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. Primary structure
- B. Secondary structure
- C. Tertiary structure
- D. Quaternary structure
Explanation: A peptide bond is made up of many amino acids condensing to form peptide bonds.
Correct answer: Primary structure- A. Concentration of products
- B. Time
- C. Concentration of substrate
- D. Concentration of solvent
Explanation: The more the substrate, there is a higher chance that they will collide with the active sites of the enzymes and hence, the greater the…
Correct answer: Concentration of substrate- A. Lyases
- B. Hydrolases
- C. Ligases
- D. Transferases
Explanation: Lyases are the enzymes responsible for catalyzing addition and elimination reactions.
Correct answer: Lyases- A. Sulfur
- B. Carbon
- C. Nitrogen
- D. Oxygen
Explanation: Chemically, proteins are complex nitrogenous organic compounds, which are associated with the concept of life itself.
Correct answer: Nitrogen1165. Enzymes are _ in nature?
- A. Proteins
- B. Carbohydrates
- C. Lipids
- D. Nucleic acid
Explanation: The enzyme is a complex organic substance, which altered the rate of an already initiated biological reaction without itself being altered…
Correct answer: Proteins- A. Dipeptide
- B. Protein
- C. Polypeptide
- D. Peptide
Explanation: OPTION A: When two amino acids are joined together, a dipeptide is formed.
Correct answer: Polypeptide- A. Maximum temperature
- B. Absolute temperature
- C. Critical temperature
- D. Optimum temperature
Explanation: Option B : Absolute temperature is temperature measured using the Kelvin scale where zero is absolute zero.
Correct answer: Optimum temperature- A. Oxidoreductases
- B. Hydrolases
- C. Ligases
- D. Transferases
Explanation: Option: A A dehydrogenase is an enzyme belonging to the group of oxidoreductases that oxidizes a substrate by reducing an electron…
Correct answer: Oxidoreductases- A. Reaction site
- B. Active site
- C. Binding site
- D. None of these
Explanation: The active site is the region of an enzyme where substrate molecules bind and undergo a chemical reaction.
Correct answer: Active site- A. Coenzyme
- B. Cofactor
- C. Apo-enzyme
- D. Prosthetic group
Explanation: Apoenzyme or apoprotein is an enzymatically inactive protein part of an enzyme, which requires a cofactor for its activity.
Correct answer: Apo-enzyme- A. Activator
- B. Coenzyme
- C. Co-factor
- D. Both A and B
Explanation: Following are definitions of each of the above terms: Coenzyme: A substance that enhances the action of an enzyme.
Correct answer: Both A and B1172. The most abundant protein in animals, forming 25%-35% of body protein, is which type of protein?
- A. Simple proteins
- B. Conjugated proteins
- C. Derived proteins
- D. None of these options are correct
Explanation: 'Simple proteins' are those that are made of amino acid units only, joined by peptide bonds.
Correct answer: Simple proteins- A. Amylase
- B. Urease
- C. Pectin
- D. None
Explanation: Is correct as it is a fact as urease is involved in hydrolysis of urea
Correct answer: Urease- A. Reversible
- B. Irreversible
- C. Condensation
- D. Oxidation
Explanation: Reason: Reactions of enzymes are mostly reversible depending on the extent to which the products differ from the reactants.
Correct answer: Reversible- A. Milk
- B. Eggs
- C. Beans
- D. Muscles
Explanation: Albumin, a water soluble protein, is the primary protein present in egg whites as ovalbumin. Serum albumin is present in the bloodstream.
Correct answer: Eggs- A. It increases the enzyme activity
- B. Stops the reaction
- C. Decreases the enzyme activity
- D. Both b and c
Explanation: At optimum temperature enzymes have maximum activity, if the temperature increases further their activity decreases and at very high…
Correct answer: Both b and c- A. Thousands
- B. Millions
- C. Hundreds
- D. Billions
Explanation: Enzymes are macromolecules with mass ranging between millions. This is the exact value from ptb ..it needs to be memorised.
Correct answer: Millions1178. The substance that is attached to the enzyme at specific place and converted into product is called?
- A. Co-factor
- B. Iso-zyme
- C. Active site
- D. Substrate
Explanation: Option D is correct as the "substrate" is attached to the enzyme at a specific site to be broken down.
Correct answer: Substrate- A. Biocatalyst
- B. Autocatalysis
- C. Heterocatalysis
- D. Homocatalysis
Explanation: Option C is correct as catalysts are generally foreign substances, but sometimes one of the products formed in a reaction can act as a…
Correct answer: Autocatalysis- A. Invertase
- B. Urease
- C. Glycolysis
- D. None
Explanation: Option A.Sucrose can be hydrolyzed to glucose and fructose by invertase enzyme.
Correct answer: Invertase