Biology · Chemistry

Lipids, Fats, and Biochemistry

1,130 Questions

Lipids, fats, and biochemistry explore the structure and function of biological molecules. This includes fatty acids, cholesterol, trans-fats, and cellular membranes. Questions on this topic frequently appear in science sections of competitive government exams.

Types of fats and lipidsCholesterol and human bodyFatty acidsCellular membranes

Lipids, Fats, and Biochemistry Questions

Multiple choice

Lipids in the plasma membrane have

  1. hydrophilic part only

  2. hydrophobic part only

  3. both hydrophilic and hydrophobic parts

  4. no fatty acid chains
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Most of the lipids in biological membranes are phospholipids. Phospholipids have both hydrophilic regions and hydrophobic regions. In hydrophilic regions, phosphorus containing head of phospholipid is electrically charged and hence associates with polar water molecules. In hydrophobic regions, long, nonpolar fatty acid tails of the phospholipids associate with other nonpolar materials, but they do not dissolve in water or associate with hydrophilic substances.

Multiple choice

Calorific value of fat is

  1. 4.2 kcal/gram

  2. 9.5 kcal/gram

  3. 4.1 kcal/gram

  4. 5.1 kcal/gram
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Fats yield 9.5 kcal/gram, carbohydrates 4.2kcal/gram and proteins about 4.1 kcal/gram.

Multiple choice

Fats are richly found in

  1. areolar tissue

  2. adipose tissue

  3. lymph glands

  4. tendon
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Fats are richly found in adipose tissue, which have fat storing adipocytes.

Multiple choice

Animal cell membrane is a flexible lipid bilayer. Among the following, -------------- is a vital component in the structure of cell membranes in the human body.

  1. calcium 2-aminoethylphosphate

  2. calcium-alpha-ketoglutarate

  3. calcium β-hydroxy-β-methylbutyrate

  4. dodecacalcium hepta-aluminate
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Calcium 2-aminoethylphosphate (Ca-AEP or Ca-2AEP) is a vital component in the structure of cell membranes in the human body. It is the calcium salt of phosphorylethanolamine. Ca-AEP has been shown to help maintain cell membrane integrity and improve cellular functions.

Multiple choice

Which of the following statements does NOT characterises the digestion of triglycerides in humans?

  1. Fats are emulsified by bile salts.

  2. Fatty acids and glycerol are lipid soluble.

  3. In the epithelial cells of the ileum triglycerides are re-synthesised and forms chylomicrons.

  4. Pancreatic lipase enzymes digest triglycerides to fatty acids and glycerol in the jejunum.

  5. The chylomicrons are carried through the lymphatic system to enter the bloodstream.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Pancreatic lipase enzymes digest triglycerides to fatty acids and glycerol in the duodenum.

Multiple choice

Which of the following acids is not saturated?

  1. Lauric acid

  2. Oleic acid

  3. Palmitic acid

  4. Stearic acid

  5. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This option is correct because it is derived from the olive oil. It contains the 18-carbon atom which adjusts carbon to the carbon double bond and hence, it is known as an unsaturated fatty acid. The formula is CH3(CH2)7HC=CH(CH2)7COOH.

Multiple choice

In maize grains, aleurone layer

  1. has fats

  2. is proteinaceous

  3. has carbohydrates

  4. has sporopollenin
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The aleurone layer in maize grains is a specialized layer of cells rich in proteins, which are used during germination.

Multiple choice

The dietary lipids inside the body are catalysed by

  1. Cholinesterase

  2. Transferase

  3. Lingual lipase

  4. Lysozyme
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Lingual lipase is a member of a family of digestive enzymes called lipases, that use the catalytic triad of Aspartate (Asp), Histidine (His), and Serine (Ser) to hydrolyze long-chain triglycerides into partial glycerides and free fatty acids. The enzyme catalyzes the first reaction in the digestion of dietary lipid, with diglycerides being the primary reaction product.

Multiple choice

The reaction between fats and alkali is known as

  1. Oxidation

  2. Carbonisation

  3. saponification

  4. hydrogenation
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Saponification is the chemical reaction between a fat (triglyceride) and a strong alkali (like NaOH or KOH) to produce glycerol and soap.