101. The role of fermentation in regenerating NAD plus is that:
Answer: B. NADH gives its electrons to pyruvate or acetaldehyde so NAD plus returns to glycolysis
Biology Class 11 Unit 4: Bioenergetics MCQs
222 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 5.
Tap an option to check your answer.
102. Aerobic respiration is completed in four phases:
Answer: B. glycolysis, oxidation of pyruvate, Krebs cycle, electron transport chain
103. Glycolysis occurs in the:
Answer: C. cytoplasm
104. The preparatory phase of glycolysis is called the:
Answer: B. investment phase, consuming two ATP
105. The oxidative phase of glycolysis is the:
Answer: C. payoff phase producing ATP and NADH
106. In the first step of glycolysis glucose is phosphorylated by:
Answer: B. hexokinase or glucokinase
107. Glucose-6-phosphate is converted to fructose-6-phosphate by:
Answer: B. phosphohexose isomerase
108. Fructose-6-phosphate becomes fructose-1,6-bisphosphate by:
Answer: B. phosphofructokinase
109. The splitting of fructose-1,6-bisphosphate is catalysed by:
Answer: C. aldolase
110. The splitting produces glyceraldehyde-3-phosphate and:
Answer: B. dihydroxyacetone phosphate
111. Dihydroxyacetone phosphate is converted to G3P by:
Answer: B. phosphotriose isomerase
112. G3P donates hydrogen to NAD plus and accepts inorganic phosphate to form:
Answer: B. 1,3-bisphosphoglycerate
113. The conversion of 1,3-bisphosphoglycerate to 3-phosphoglycerate yields ATP by:
Answer: C. substrate level phosphorylation
114. The enzyme for the conversion of 3-phosphoglycerate to 2-phosphoglycerate is:
Answer: B. phosphoglycerate mutase
115. Dehydration of 2-phosphoglycerate gives:
Answer: B. phosphoenolpyruvate (PEP)
116. The final step of glycolysis to form pyruvate uses the enzyme:
Answer: D. pyruvate kinase
117. The net gain of ATP in glycolysis is:
Answer: B. 2
118. The number of ATP produced directly in glycolysis (gross) is:
Answer: B. 4
119. Pyruvate enters the mitochondrion by:
Answer: C. active transport via pyruvate translocase
120. The link reaction converts pyruvate to:
Answer: D. acetyl CoA
121. The three steps of the link reaction are:
Answer: B. decarboxylation, dehydrogenation, addition of coenzyme A
122. The enzyme complex of the link reaction is:
Answer: B. pyruvate dehydrogenase complex
123. The Krebs cycle takes place in the:
Answer: B. mitochondrial matrix
124. The Krebs cycle was discovered by:
Answer: C. Sir Hans Krebs
125. The Krebs cycle is also called the:
Answer: B. citric acid or TCA cycle
126. The first compound formed in the Krebs cycle is:
Answer: B. citrate
127. Acetyl CoA (2C) combines with oxaloacetate (4C) to form:
Answer: A. a 6-carbon citrate
128. The enzyme that forms citrate is:
Answer: B. citrate synthetase
129. Citrate is converted to isocitrate by:
Answer: B. aconitase
130. Isocitrate is converted to alpha-ketoglutarate by:
Answer: B. oxidative decarboxylation
131. Alpha-ketoglutarate is converted to:
Answer: C. succinyl CoA
132. Substrate level phosphorylation in the Krebs cycle occurs when succinyl CoA is converted to:
Answer: B. succinate
133. In the Krebs cycle succinate is oxidized to fumarate by succinate dehydrogenase and the hydrogen is taken up by:
Answer: C. FAD
134. Fumarate is converted to malate by:
Answer: B. hydration (fumarase)
135. Malate is oxidized to:
Answer: D. oxaloacetate
136. In the Krebs cycle (two turns per glucose) the number of CO2 released is:
Answer: C. 4
137. The outputs of two turns of the Krebs cycle include:
Answer: B. 6 NADH, 2 FADH2, 2 ATP
138. The final acceptor of electrons in the respiratory electron transport chain is:
Answer: C. molecular oxygen
139. The electron transport chain is located in the:
Answer: C. inner mitochondrial membrane
140. Complex I of the ETC is:
Answer: B. NADH-Q reductase (NADH dehydrogenase) with FMN and Fe-S
141. The mobile electron carriers of the ETC are:
Answer: B. coenzyme Q (ubiquinone) and cytochrome c
142. Coenzyme Q (ubiquinone) is:
Answer: B. a small lipid-soluble molecule
143. Cytochromes are:
Answer: B. proteins with iron which gain or lose an electron
144. Cytochrome oxidase complex IV consists of:
Answer: C. cyto-a, cyto-a3 and copper
145. The number of proton pumping sites in the ETC is:
Answer: C. 3
146. The ETC releases energy used to pump:
Answer: B. H plus from the matrix to the intermembrane space
147. Oxidative phosphorylation is the synthesis of ATP using energy liberated during:
Answer: B. oxidation of NADH and FADH2 in the presence of oxygen
148. The enzyme which synthesizes ATP in mitochondria is:
Answer: B. ATP synthetase (ATP synthase)
149. ATP synthase has two parts called:
Answer: B. Fo and F1
150. The Fo part:
Answer: B. is embedded in the membrane and forms the proton channel
About Biology Class 11 Unit 4 MCQs (Federal Board)
These 222 Biology MCQs cover Class 11 Unit 4: Bioenergetics 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 5 pages of 50. Use the Print button to save this chapter as a PDF.