Biosynthesis

Question 1

What is glycerol phosphate derived from?

Answer 1

Reduction of DHAP or phosphorylation of glycerol.

Question 2

How is phosphatidate made?

Answer 2

Adding two fatty acids to glycerol 3-phosphate

Question 3

Why is phosphatidate important?

Answer 3

Intermediate in the synthesis of triacylglycerols and phospholipids.

Question 4

What are the ways that phospholipids can be synthesized?

Answer 4

Activated diacylglycerol or activated alcohol

Question 5

Another name for sphingolipids.

Answer 5

Ceramide

Question 6

What is ceramide synthesized from?

Answer 6

Dihydrosphingosine

Question 7

What do ceramides synthesize?

Answer 7

Sphingomyelin, cerebrosides, and gangliosides

Question 8

What is cholesterol synthesized by?

Answer 8

Acetyl CoA

Question 9

How many stages are in the synthesis of cholesterol and what are they?

Answer 9

5
1. Synthesis of a 6-carbon molecule (mevalonate) - rate-limiting step
2. Mevalonate converted to 5-carbon isoprene
3. Isoprene goes to geranyl, farnesyl, and squalene through condensation
4. Squalene forms steroid lanosterol
5. Lanosterol converts to cholesterol

Question 10

How is HMG CoA reductase controlled?

Answer 10

1. Transcriptional control
2. Phosphorylation control

Question 11

What is derived from cholesterol?

Answer 11

Vitamin D

Question 12

How are cholesteryl ethers synthesized?

Answer 12

Adding a fatty acid to cholesterol