Free Biological Molecules MCQs with Answers
1,790 Biological Molecules MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
The chapter covers water's polarity and biological roles, carbohydrates, lipids, proteins and nucleic acids, including their monomers, bonds, structures and functions. It also distinguishes RNA from DNA and explains conjugated molecules such as glycoproteins, glycolipids and nucleoproteins, which combine organic molecules with a non-protein component.
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- A. Silk fiber
- B. Myoglobin
- C. Keratin
- D. Fibrin
Explanation: Myoglobin is the correct answer because it is a globular protein, characterized by a compact and spherical structure, in contrast to…
Correct answer: Myoglobin- A. Secondary structure
- B. Primary structure
- C. Quaternary structure
- D. Tertiary structure
Explanation: Haemoglobin has a quaternary structure. It consists of two pairs of different proteins, designated the α and β chains.
Correct answer: Quaternary structure- A. DNA
- B. ATP
- C. RNA
- D. NAD
Explanation: ATP is a single nucleotide. Phosphodiester bond is present between nucleotides.
Correct answer: ATP764. Nucleic acid is:
- A. Monomer and Macromolecule
- B. Polymer and Macromolecule
- C. Monomer and Micromolecule
- D. Polymer and Micromolecule
Explanation: A polymer is a large molecule composed of repeating subunits called monomers.
Correct answer: Polymer and Macromolecule- A. Deoxyribose sugar
- B. Phosphate group
- C. Nitrogenous base
- D. Choline
Explanation: The correct answer is Choline. DNA is composed of nucleotides, which include a deoxyribose sugar, a phosphate group, and a nitrogenous…
Correct answer: Choline- A. Butyric Acid
- B. Oleic Acid
- C. Palmitic Acid
- D. Acetic Acid
Explanation: Correct answer is Oleic Acid as it is a monounsaturated fatty acid.The example of an unsaturated fatty acid among the options provided is…
Correct answer: Oleic Acid- A. Galactose
- B. Glucagon
- C. Glycogen
- D. Glucose
Explanation: Glycogen is the storage form of carbohydrate found in animals. Glycogen is the body's stored form of glucose, which is a type of sugar…
Correct answer: Glycogen768. _ is a disaccharide.
- A. Glucose
- B. Galactose
- C. Fructose
- D. Sucrose
Explanation: A disaccharide is a carbohydrate formed from two monosaccharide units. Sucrose is a disaccharide composed of one glucose unit and one…
Correct answer: Sucrose- A. Water
- B. Lipids
- C. Carbohydrates
- D. Proteins
Explanation: Proteins make up 18% of the cells composition in mammals. You might choose water, as it makes 70% of the cell.
Correct answer: Proteins- A. Starch
- B. Cellulose
- C. Sucrose
- D. Glycogen
Explanation: Starch: Starch is not stored in animal cells. It is a complex polysaccharide and the primary energy storage carbohydrate in plants.
Correct answer: Glycogen- A. Cotton
- B. Chitin
- C. Cellophane
- D. Paper
Explanation: The correct answer is cotton, as it is composed primarily of cellulose with minimal impurities, making it the closest to pure cellulose…
Correct answer: Cotton- A. Lactose
- B. Cellulose
- C. Glucose
- D. Glycogen
Explanation: Lactose: Lactose is a disaccharide composed of one molecule of glucose and one molecule of galactose.
Correct answer: Glycogen773. _ is storage form of carbohydrates in animals and humans which is equivalent to the _ in plants.
- A. Glycogen, Cellulose
- B. Starch, Cellulose
- C. Starch, Glycogen
- D. Glycogen, Starch
Explanation: Glycogen and starch are storage forms of carbohydrates in animals and plants respectively.
Correct answer: Glycogen, Starch- A. Tetroses
- B. Trioses
- C. Pentoses
- D. Hexoses
Explanation: The fundamental building block of nucleic acids is the nucleotide, which comprises three components: a phosphate group, a nitrogenous…
Correct answer: Pentoses- A. Primary structure
- B. Tertiary structure
- C. Secondary structure
- D. Quaternary structure
Explanation: Muscle haemoglobin, known as myoglobin, possesses a tertiary structure.
Correct answer: Tertiary structure- A. Primary
- B. Secondary
- C. Tertiary
- D. Quaternary
- E. Both A and B
Explanation: The most common types of secondary structures are the α helix and the β pleated sheet.
Correct answer: Secondary- A. Hydrophobic interactions
- B. Disulfide bonds
- C. Hydrogen bonds
- D. Ionic bonds
Explanation: Hydrogen bonds are the primary type of bonds required to maintain the alpha helix configuration of a protein.
Correct answer: Hydrogen bonds- A. High proportion of oxygen
- B. Low proportion of carbon
- C. Lower proportion of C-H bonds
- D. High proportion of C-H bonds
Explanation: Option D is correct. Lipids store more energy than carbohydrates primarily because they have a higher proportion of carbon-hydrogen (C-H)…
Correct answer: High proportion of C-H bonds- A. P-O-C-P-O-C
- B. C-O-P-O-C
- C. C-O-P
- D. C-C-O-P
Explanation: The correct answer is Option B: C-O-P-O-C. A phosphodiester bond forms the backbone of DNA and RNA molecules by linking the 5' carbon of…
Correct answer: C-O-P-O-C- A. Fatty acids
- B. Ribonucleic acid
- C. Ascorbic acid
- D. Deoxyribonucleic acid
Explanation: Option B is correct. Yes, ribonucleic acid (RNA) is the constituent of RNA molecules.
Correct answer: Ribonucleic acid