Free Biological Molecules MCQs with Answers

• A. Transfer RNA (tRNA)
• B. Ribosomal RNA (rRNA)
• C. Messenger RNA (mRNA)
• D. DNA

Explanation: mRNA carries the genetic instructions from DNA to the ribosome, where it directs the sequence of amino acids in protein synthesis.

• A. Oils
• B. Waxes
• C. Phenols
• D. Fats

Explanation: Oils are typically liquid at room temperature and contain a higher proportion of unsaturated fatty acids.

• A. Acylglycerols
• B. Isoprenoids
• C. Phospholipids
• D. Ketones

Explanation: Terpenoids (also called isoprenoids) are a large group of natural compounds made up of repeating units of isoprene (a 5-carbon structure).

• A. -8 °C
• B. 8oC
• C. 63.1oC
• D. 56 °C

Explanation: Palmitic acid is a saturated long-chain fatty acid with 16 carbon atoms.

• A. Lyxose
• B. Ribose
• C. Xylose
• D. Glucose

Explanation: Ribose is a 5-carbon sugar that is an essential component of RNA, which is abundant in heart muscle due to its high energy demands.

• A. α D-Glucose
• B. α L-Glucose
• C. β D-Glucose
• D. β L-Glucose

Explanation: Cellulose is a polymer of β-D-Glucose units linked by β-1,4- glycosidic bonds.

• A. Water
• B. Carbohydrate
• C. Lipid
• D. Protein

Explanation: Lipids, such as oils and fats, act as natural lubricants in the body. They reduce friction between tissues, protect organs, and help in…

• A. Lipoglycans
• B. D-glucosamine
• C. Keratin sulphate and chondroitin sulphate
• D. N-acetyl glucosamine

Explanation: The exoskeleton of arthropods is made of chitin, a polysaccharide formed by the polymerisation of N-acetyl glucosamine.

• A. 15%
• B. 18%
• C. 50%
• D. 70%

Explanation: Like most living cells, bacterial cells contain a high amount of water, making up about 70% of their total composition.

• A. Glycosidic bonds
• B. Peptide bonds
• C. Hydrogen bonds
• D. Disulphide bonds

Explanation: A peptide bond is a covalent chemical bond formed between two amino acid molecules.

• A. 6
• B. 4
• C. 5
• D. 3

Explanation: Ribulose is known as a pentose sugar, indicating it contains 5 carbon atoms.

• A. A: 3
• B. B: 6
• C. C: 9
• D. D: 12

Explanation: There are 9 water-soluble vitamins.1.Vitamin C2.Vitamin B1 (Thiamine)3.Vitamin B2 (Riboflavin)4.Vitamin B3 (Niacin)5.Vitamin B5…

• A. Intestine
• B. Liver
• C. Macrophages
• D. Both A and B

Explanation: Both the liver and intestines are involved in the synthesis of HDL. The liver produces HDL particles which are secreted into the…

• A. Adenine
• B. Cytosine
• C. Phosphate
• D. Thymine

Explanation: Thymine is a nitrogenous base found in DNA but not in RNA. In RNA, Thymine is replaced by Uracil.

• A. One glycerol and one fatty acid molecule
• B. Three glycerol and three fatty acid molecules
• C. Three glycerol molecules and one fatty acid molecule
• D. One glycerol and three fatty acid molecules.

Explanation: Neutral or true fats are triglycerides that are formed by esterification of three molecules of fatty acids with one molecule of trihydric…

• A. Lecithin - A component of cell membranes
• B. Adenine - A nucleotide that makes up nucleic acids
• C. Triglyceride - Major source of energy
• D. Uracil - A component of DNA

Explanation: The correct answer is A: Lecithin. Lecithin is a phospholipid that is essential for the structure and functionality of cell membranes…

• A. Thymine
• B. Uracil
• C. Cytosine
• D. Guanine

Explanation: Uracil is the correct answer as it is the pyrimidine base that is unique to RNA.

• A. mineral salts
• B. fatty acids
• C. volatile acids
• D. a­ketoglutaric acid

Explanation: The correct answer is a­ketoglutaric acid. A-ketoglutaric acid plays a crucial role in the Krebs cycle, where it serves as an…

• A. 170
• B. 20
• C. 25
• D. 3000

Explanation: About 170 types of amino acids have been found to occur in cells and tissues. Of these, about 25 are constituents of proteins.

• A. Alanine
• B. Serine
• C. Ethanolamine
• D. Aspartic acid

Explanation: Glycine is the simplest amino acid, having a hydrogen atom as its side chain.