MCQ on Basic Lipid chemistry

Which among the following is not a function of lipids

• High energy value storage form of energy

• Carriers of genetic code

• Metabolic regulators in various ways

• Structural component of biomembranes

Answer explanation

•High energy value storage form of energy

• Fat soluble vitamins

• Steroid hormones

• Structural component of biomembranes, mitochondria and protoplasm

• Adipose tissue - Insulation against changes in external temperature

•Electrical insulators in myelinated neurons

•Shape to body

•Protect internal organs

•Metabolic regulators in various ways (eg. Steroid, acetyl CoA, prostaglandins)

•As surfactants, emulsifying agents

Spot the simple lipid from among the choices given

• Cholesterol

• Phospholipid

• waxes

• Glycolipid

Answer explanation

SIMPLE LIPIDS — Esters of fatty acid with glycerol or other higher alcohols

Fats & oils

Fatty acid esters of glycerol

Waxes

High molecular wt fatty acids esters with non glycerol alcohol

Which among the following is an unsaturated fatty acid

• palmitic acid

• stearic acid

• capric acid

• linoleic acid

The term betaoxidation refers to

• Breakdown of fatty acid

• Rancidity in fatty acid

• Auto oxidation of fatty acid

• Biosynthesis of palmitic acid

Which one among the following is an example of a lipid?

• Pasta

• Egg

• Salmon

• Fat

Name the lipid precursor of hormones like testosterone, estrogen and cortisol

• Ergosterol

• Phytosterol

• Cholesterol

• All of the above

Answer explanation

CHOLESTEROL

•Abundant in animal tissue in free state or as esters

•Cell membrane structural component

•Precursor for synthesis of

I.Bile acids, Bile salts and bile alcohol

II.Sex hormones like testosterone and estrogen

III.Other steroid hormones like adrenocorticoid steroid hormones (Cortisol, cortisone)

IV.Vitamin D

Disaccharide belong to

• Simple lipids

• Derived lipids

• Sterols

• None of the above

Unsaturation in a lipid is indicated by

• Saponification number

• Acid number

• Iodine number

• KOH number

Answer explanation

Iodine number

The number of gms of iodine taken up by 100 gm of fat

Index of degree of unsaturation. Unsaturation directly proportional to Iodine number

Butter - 28

Sunflower oil -130

The significance of phospholipids in cell membrane is

• Amphipathic nature

• Presence of choline

• Presence of fatty acid

• Hydrophilic nature

A lipid is formed by the condensation reaction between

• fatty acid and phosphoric acid

• fatty acid and glycerol

• fatty acid and alcohol

• fatty acid and carboxylic acid