Lipids 3 Flashcards
Where do we get FA’s?
- Diet
- Synthesis
Where does FA synthesis occur in the body?
- Liver
- Lactating mammary
- Adipose tissue
Where does synthesis occur in the cell?
Cytosol
What are FA’s synthesised from?
Acetyl CoA
Where is the acetyl CoA from in FA synthesis?
Mitochondria
When does the citrate cycle occur? (when what is in high concentration)?
Citrate
What 2 enzymes are required for FA synthesis?
- Acetyl CoA carboxylase
- FA synthase
What are the 2 required molecules for synthesis?
- Acetyl CoA
- NADPH
What is the product of FA synthesis?
Palmitic Acid
What is acetyl CoA initially converted to?
Malonyl CoA
What other action does Malonyl CoA have to stop synthesis and degradation occurring simultaneously?
Inhibits carnitine palmitoyl transferase
What activates acetyl CoA carboxylase?
- Citrate
- Insulin
What deactivates acetyl CoA carboxylase?
- Palmitoyl CoA
- Glucagon
- Epinephrine
What does malonyl CoA combine with in the elongation reaction
Acetyl ACP
What happens after elongation?
The reverse of FA degradation
What is used in the reverse of degradation instead of NADH?
NADPH
How many times is the elongation reaction carried out?
6 times
What is produced initially by the elongation reaction?
Palmitoyl ACP
How is palmitoyl CoA produced?
Cleaved from palmitoyl ACP
What 2 pathways does the NADPH required for synthesis come from?
- Pentose phosphate pathway
- Production of pyruvate from malate in the CAC
What happens to the FA after it has been synthesised?
Transported to the liver
What happens to the FA in the liver and how is it transported to the adipose tissue?
- Synthesised into TAG
- Transported through VLDL
What is the starting lipid for the production of steroid hormones?
Cholesterol
What are eicosanoids produced from?
- FA’s longer than 20 C’s
- Omega 3/6 from linolenic acid
What are 4 examples of eicosanoids?
- Leukotrienes
- Prostaglandins
- Arachidonic acid
- Thromboxanes
What enzymes synthesise prostaglandins?
- COX enzymes
