Term
Fatty Acids (FAs)
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Definition
i. Amphipathic hydrocarbon chain
1. The tail is hydrophobic and the head is hydrophilic
ii. Saturation
1. Tail made of all single bonds= saturated
2. Tail made of a combination of single and double bonds=unsaturated
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| What 2 FAs are essential and what do they precursors for? |
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Definition
iii. Linoleic and linolenic are classified as essential, must get from good fat foods because they cannot be produced
1. Linolenic- precursor for omega 3 fatty acids
2. Linoleic- precursor for omega 6 FA. Linoleic is a precursor for arachidonic acid (a precursor for metabolic processes |
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| What are the 2 most abundant FAs? |
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| Palmitic acid and stearic acid |
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| Describe the structure of FAs |
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Definition
i. Glycerol backbone with 3 FAs
1. The first one is always saturated
2. The second one is usually unsaturated
3. The third one can be saturated or unsaturated
4. It is possible to have all 3 FA saturated but they cannot all be unsaturated |
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| TAGs breakdown to what by what process |
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| Fas breakdown to what via what process |
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Definition
| acetyl CoA via Beta oxidation |
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| WHat are the fates of acetyl CoA |
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Definition
i. Acetyl CoA then enter the TCA cycle
ii. Acetly CoA converted to ketone bodies via
ketogenesis
iii. It may be converted into cholesterol via
cholestrologenesis |
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| Acetyl CoA is converted to what via what process |
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| FAs are converted to what by what process |
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| Describe hormone sensitive lipase |
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Definition
1. Rate limiting step in lipolysis that occurs during the fasting state
2. Removes FA from Carbon 1 and Carbon 3 forming 2-monoacylglycerol
3. It is active when phosphorylated by PKA
4. Its stimulated by epinephrine and glucagon
5. Inhibited by insulin (inhibits PKA) and glucose |
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| What are the steps of lipolysis? |
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Definition
a. Glucagon or Epinephrine will bind to B-adrenergic receptors
b. The receptor is a g protein activated receptor that activates adenylate cyclase
c. Adenylate cyclase converts ATP to cAMP
d. cAMP activates protein kinase A (PKA)
e. PKA uses ATP to phosphorylates hormone-sensitive lipase
f. It catalyzes the reaction TAG to DAG. The first FA removed is the C1 saturated FA
g. DAG to MAG is also catalyzed by it and the FA on C3 is cleaved
h. MAG is converted to glycerol and FA by MAG lipase |
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| What is the fate of glycerol after lipolysis? |
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Definition
i. Transported from adipose to the liver
ii. Converted to glycerol phosphate by glycerol kinase
1. The glycerol is either stored in the liver as TAG or
2. Converted to DHAP by glycerol phosphate dehydrogenase and enter gylcoylysisor gluconeogenesis |
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| What is the fate of FA after lipolysis |
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Definition
i. FA diffuses into the bloodstream and associates with serum albumin
ii. Then diffuses into the perpherial tissue cells to become activated
iii. The FA can then undergo B-oxidation
iv. Energy is produced |
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