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.
Last updated
1,790 questions · page 65 of 90
- A. [Enzyme]2
- B. [Enzyme]3
- C. [Enzyme]
- D. [√[Enzyme]]
Explanation: The rate of reaction is directly proportional to the square root of the enzyme concentration, represented as [√[Enzyme]].
Correct answer: [√[Enzyme]]- A. Polar site
- B. Cationic site
- C. Active site
- D. Anionic site
Explanation: This is the correct option. The active site is the specific region on the enzyme where the substrate binds and undergoes the catalytic…
Correct answer: Active site- A. Apoenzyme
- B. Coenzyme
- C. Cofactors
- D. Both B and C
Explanation: The protein component of the enzyme is called apo-enzyme and the non-protein component is called the co-enzyme.
Correct answer: Both B and C- A. Vitamin
- B. Carbohydrate
- C. Lipids
- D. Proteins
Explanation: The group of compounds that is primarily responsible for building of body of an animal and its maintenance is called protein.
Correct answer: Proteins1285. Which enzyme is used to catalyze the addition of ammonia, water or carbon dioxide to double bond?
- A. Phospho-transferase
- B. Phospho-glyceromutases
- C. Fumarase
- D. Succinic thiokinase
Explanation: Option A is correct.Phospho-transferase enzymes are used to catalyze the addition of ammonia, water, or carbon dioxide to double bonds.
Correct answer: Phospho-glyceromutases- A. Fe+2
- B. Zn+2
- C. Mg+2
- D. None of these
Explanation: Option A is correct.The activator for cytochrome oxidase is Fe2+. Cytochrome oxidase is an enzyme that is found in the electron transport…
Correct answer: Fe+21287. Thrombin is used:
- A. For treatment of cancer
- B. Locally to stop bleeding
- C. To diagnose heart disease
- D. For treatment of rickets
Explanation: Option B is correct.Thrombin is used locally to stop bleeding. It is a protein that is produced by the liver and is involved in the…
Correct answer: Locally to stop bleeding- A. Thrombin
- B. LDH-I
- C. L-asparaginase
- D. Alkaline phosphatase
Explanation: Option C is correct.L-asparaginase is a medication that is used to treat acute lymphoblastic leukemia (ALL), a type of cancer that starts…
Correct answer: L-asparaginase- A. Apoenzyme
- B. Coenzyme
- C. Cofactors
- D. Holoenzyme
Explanation: Option A is correct.The protein part of an enzyme is called apoenzyme. The apoenzyme is the inactive form of the enzyme.
Correct answer: Apoenzyme- A. CH3COOH
- B. CICH2COOH
- C. Cl2CHC00H
- D. Cl3CCOOH
Explanation: Option A is correct.The weakest acid among the given options is CH3COOH or acetic acid.
Correct answer: CH3COOH- A. Acid halide
- B. Acid amide
- C. Ester
- D. Acid anhydride
Explanation: Acid amide cannot be prepared by the reaction of a carboxylic acid with ammonia.
Correct answer: Acid amide- A. By the oxidation of alcohol
- B. By acid hydrolysis of alkane nitrite
- C. By the reaction R-Mg-Br with CO2 followed by acid hydrolysis
- D. By the reduction of aldehydes
Explanation: Option D is correct.Aldehydes can be reduced not to carboxylic acids by using a strong reducing agent, such as hydrogen gas and a metal…
Correct answer: By the reduction of aldehydes- A. Dehydration of carboxylic acid with P2O5
- B. Reaction of carboxylic acid with SOCl2
- C. Reaction of carboxylic acid with NH3
- D. Reaction of carboxylic acid with alcohol in the presence of cone. H2SO4
Explanation: Option A is correct.Acid anhydrides can be prepared by the dehydration of two carboxylic acids in the presence of a dehydrating agent.
Correct answer: Dehydration of carboxylic acid with P2O5- A. HCOOH
- B. CH3COOH
- C. CH3CH2COOH
- D. CH3CH2CH2COOH
Explanation: Option A is correct.Formic acid is the simplest carboxylic acid. It has a pKa value of 3.75, which is the lowest among the given acids.
Correct answer: HCOOH- A. FCH2COOH
- B. CICH2COOH
- C. BrCH2COOH
- D. ICH2COOH
Explanation: Fluorine is the most electronegative halogen. The electron-withdrawing effect of fluorine increases the acidity of the carboxylic acid by…
Correct answer: FCH2COOH- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The reaction of acid and alcohol gives ester.
Correct answer: Option D1297. Vinegar has:
- A. 1 to 10 % ethanoic acid
- B. 10 to 20 % ethanoic acid
- C. 100 % ethanoic acid
- D. 30 to 40 % ethanoic acid
Explanation: This range represents the typical concentration of ethanoic acid, or acetic acid, found in vinegar.
Correct answer: 1 to 10 % ethanoic acid- A. Butanoic acid
- B. Propanoic acid
- C. Ethanoic acid
- D. Methanoic acid
Explanation: Rancid butter typically has a smell due to the presence of butanoic acid, also known as butyric acid.
Correct answer: Butanoic acid1299. Carbosylic acids have greater melting and boiling points than alcohols because they have stronger?
- A. Hydrogen bonding
- B. Dispole-dispole forces
- C. Debye forces
- D. Van Der Waals forces
Explanation: Carboxylic acids can form strong hydrogen bonds due to the presence of the carboxyl group (-COOH).
Correct answer: Hydrogen bonding- A. It has planar structure
- B. The bond length C = O is 120 pm
- C. The bond angle of H - C = O is 124o
- D. The bond angle of O - C = O is 120
Explanation: The bond angle of O-C=O in formic acid is indeed approximately 120 degrees.
Correct answer: The bond angle of O - C = O is 120