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Flashcards in Lipids 2 Deck (11)
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1
Q

Can fatty acids be converted into glucose?

A

NO

2
Q

What does the beta-oxidation pathway do?

A

Degrades fatty acids two carbons at a time production acetyl CoA, NADH and FADH2 in the mitochondrial matrix.

3
Q

What are the stages of the beta-oxidation pathway?

A

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.

4
Q

Describe the Carnitine Shuttle.

A

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.

5
Q

What is the energy yield?

A
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
6
Q

What do fatty acid chains with more than 22 carbons have to undergo?

A

Preliminary beta-oxidation in peroxisomes.

7
Q

Why is the first step of preliminary beta-oxidation not energy efficient?

A

No production of FADH2

8
Q

What can happen when there is excess acetyl CoA?

A

Two can bind together to form ketone bodies.

9
Q

What can use ketone bodies as an energy source?

A

Cardiac and skeletal muscles to fuel the brain during fasting or starvation.

10
Q

Where are ketone bodies made and why can they be transported easily?

A

They are made in the liver and are water soluble and small so travel easily.

11
Q

What can excessive ketone bodies cause?

A

Uncontrolled diabetes and leads to a very high ketone body concentration in the blood.