caused by a lack of bile salts?
A lack of bile salts results the majority of fat passing through the gut undigested and unabsorbed resulting in steatorrhea (fatty stool).
What is Beta Oxidation?
beta-oxidation is the catabolic process by which fatty acid molecules are broken down in the cytosol in prokaryotes and in the mitochondria in eukaryotes to generate acetyl-CoA, which enters the citric acid cycle
Summarise the steps for Beta oxidation?
1)Firstly, fatty acids are converted into an acyl CoA species 2)The acyl CoA species is transported across the inner mitachondrial membrane using the carnitine shuttle 3) When in the matrix, The acyl CoA undergoes a sequence of oxidation, hydration, oxidation and thiolysis reactions (collectively called β-oxidation). This results in the production of one molecule of acetyl CoA and an acyl CoA species which is 2 carbons shorter than the original. add pic
What are the products of beta oxidation?
one molecule of acetyl CoA and an acyl CoA species which is 2 carbons shorter than the original. For each cycle a molecule each of FADH2 and NADH
For a 16-carbon palmitoyl CoA, how many Beta oxidation reactions must occur and how many molecules of acetyl CoA can be produced?
From just 7 b-oxidation reactions, the 16-carbon palmitoyl CoA molecule produces 8 molecules of acetyl CoA.
Why are ketone bodies produced whilst fasting?
Acetyl CoA generated by β-oxidation enters the TCA cycle only if β-oxidation and carbohydrate metabolism are balanced, since oxaloacetate is needed for entry (lecture 4). Hence the adage “Fat burns in the flame of carbohydrate”. When fat breakdown predominates e.g. during fasting, acetyl CoA forms acetoacetate, D-3-hydroxybutyrate and acetone known collectively as ketone bodies.
What is the difference between beta oxidation and lipogenesis in respect to location, coenzymes and carrier molecules.
Carriers:ACP(synthesis) and CoA(Beta oxidation) Coenzymes: NADPH(synthesis) and NAD+/FAD (Beta oxidation) Location: Cytoplasm( synthesis) and Mitachondrial matrix (Beta Oxidation)
what is lipogenesis?
Lipogenesis is the process by which acetyl-CoA is converted to fatty acids.
Name some disorders of fatty acid Oxidation?
Medium-chain acyl-coenzyme A dehydrogenase deficiency (MCADD) Primary Carnitine deficiency
