Free Characteristics of Enzymes MCQs with Answers
80 Characteristics of Enzymes MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Enzymes are globular biological catalysts that lower activation energy without being consumed, usually showing specificity for particular substrates. Questions cover active sites, enzyme substrate complexes, the lock and key and induced fit models, intracellular and extracellular action, and the effects of denaturation, while distinguishing enzymes from non biological catalysts.
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80 questions · page 3 of 4
- A. Carbohydrates
- B. Lipids
- C. Proteins
- D. Nucleic acids
Explanation: Almost every enzyme is a globular protein whose precisely folded tertiary structure creates the active site, which is why heat and extreme…
Correct answer: Proteins- A. lipid
- B. protein
- C. inorganic ion
- D. vitamin
Explanation: Many coenzymes are organic, non-protein helpers derived from vitamins, and they assist enzymes by carrying electrons or chemical groups…
Correct answer: vitamin- A. Jons Jacob Berzelius
- B. Anselme Payen
- C. Walter Bradford Cannon
- D. None of these
Explanation: Anselme Payen and Jean-François Persoz discovered diastase, one of the first recognized enzymes, in 1833.
Correct answer: Anselme Payen- A. only once
- B. only few times
- C. again and again
- D. non of above
Explanation: A coenzyme functions as an organic helper molecule and is usually regenerated or transferred back to its original form during enzyme…
Correct answer: again and again- A. Rate of digestion
- B. Rate of reaction
- C. Level of pH
- D. Number of active sites
Explanation: Enzyme activity is measured by how quickly substrate is converted into product, which is expressed as the rate of reaction.
Correct answer: Rate of reaction- A. Decarboxylase
- B. Hydrolase
- C. Oxidoreductase
- D. Transferase
Explanation: Hydrolases break chemical bonds by adding water, so a dipeptidase hydrolyses the peptide bond and releases two amino acids.
Correct answer: Hydrolase- A. 27?C
- B. 37?C
- C. 47?C
- D. 30?C
Explanation: Most human enzymes have an optimum temperature close to normal body temperature, about 37 °C, where enzyme-substrate collisions and…
Correct answer: 37?C- A. Some of them consist solely of protein with no non protein part.
- B. They catalyze a chemical reaction without being utilized.
- C. All enzymes are fibrous Proteins.
- D. They without their cofactor are called apoenzyme.
Explanation: Enzymes are generally globular proteins, not fibrous proteins, because their folded three-dimensional structure creates the active site.
Correct answer: All enzymes are fibrous Proteins.- A. Prosthetic group
- B. Coenzyme
- C. Activator
- D. Cofactor
Explanation: A detachable inorganic ion that assists enzyme activity is called an activator, such as Mg2+ or Zn2+.
Correct answer: Activator- A. Cofactor
- B. Coenzymes
- C. Activator
- D. Enzymes
Explanation: Enzymes are biological catalysts, usually proteins, that speed biochemical reactions by lowering activation energy and remain chemically…
Correct answer: Enzymes- A. Vitamins
- B. Carbohydrates
- C. Proteins
- D. Metals
Explanation: Many coenzymes are derived from vitamins, especially B-group vitamins, which are converted into active coenzyme forms that carry electrons…
Correct answer: Vitamins- A. Increases
- B. Decreases
- C. Does not effect
- D. Increases or decreases depending upon individual enzyme
Explanation: Enzymes decrease activation energy by providing an alternative reaction pathway, allowing more molecules to react at a given temperature.
Correct answer: Decreases- A. bio catalyst
- B. hormone
- C. Gland
- D. None of these
Explanation: An enzyme is a biological catalyst, meaning it speeds up a biochemical reaction by lowering its activation energy without being…
Correct answer: bio catalyst- A. derived from vitamins.
- B. composed of amino acids.
- C. loosely attached to enzymes.
- D. covalently attached to enzymes.
Explanation: Prosthetic groups are non-protein molecules that are covalently attached to an enzyme, making them a permanent part of the enzyme's…
Correct answer: covalently attached to enzymes.- A. Lyases
- B. Ligases
- C. Isomerases
- D. Transferases
Explanation: Lyases are a class of enzymes that catalyze the non-hydrolytic removal or addition of groups to substrates, often resulting in the…
Correct answer: Lyases- A. Lyases
- B. Ligases
- C. Hydrolases
- D. Isomerases
Explanation: The correct answer is ligases. RNA polymerase catalyzes the formation of phosphodiester bonds between RNA nucleotides, which is…
Correct answer: Ligases- A. oxidoreductases
- B. Hydrolases
- C. Transferases
- D. lyases
Explanation: These enzymes catalyze the transfer of specific functional group other than hydrogen from one substrate to another.
Correct answer: Transferases- A. Substrate
- B. Coenzyme
- C. Apoenzyme
- D. Holoenzyme
Explanation: An activated enzyme made of a polypeptide chain and a cofactor is referred to as a "holoenzyme." The holoenzyme is the complete…
Correct answer: Holoenzyme- A. Isoenzyme
- B. Coenzyme
- C. Holoenzyme
- D. Apoenzyme
Explanation: The correct term for an organic substance bound to an enzyme and essential for its activity is a "coenzyme." A coenzyme is a non-protein…
Correct answer: Coenzyme- A. Coenzyme
- B. Prosthetic group
- C. Holoenzyme
- D. Activator
Explanation: The detachable cofactor is known as an activator if it is an inorganic ion.
Correct answer: Activator