Fatty acid metabolism Flashcards
(22 cards)
Why do we need to synthesise fatty acids?
To provide energy storage, build membranes, and synthesize signaling molecules.
What are key roles of fatty acids in the body?
Energy storage, membrane components, hormones, pigments, detergents.
What is the precursor molecule for fatty acid synthesis?
Acetyl-CoA.
What is malonyl-CoA and why is it important?
An activated form of acetyl-CoA required to initiate synthesis.
What enzyme catalyzes the formation of malonyl-CoA?
Acetyl-CoA carboxylase.
Where does fatty acid synthesis occur in the cell?
In the cytosol of liver and adipose tissue.
What is fatty acid synthase?
A multifunctional enzyme complex that catalyzes fatty acid synthesis.
What are the four steps of fatty acid synthesis?
Condensation, reduction, dehydration, and a second reduction.
What is the end product of fatty acid synthesis in mammals?
Palmitate (16:0).
How is fatty acid synthesis regulated?
Via hormonal control (insulin upregulates; glucagon inhibits).
What are the three sources of fatty acids for energy?
Dietary fats, stored fats in adipose tissue, fats synthesized and exported.
Which organs rely heavily on fatty acid catabolism?
Liver, heart, and resting skeletal muscle.
What is the carnitine shuttle used for?
To transport long-chain fatty acids into mitochondria.
What is β-oxidation?
A metabolic pathway that breaks down fatty acids into acetyl-CoA.
Where does β-oxidation occur?
In the mitochondrial matrix.
What are the four recurring steps in β-oxidation?
Oxidation, hydration, oxidation, thiolysis.
What are the net products of palmitate oxidation?
8 acetyl-CoA, 7 NADH, 7 FADH2 from palmitate.
How much ATP does full oxidation of palmitate yield?
108 ATP from one molecule of palmitate.
Why are fatty acids efficient energy storage molecules?
They are highly reduced and yield more energy per carbon.
What happens to acetyl-CoA after β-oxidation?
It enters the TCA cycle for further energy production.
How is β-oxidation regulated?
By energy needs, hormonal signals, and malonyl-CoA levels.
How do unsaturated fatty acids enter β-oxidation?
They require additional enzymes to convert to β-oxidation intermediates.
