Free Classification of Biological Molecules MCQs with Answers
154 Classification of 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.
Biological molecules are classified as carbohydrates, lipids, proteins and nucleic acids, with water, minerals and vitamins also supporting cellular processes. The key distinctions involve their monomers, chemical bonds, structures and functions, including glucose and starch, fatty acids and triglycerides, amino acids and polypeptides, and nucleotides in DNA and RNA.
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154 questions · page 7 of 8
- A. Monovalent
- B. Divalent
- C. Trivalent
- D. Tetravalent
Explanation: Carbon is tetravalent because it has four electrons in its outer shell and can form four covalent bonds.
Correct answer: Tetravalent- A. CO2
- B. Water
- C. Lipids
- D. HCI
Explanation: Lipids are organic compounds because they contain carbon-based structures and are produced by living organisms.
Correct answer: Lipids123. Which chemical component has the greatest contribution in the total mammalian cell weight__________?
- A. Proteins
- B. Carbohydrate
- C. Lipids
- D. Water
Explanation: Water usually makes up the greatest proportion of a mammalian cell's mass, commonly about 70% or more, and acts as the main solvent for…
Correct answer: Water- A. Chemistry
- B. Biochemistry
- C. Molocular biology
- D. Both a and b
Explanation: Biochemistry studies the chemical substances and chemical processes occurring in living organisms, including metabolism and the structure…
Correct answer: Biochemistry125. Which chemical component has the same % in bacterial as well as the mammalian cell_____________?
- A. Water
- B. Carbohydrate
- C. Proteins
- D. Lipids
Explanation: Water forms approximately 70% of the mass of both typical bacterial and mammalian cells, although the exact percentage varies with cell…
Correct answer: Water- A. Oxygen
- B. Hydrogen
- C. Sulphur
- D. Carbon
Explanation: Carbon is the basic element of organic compounds because its four covalent bonds allow it to form stable, diverse molecular skeletons.
Correct answer: Carbon- A. Ionic bond
- B. Hydrogen bond
- C. Covalent bond
- D. Electrovalent bond
Explanation: A covalent bond forms when atoms share one or more pairs of electrons to complete or stabilize their outer electron shells.
Correct answer: Covalent bond- A. Inorganic
- B. Cationic
- C. Anionic
- D. Organic
Explanation: Chlorophyll is an organic molecule because it is a carbon-based pigment with a complex ring structure and a magnesium ion at its centre.
Correct answer: Organic- A. Hydration
- B. Hydrolysis
- C. Dehydration synthesis
- D. Electrolysis
Explanation: Hydrolysis uses water to break a covalent bond in a large molecule, such as splitting a polymer into smaller units.
Correct answer: Hydrolysis- A. Molecular biology
- B. Physiology
- C. Biochemistry
- D. Atomic biology
Explanation: Biochemistry studies the chemical substances present in living organisms and the reactions they undergo, including metabolism and enzyme…
Correct answer: Biochemistry- A. Polysaccharide
- B. Protein
- C. Hemoglobin
- D. ATP
Explanation: ATP is a micromolecule because it is a relatively small molecule made of adenine, ribose and phosphate groups, although it transfers…
Correct answer: ATP- A. Cell nucleus
- B. DNA or RNA
- C. Cell membrane
- D. Vacuole
Explanation: All cellular living organisms contain genetic material, with DNA serving as the hereditary material and RNA functioning in gene…
Correct answer: DNA or RNA- A. Two ionic bonds
- B. Four ionic bonds
- C. Four covalent bonds
- D. Two hydrogen bonds
Explanation: Carbon is unique in its ability to form four covalent bonds, allowing it to be the backbone of complex organic molecules.
Correct answer: Four covalent bonds- A. Oxygen
- B. Carbon
- C. Hydrogen
- D. Nitrogen
Explanation: Carbon is the second most abundant element in the human body, accounting for 18% of body weight.
Correct answer: Carbon- A. Protein
- B. Water
- C. DNA
- D. RNA
Explanation: The correct answer is RNA. In a mammalian cell, RNA makes up about 1.1% of the cell's total mass, reflecting its role in protein synthesis…
Correct answer: RNA- A. Hydroxyl group
- B. Hydrogen
- C. Water
- D. Nitrogen
Explanation: Polymers are broken down into monomers via hydrolysis reactions, in which a bond is broken, or lysed, by addition of a water molecule.
Correct answer: Water- A. Hooves
- B. Haemoglobin
- C. Enzymes
- D. Steroids
Explanation: One major class of lipids is the steroids, which have structures totally different from the other classes of lipids.
Correct answer: Steroids- A. Two covalent bonds are formed
- B. Hydrogen bond is formed
- C. Single covalent bond is formed
- D. Ionic bond is formed
Explanation: Option A is incorrect because Two covalent bonds are formed by the sharing of two electron pairs.Option B is incorrect because Hydrogen…
Correct answer: Single covalent bond is formed- A. 3
- B. 6
- C. 9
- D. 12
Explanation: The correct answer is Option C: 9. The water-soluble vitamins include the B-complex vitamins and Vitamin C.
Correct answer: 9- A. Amino acids
- B. Nucleotides
- C. Citric acids
- D. Isoprenoid units
Explanation: b) Nucleotides:This is the correct answer. Nucleic acids, such as DNA (deoxyribonucleic acid) and RNA (ribonucleic acid), are made up of…
Correct answer: Nucleotides