101. RNases digest RNA into:
Answer: B. ribonucleotides
Biology Class 11 Unit 3: Enzymes MCQs
146 multiple choice questions with the correct answer for each. Tap an option to check yourself, or switch on "Show all answers". This is page 3 of 3.
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102. DNases digest DNA into:
Answer: B. deoxyribonucleotides
103. ATPases cause hydrolysis of:
Answer: C. ATP
104. Enzymes are named by adding "ase" to the name of the:
Answer: C. substrate
105. The enzyme lipase digests:
Answer: C. fats
106. A diagnostic enzyme for damage to the pancreas is:
Answer: B. lipase
107. Creatine phosphokinase is used to detect damage to:
Answer: C. muscle cells
108. Gamma-glutamyl transpeptidase is used to assess:
Answer: B. liver function
109. Snake venom inhibits the enzyme:
Answer: B. cholinesterase
110. Venom that acts on the nervous system and the brain is:
Answer: B. neurotoxic
111. Venom acting locally at the bite site is:
Answer: C. cytotoxic
112. Immobilized lactase in sodium alginate beads is used to make:
Answer: B. lactose-free milk
113. Alginate beads for immobilizing enzymes are hardened in:
Answer: B. calcium chloride solution
114. Benedict's test on lactose-free milk detects:
Answer: B. reducing sugars galactose and glucose
115. Which enzyme works in a protein digestion at the very last step converting dipeptides into amino acids?
Answer: C. Erypsin
116. The molecule on which an enzyme acts is called:
Answer: C. substrate
117. An enzyme added to a solution at equilibrium would:
Answer: C. change nothing, the reaction stays at equilibrium
118. A key feature of an allosteric site is that it is often involved in:
Answer: B. feedback inhibition
119. Many enzymes are secreted in an inactive form to protect:
Answer: C. cell proteins
120. The specificity of an enzyme is due to its:
Answer: C. surface configuration of the active site
121. Salivary amylase activity decreases when chloride ions are reduced because chloride ions are:
Answer: B. cofactors (activators)
122. Enzymes change the rate of a reaction by:
Answer: D. bringing the reacting molecules into a precise orientation and lowering activation energy
123. The boiled enzyme failed because it was:
Answer: B. denatured
124. The enzyme in the ice bath was:
Answer: C. inactivated only
125. The bonds disrupted first by heating are the:
Answer: B. hydrogen bonds
126. The optimum temperature for this human enzyme is about:
Answer: C. 37 degrees
127. The enzyme is most likely:
Answer: B. pepsin
128. The rate falls at pH 8 because:
Answer: B. charges on amino acids change and the enzyme shape is altered
129. The enzyme that works best at pH 8 is:
Answer: B. trypsin
130. The enzyme is secreted in the stomach as:
Answer: B. pepsinogen
131. The poison is most likely:
Answer: B. cyanide
132. This is an example of:
Answer: B. non-competitive (irreversible) inhibition
133. Iron in cytochrome oxidase belongs to the:
Answer: C. prosthetic group
134. Increasing substrate concentration will:
Answer: B. not overcome this inhibition
135. Malonate acts as a:
Answer: B. competitive inhibitor
136. Malonate resembles the substrate in:
Answer: B. structure
137. The recovery is because succinate:
Answer: B. outcompetes malonate for the active site
138. This type of inhibition supports the:
Answer: B. lock and key hypothesis
139. This is an example of:
Answer: B. feedback inhibition
140. Threonine binds to the:
Answer: B. allosteric site of enzyme 1
141. When threonine is used up, the pathway:
Answer: B. resumes activity
142. Threonine is the:
Answer: C. end product
143. The enzyme splits lactose into:
Answer: B. galactose and glucose
144. Immobilized enzymes are advantageous because they can be:
Answer: B. separated from the product and reused
145. The bead hardening solution is:
Answer: B. CaCl2
146. Lactase belongs to the class:
Answer: B. hydrolases
About Biology Class 11 Unit 3 MCQs (Federal Board)
These 146 Biology MCQs cover Class 11 Unit 3: Enzymes of the Federal Board (FBISE) HSSC-I (1st Year / Class 11) syllabus. They are SLO-based MCQs as per the new pattern for FBISE exams. Each question has four options and the correct answer is shown, so you can practise for the annual examination and find the topics you still need to revise. The questions are split over 3 pages of 50. Use the Print button to save this chapter as a PDF.