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. Cholesterol, Guanine
- B. Amino acid NH-2
- C. Nucleotide:Adenine
- D. Nucleoside: Uracil
Explanation: The given structure corresponds with the structure of ribose sugar. As it lacks a phosphoric acid it cannot be a nucleotide and is hence a…
Correct answer: Nucleoside: Uracil- A. Lactose
- B. Glycogen
- C. Starch
- D. Fructose
Explanation: Glycogen and starch are examples of polysaccharides while fructose is an example of monosaccharide.
Correct answer: Lactose- A. Primary structure
- B. Tertiary structure
- C. Secondary structure
- D. Quaternary structure
Explanation: The primary structure of a protein refers to the linear sequence of amino acids along the polypeptide chain.
Correct answer: Primary structure- A. tRNA
- B. rRNA
- C. mRNA
- D. Ribozyme
Explanation: Ribozyme is the only enzyme made of RNA.
Correct answer: Ribozyme- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: B is correct. As both show reversible inhibition, so X must be competitive because it is binding to the active site whereas Y must be…
Correct answer: Option B- A. Acetic acid
- B. Butyric acid
- C. Palmitic acid
- D. Oleic acid
Explanation: Palmitic acid C16H32O2 is a 16 carbon saturated fatty acid as it has no double bonds.
Correct answer: Palmitic acid- A. Palmitic acid
- B. Linoleic acid
- C. Oleic acid
- D. Erucic acid
Explanation: Acetic acid, butyric acid, palmitic acid and stearic acid are some examples of saturated fatty acid
Correct answer: Palmitic acid- A. Erythrose
- B. Ribulose
- C. Heptose
- D. Ribose
Explanation: "The explanation for this question will be added soon!".This is the correct option because deoxyribose is ribose sugarwhich is oxygen…
Correct answer: Ribose- A. Oxalosuccinate
- B. Linolenic acid
- C. Oleic acid
- D. α -ketoglutarate
Explanation: Oleic acid is a monounsaturated fatty acid belonging to the omega-9 fatty acid family.
Correct answer: Oleic acid990. Holoenzyme is?
- A. Protein moiety of enzyme
- B. Non-protein moiety of enzyme
- C. Complete enzyme
- D. Inactive enzyme
Explanation: Holoenzyme is a complete, functional enzyme, which is catalytically active. It consists of an Apoenzyme and a Cofactor.
Correct answer: Complete enzyme- A. Hydrogen
- B. Copper
- C. Oxygen
- D. Carbon
Explanation: Copper is a chemical element with the symbol Cu and atomic number 29. It is a transition metal with a reddish-brown color, and it is known…
Correct answer: Copper- A. Coordinated catabolic activities
- B. Coordinated anabolic activities
- C. Both catabolic and anabolic activities
- D. None of these
Explanation: The correct answer is that the interconversion of carbohydrates, proteins, and lipids in living cells involves both coordinated catabolic…
Correct answer: Both catabolic and anabolic activities- A. Chemistry
- B. Molecular Biology
- C. Biochemistry
- D. Both A and B
Explanation: The correct answer is biochemistry. Biochemistry is the branch of science concerned with the chemical and physicochemical processes and…
Correct answer: Biochemistry- A. Brain
- B. Bone
- C. Blood
- D. Liver
Explanation: The correct answer is the brain, which is composed of approximately 85% water.
Correct answer: Brain- A. 15%
- B. 18%
- C. 50%
- D. 70%
Explanation: The correct answer is 70%. Bacterial cells, like most living cells, contain a high percentage of water.
Correct answer: 70%- A. Pyranose
- B. Furanose
- C. Dextrorotatory
- D. Levorotatory
Explanation: The correct answer is furanose because it describes a sugar with a five-cornered ring structure, similar to the heterocyclic compound…
Correct answer: Furanose- A. Carbon
- B. Hydrogen
- C. Nitrogen
- D. Oxygen
Explanation: Carbohydrates are organic molecules that consist of carbon, hydrogen, and oxygen atoms, usually with a hydrogen:oxygen atom ratio of 2:1…
Correct answer: Nitrogen- A. Oxygen
- B. Nitrogen
- C. Hydrogen
- D. Carbon
Explanation: The correct answer is carbon. Carbon is unique in its ability to form stable covalent bonds with other elements, including itself, which…
Correct answer: Carbon- A. Starch
- B. Cellulose
- C. Glucose
- D. Maltose
Explanation: The correct answer is cellulose. Cellulose is the most abundant carbohydrate because it is a key structural component in the cell walls of…
Correct answer: Cellulose- A. Dates
- B. Amylase
- C. Glycogen
- D. Cellulose
Explanation: Glucose is a simple sugar that naturally occurs in its free state in many fruits, including dates.
Correct answer: Dates