MCQs on Coenzyme and Cofactor Quiz Online

MCQs on Coenzyme and Cofactor Quiz Online

Coenzyme and Cofactor – Definition


Enzymes are biological catalysts that can accelerate a specific chemical reaction by lowering the activation energy but remain un-altered in the process. The metal ions which are loosely attached with the enzymes are called cofactors. The non protein, organic molecules that participate in enzyme-catalyzed reactions are called coenzymes.

Table of Content:

  • Cofactors of enzymes
  • Cofactors examples
  • Coenzymes
  • Coenzymes examples

All of these MCQs on “Cofactors and Coenzymes” in Zoology MCQs are preferably for test / interview preparation for BSc, MSc, BS (Hons), NTS, FPSC, PPSC, PTS, CSS, MDCAT, ECAT, MCAT and all other competitive examination for foreign study including overseas students.

Read More: Factors Affecting Enzyme Activity MCQs


Cofactors and Coenzymes MCQs (Quiz Online)


Cofactors of Enzymes:

Q1. When metal ions are loosely attached with the enzymes, they becomes:

  1. Catalysts
  2. Coenzymes
  3. Cofactors
  4. Substrates

Answer: c

Q2. Which change a nonfunctioning active site to a functioning one?

  1. Cofactors
  2. Metal ions
  3. Substrates
  4. None

Answer: b

Q3. The attachment of a cofactor changes the shape of the ______________.

  1. substrate
  2. enzyme
  3. protein
  4. nucleic acid

Answer: c

Q4. Which allows the enzyme to combine with its substrate?

  1. Cofactor
  2. Metal ion
  3. Coenzyme
  4. None

Answer: a

Q5. During enzyme-substrate complex formation, which of the following participate in the temporary bonds between the enzyme and its substrate?

  1. Cofactors
  2. Cofactors of other enzymes
  3. Coenzymes
  4. Metal ions

Answer: b

Q6. The metal ions which are loosely attached with the enzymes include:

  1. Ca2-
  2. Mg2-
  3. Cu2-
  4. All of the above

Answer: d

Cofactors Examples:

Q7. Which cofactor is a vitamin B3 found primarily in edible seeds such as beans, rice, and corn?

  1. Folic acid
  2. Thiamine
  3. Iron-sulfur clusters
  4. none

Answer: b

Q8. Which is a vital part of cofactors and enzymes involved in electron transfer and energy transfer?

  1. Folic acid
  2. Thiamine
  3. Iron-sulfur clusters
  4. none

Answer: c

Q9. Both iron and sulfur are able to store and release electrons with greater eases than more common atoms such as __________.

  1. hydrogen
  2. carbon
  3. oxygen
  4. nitrogen

Answer: b


Read More: MCQs on Compounds and Molecules Multiple Choice Questions and Answers


Q10. Which cofactor is necessary for the body to produce DNA, RNA, and amino acids, which are necessary for growth and cell division?

  1. Folic acid
  2. Vitamin B9
  3. Both a and b
  4. None

Answer: c

Coenzymes:

Q11. Which of the following participates in enzyme-catalyzed reactions?

  1. Cofactor
  2. Coenzymes
  3. Metal ions
  4. None

Answer: b

Q12.  The non protein, organic molecules are:

  1. coenzymes
  2. enzymes
  3. cofactors
  4. all of the above

Answer: a

Q13. Coenzymes are often used in transporting ______________ from one enzyme to another.

  1. chemicals
  2. substrates
  3. electrons
  4. protein molecules

Answer: c


Read More: MCQs on Connective Tissue Questions and Answers


Q14. Electrons transported by coenzymes are present in the form of ______________ atoms.

  1. oxygen
  2. hydrogen
  3. carbon
  4. nitrogen

Answer: b

Q15. In which form, coenzymes transport energy from one enzyme to another?

  1. oxygen atoms
  2. nitrogen atoms
  3. carbon atoms
  4. hydrogen atoms

Answer: d

Coenzymes Examples:

Q16. The vitamins which function as coenzymes are:

  1. niacin
  2. riboflavin
  3. both a and b
  4. none

Answer: c

Q17.Niacin and riboflavin vitamins are used to make coenzymes.              True/False

Answer: True

Q18. One of the most important cofactors in the cell is the hydrogen acceptor (NAD).

Answer: False (coenzymes)

Q19. Nicotinamide adenine dinucleotide (NAD) is made from which vitamin?

  1. Vitamin A
  2. Vitamin B
  3. Vitamin C
  4. Vitamin D

Answer: b

Q20. NAD acquires a hydrogen atom from an enzyme and it reduces to NADH.

Answer: True

Leave a Reply

Your email address will not be published. Required fields are marked *