🧬 Biochemistry Solved MCQs with Answers

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

1490 solved MCQs

When concentration of the reactants is higher than the equilibrium concentration thenAnswer: Both (b) and (c) Which of the following is not true of glycolysis?Answer: The pathway oxidizes two moles of NADH to NAD+ for each mole of glucose that enters In glycolysis, ATP is formed by the transfer of a high-energy phosphate from 1,3-bisphosphoglycerate to ADR No such high-energy phosphate donor has ever been isolated in mitochondria becauseAnswer: No such phosphate donor exists ATP is from which general category of molecules?Answer: Nucleotides The glycolytic pathway (glucose → 2 pyruvate) is foundAnswer: In all living organisms Which of the following could act as an uncoupler of electron transport and ATP synthesis?Answer: Both (a) and (b) Which of the following is not a mechanism for altering the flux of metabolites through the rate-determining step of a pathway?Answer: Diffusional coupling between adjacent active sites Phosphofructokinase, the major flux-controlling enzyme of glycolysis is allosterically inhibited and activated respectively byAnswer: ATP and ADP Which of the following regulates glycolysis steps?Answer: All of the above During glycolysis, the major energy generating step involvesAnswer: Glyceraldehyde-3 -dehydrogenase Fructose-2,6-bisphosphateAnswer: Both (b) and (c) Glucose from the breakdown of glycogen is obtained inAnswer: Both (a) and (b) Glycogen hasAnswer: α-1,4 and α-1,6 linkages Fructose is metabolized byAnswer: Both (a) and (b) A common way that cells capture the energy released during the breakdown of large molecules is to add electrons to smaller, specialized molecules that can accept them. This process of electron acceptance is otherwise known asAnswer: Reduction Humans are unable to digestAnswer: Cellulose How many ATP equivalents per mole of glucose input are required for gluconeogenesis?Answer: 6 Which of the following compounds is responsible for coordinated regulation of glucose and glycogen metabolism?Answer: Fructose 2,6 bisphosphate Gluconeogenesis requires a higher amount of ATP equivalents as compared to that produced by glycolysis becauseAnswer: Glycolysis releases energy as heat Which of the following is carried out when cAMP functions as a second messenger?Answer: Activates the cAMP-dependent protein kinase The production or break down of __________ is often coupled with the metabolic reactions of biosynthesis and catabolism.Answer: .ATP The cells dependent solely on glucose as an enrgy source areAnswer: Brain cells The main site for gluconeogenesis isAnswer: Liver Which of the following statements about the energy needs of cells is false?Answer: The most usable energy for cells comes from the rapid combustion of glucose In lysozyme catalysis, which of the following does not contribute?Answer: Formation of a covalent intermediate at Ser195 Cellulose fibers resemble with the protein structure in the form ofAnswer: β-sheets During vigorous exercise, pyruvate produced by glycolysis is converted toAnswer: Lactate Glucagon and epinephrineAnswer: Stimulates gluconeogenesis and inhibits glycolysis The NAG6 substrate is hydrolyzed by human lysozyme to formAnswer: NAG₄ + NAG₂ Gluconeogenesis usesAnswer: 4 ATPs and 2 GTPs per glucose