🧬 Biochemistry Solved MCQs with Answers

Practice 1490 approved 🧬 Biochemistry questions with verified answers from the 🧬 Medical Science subject for Pakistan exams.

1490 solved MCQs

Standard redox potential for a substance is measured under standard condition and is expressed asAnswer: Volt Most of the enzymes of the citric acid cycle in a eukaryotic cell are located in theAnswer: Mitochondrial matrix A positive redox potential means substance hasAnswer: Higher affinity for electron The end product of glycolysis is pyruvate, which enters the citric acid cycle after being converted toAnswer: Acetyl-CoA Energy that is released from glucose during respiration but not transferred to ATP bonds can be detected asAnswer: Heat Which of the following is involved in energy production?Answer: All of the above Which of the following enzyme does not take part in the TCA cycle?Answer: Pyruvate dehydrogenase The first intermediate in TCA cycle isAnswer: Citrate Cholesterol can be synthesized de novo inAnswer: Liver Which one of the following is not the intermediate of Kreb's cycle?Answer: Stearate Which one is not the main protein in electron transport chain?Answer: Citrate synthease How many ATPs are produced during citric acid cycle?Answer: 12 The FADH₂ and NADH produced by the oxidation of one acetyl-CoA results in the synthesis of about-Answer: 11 ATPs In eukaryotes, electron transport occurs inAnswer: Membranes and mitochondria The catabolism of sugars and fatty acids is similar becauseAnswer: Both of these compounds are funnelled through the TC A/citric acid cycle Membrane potential and the proton gradientAnswer: Are both required to make ATP The irreversibility of the thiokinase reactions (formation of initial acyl-CoA)Answer: Both (a) and (b) Long-chain fatty acids are oxidized step-wise in one carbon units starting from theAnswer: Carboxyl end How many molecules of acetyl-CoA are produced in oxidation of palmitic acid (C₁₆), which involves seven rounds of oxidation?Answer: 8 The oxidation of methanol (wood alcohol) in human retina tissue leads directly to the formation ofAnswer: Formaldehyde The maximum energy per gram on oxidization is yielded fromAnswer: Fat Each cycle of β-oxidation producesAnswer: 1 FADH₂, 1 NAD⁺, and 1 acetyl-CoA The three identical b subunits of the F1, complex during ATP synthesis haveAnswer: Different affinities for ATP and for ADP Where the acyl-CoA formed in the cytosol is transported for oxidation?Answer: Mitochondrial matrix The transport of acyl-CoA for oxidation using a shuttle involves formation of the intermediateAnswer: Acyl-carnitine The key enzyme in the regulation of fatty acid synthesis isAnswer: Acetyl CoA carboxylase Arachidonate has 20 carbon atoms withAnswer: 4 double bonds In the intestine, the dietary fats are hydrolysed byAnswer: Pancreatic lipase HDLs are synthesized inAnswer: Liver Triacylglycerols areAnswer: Insoluble in water