Biologically active lipids

Question 1

What do phospholipases do?

Answer 1

Cleave phospholipids

Question 2

Where in a phospholipid does phospholipase A cleave?

Answer 2

Ester bonds

Question 3

Where in a phospholipid does phospholipase C cleave?

Answer 3

Right before the phosphate

Question 4

Where in a phospholipid does phospholipase D cleave?

Answer 4

Between the phosphate and the polar head

Question 5

What does phosphatidylinositol do?

Answer 5

Involved in signalling. Gets cleaved by PLC to form IP3 and DAG

Question 6

Why are some sterols biologically active?

Answer 6

Are the precursors for steroid hormones

Question 7

What are 4 steroid hormones?

Answer 7

Testosterone, beta-estradiol, cortisol, prednisone

Question 8

What are eicosanoids?

Answer 8

Derivatives of arachidonic acid

Question 9

What are the 3 eicosanoids derived from arachidonic acid? What do they do?

Answer 9

Prostaglandin E1: inflammation
Thromboxane A2: blood clotting
Leukotriene: smooth muscle contraction of the airway

Question 10

What are the 3 fat-soluble vitamins? What do they do?

Answer 10

Vitamin E: antioxidant and forms tocopherol
Vitamin A: Forms retinol and is required for vision
Vitamin D: forms cholecalciferol and is important for bones

Question 11

How do you identify the structure of a lipid molecule?

Answer 11

Separate it out by chromatography by eluting more hydrophobic things out first, then do mass spec on it