Fatty acids/lipids

[au5233]

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Hey, some questions about fatty acids and lipids.

1. So Smooth ER makes LIPIDS, but FATTY ACIDS are made in the cytosol right?

2. In gluconeogenesis, it can ONLY use the glycerol portion to make glucose right?

3. In contrast, glycerol can enter krebs as PGAL AND fatty acids can be broken down via Fatty acid catabolism to make acetyl co-A.

4. Does fatty acid oxidation occur in the mitochondrial matrix? And gluconeogenesis occurs there as well? What part of a liver cell does the Cori cycle occur?

5. Liver functions: Cori cycle and gluconeogenesis. Anything else?

 

[sacjumpman]

Hey, some questions about fatty acids and lipids.

1. So Smooth ER makes LIPIDS, but FATTY ACIDS are made in the cytosol right?
Yes. I think they generalize that smooth ER makes "lipids," because they are capable of making different steroids, etc. Fatty acids are assembled in the cytosol. This requires a large amount of reducing power in the form of NADPH provided by glucose sent through the Pentose Shunt pathway.

2. In gluconeogenesis, it can ONLY use the glycerol portion to make glucose right?
Yes. In vertebrates this is true. However, plants and some bacteria are capable of making glucose via the fatty acid. However, vertebrates lack two enzymes necessary for this process to work. This process (which occurs in plants and some bacteria, such as yeast) is known as the glyoxylate cycle and occurs in the glyoxysome. This process of converting fatty acids into glucose is especially important in the germinating seed.

3. In contrast, glycerol can enter krebs as PGAL AND fatty acids can be broken down via Fatty acid catabolism to make acetyl co-A.
Yes.

4. Does fatty acid oxidation occur in the mitochondrial matrix? And gluconeogenesis occurs there as well? What part of a liver cell does the Cori cycle occur?
Yes. Fats are first "activated" into an acyl-CoA (get CoA attached) molecule in the intermembrane space of the mitochondria. Then moved into the matrix to undergo B oxidation. Not sure about the Cori cycle, though it does happen in the liver...

5. Liver functions: Cori cycle and gluconeogenesis. Anything else?
A few off the top of my head: synthesis of lipids
Albumin production
Bile production
Destruction of red blood cells
Nitrogenous waste ---> urea
Glycogen storage

But Cori cycle and gluconeogenesis are two important ones as well.

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