Question

1. Triacylglycerols, or triglycerides, are triesters formed from glycerol and three _____ molecules. 2. Triacylglycerols are stored in _____ cells below the skin and concentrated in some regions of the body. 3. The _____ is the aqueous medium inside the cell, separated from water outside the cell by the cell membrane. 4. Which statement is not true? a) Vitamin A is obtained from liver, oily fish, and dairy products. b) Vitamin E is an antioxidant, protecting unsaturated side chains in fatty acids from unwanted oxidation c) A severe deficiency of vitamin K leads to excessive and sometimes fatal bleeding because of inadequate blood clotting. d) Vitamin A helps regulate both calcium and phosphorus metabolism. 5. Which statement is not true? a) Cholesterol is the most prominent member of the steroid family b) Cholesterol is insoluble in the aqueous medium of the blood c) Cholesterol serves as the starting material for the synthesis of all other steroids and vitamin A. d) Cholesterol is a vital component for healthy cell membranes e) Cholesterol is synthesized in the liver.

Answer 1

1. Triacylglycerols, or triglycerides, are triesters formed from glycerol and three fatty acid molecules.

2. Triacylglycerols are stored in adipose (fat cells) cells below the skin and concentrated in some regions of the body.

3. The cytosol is the aqueous medium inside the cell, separated from water outside the cell by the cell membrane.

4. Incorrect option is (d): Vitamin A helps regulate both calcium and phosphorus metabolism.

Because vitamin D helps to regulate both calcium and phosphorus metabolism. All other option are true.

5. Incorrect option is (c): Cholesterol serves as the starting material for the synthesis of all other steroids and vitamin A.

Cholesterol, the most common steroid, is mainly synthesized in the liver and is the precursor to many steroid hormones. Cholesterol also serves as the starting material for other important molecules in the body, including vitamin D and bile acids. It is not a starting material for all steroids and not for vitamin A. All other options about cholesterol are true. It is synthesized in liver and is vital component for healthy cell membranes.