All Free Biology MCQs with Answers

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19844 questions · page 521 of 1985

5201. Nucleophilic reactions of carboxylic acids are due to the:

Moderate
  • A. Presence of -OH group
  • B. Presence of C-O single bond
  • C. Presence of C-O double bond
  • D. None of these

Explanation: Nucleophilic reaction of carboxylic acids are due to -OH group.

Correct answer: Presence of -OH group

5202. Enzymes are:

Moderate
  • A. Non-specific in action
  • B. Very reactive
  • C. Highly specific
  • D. Volatile

Explanation: Explanation for this question will be added soon!

Correct answer: Highly specific

5203. On reacting with which of the following carboxylic acids produce CO2?

Moderate
  • A. Carbonate
  • B. Bicarbonate
  • C. Bisulphites
  • D. Both A and B

Explanation: Carboxylic acid decomposes carbonates and bicarbonates evolving carbon dioxide gas with effervsescence.

Correct answer: Both A and B

5204. Reduction of ethanoic acid with LiAlH4 produces:

Moderate
  • A. Propanol
  • B. Ethanal
  • C. Ethanol
  • D. Ethane

Explanation: Explanation for this question will be added soon!

Correct answer: Ethanol

5205. Which of the following is an example of tricarboxylic acids?

Moderate
  • A. Maleic acid
  • B. Citric acid
  • C. Butyric acid
  • D. None of these

Explanation: Explanation for this question will be added soon!

Correct answer: Citric acid

5206. Activator of carbonic anhydrase enzyme is:

Moderate
  • A. Mn2+
  • B. Mg2+
  • C. Zn2+
  • D. None of these

Explanation: Explanation for this question will be added soon!

Correct answer: Zn2+

5207. Denaturing of protein is_process:

Moderate
  • A. Reversible
  • B. Irreversible
  • C. Equilibrium
  • D. all of these

Explanation: Explanation for this question will be added soon!

Correct answer: Irreversible

5208. When two carboxylic acids are strongly heated in the presence of P2O5, which product is formed?

Moderate
  • A. Acid halides
  • B. Dimer
  • C. Acid anhydrid
  • D. None of these

Explanation: Explanation for this question will be added soon!

Correct answer: Acid anhydrid

5209. Which of the following evolves carbon dioxide with sodium bicarbonate?

Moderate
  • A. CH3COOO-H3
  • B. CH3CH2OH
  • C. CH3CH2COOH
  • D. CH3COOOCH3

Explanation: Explanation for this question has been added!

Correct answer: CH3CH2COOH

5210. Protein part attached with non-protein part in enzymes belongs to which class of proteins?

Moderate
  • A. Simple
  • B. Conjugated'/compound
  • C. Derived
  • D. All of these

Explanation: Explanation for this question will be added soon!

Correct answer: Conjugated'/compound