All Free Biology MCQs with Answers

• A. Nitriles, ester
• B. Nitriles, amines
• C. AIkenes, alkynes
• D. Esters, alcohol

Explanation: Explanation for this question has been added!

• A. Polarity of carbonyl group
• B. Due to methyl group
• C. Due to H-bonding
• D. Due London forces

Explanation: Explanation for this question has been added!

• A. Coagulation
• B. Dehydration
• C. Denaturation
• D. None of these

Explanation: The disruption of protein structure by heating, chemical agents, or other factors is commonly referred to as denaturation.Denaturation involves the alteration or unfolding of the native three-dimensional structure of a protein, leading to loss of its biological activity and function. Various factors, including high temperature, changes in pH, exposure to organic solvents, and certain chemicals, can cause denaturation by disrupting the non-covalent interactions (such as hydrogen bonds, hydrophobic interactions, and electrostatic interactions) that maintain the protein's folded structure.

• A. Reducers
• B. Activators
• C. Promotors
• D. Inhibitors

Explanation: Substances that reduce the activity of enzyme action are called enzyme inhibitors.Enzyme inhibitors are molecules that bind to enzymes and interfere with their normal function, often by either slowing down the enzyme's catalytic activity or completely blocking it. Enzyme inhibitors can have various mechanisms of action, including competitive inhibition, non-competitive inhibition, and uncompetitive inhibition, among others.

• A. Carbohydrates
• B. Lipids
• C. Proteins
• D. DNA

Explanation: High molecular mass organic compounds that, upon hydrolysis, yield amino acids are called proteins.Proteins are macromolecules composed of amino acid monomers linked together by peptide bonds. They play essential roles in various biological processes, including enzyme catalysis, cell structure, immune responses, and more. When proteins undergo hydrolysis, the peptide bonds between amino acids are broken, and the resulting products are individual amino acids.

• A. Transport proteins
• B. Structural proteins
• C. Genetic proteins
• D. Regulatory proteins

Explanation: Nucleoproteins are Genetic proteins.Nucleoproteins are complex molecules composed of both nucleic acids (such as DNA or RNA) and proteins. In the context of genetic material and heredity, nucleoproteins are primarily involved in the packaging, organization, and protection of the genetic material (DNA) in cells. They help maintain the structure of chromosomes, regulate gene expression, and facilitate processes such as DNA replication, transcription, and translation.

• A. CO
• B. CH3COOCH3
• C. CH3CH2COOH
• D. CH3COOCH2CH3

Explanation: The reaction of an alcohol with an acid in the presence of conc. H2SO4 to form an ester is called an esterification reaction. The reaction of Ethyl alcohol and Acetic acid in the presence of conc. H2SO4 forms Ethyl acetate.

• A. Methyl MgBr reacts with CO2
• B. Isopropyl MgBr reacts with CO2
• C. Ethyl MgBr reacts with CO2
• D. Propyl MgBr reacts with CO2

Explanation: Ethyl magnesium bromide is an organometallic compound that reacts with carbon dioxide (CO2) through a Grignard reaction. The ethyl group (-CH2CH3) from ethyl magnesium bromide becomes incorporated into the formed carboxylic acid.

• A. Decreases with increase of volume
• B. Decreases with increase in molecular mass
• C. Increases with increase in molecular mass
• D. None of these

Explanation: This option is generally correct. The solubility of carboxylic acids tends to decrease as the molecular mass of the carboxylic acid increases. This is because larger molecules have stronger intermolecular forces (such as van der Waals forces) that can make it more difficult for them to dissolve in a solvent. Smaller carboxylic acids with lower molecular masses are usually more soluble in water or other polar solvents.

• A. colourless liquid, has odour, sour taste
• B. Bright colour bitter taste
• C. Colourless solid, sour taste. pungent smell
• D. All are incorrect

Explanation: Explanation for this question will be added soon!