Lipids 2 Flashcards
Can fatty acids be converted into glucose?
NO
What does the beta-oxidation pathway do?
Degrades fatty acids two carbons at a time production acetyl CoA, NADH and FADH2 in the mitochondrial matrix.
What are the stages of the beta-oxidation pathway?
Fatty acids activated in the cytosol forms fatty acyl CoA
Transported into the mitochondria via carnitine shuttle
Degradation to two carbon fragments - Dehydrogenation to produce FADH2, hydration, Dehydrogenation to produce NADH and finally thiolysis to produce acetyl CoA.
Describe the Carnitine Shuttle.
Major site of regulation
Transferase is inhibited by malonyl CoA, needed for fatty acid synthesis.
Prevents synthesis and degradation occurring simultaneously
90% in skeletal muscle.
What is the energy yield?
2x7 from production of FADH2 3x7 from production of NADH 12x8 from production of acetyl CoA -2x1 from production of palmitoyl CoA Total = 129 ATP
What do fatty acid chains with more than 22 carbons have to undergo?
Preliminary beta-oxidation in peroxisomes.
Why is the first step of preliminary beta-oxidation not energy efficient?
No production of FADH2
What can happen when there is excess acetyl CoA?
Two can bind together to form ketone bodies.
What can use ketone bodies as an energy source?
Cardiac and skeletal muscles to fuel the brain during fasting or starvation.
Where are ketone bodies made and why can they be transported easily?
They are made in the liver and are water soluble and small so travel easily.
What can excessive ketone bodies cause?
Uncontrolled diabetes and leads to a very high ketone body concentration in the blood.
