🧬 Biochemistry Solved MCQs with Answers

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

1490 solved MCQs

A person with phenylketonuria is advised not to consume which of the following products?Answer: Aspartame Tyrosine is degraded to acetoacetyl CoA and fumarate and is described as aAnswer: Ketogenic and glucogenic amino acid Transaminase enzymes are present inAnswer: Liver A person with phenylketonuria will convertAnswer: Phenylalanine to phenylpyruvate An example of the oxidative deamination isAnswer: glutamate = α-ketoglutarate + NH₃ In the normal breakdown of phenylalanine, it is initially degraded toAnswer: Tyrosine Transamination is the transfer of an aminoAnswer: Group from an amino acid to a keto acid Lysine is degraded to acetoacetyl CoA and is described as aAnswer: Ketogenic amino acid A ketogenic amino acid is one which degrades toAnswer: Either acetyl CoA or acetoacetyl CoA A best described ketogenic amino acid isAnswer: Lysine A person suffering from phenylketonuria on consumption food containing high phenylalanine may lead to the accumulation ofAnswer: Phenylpyruvate How many molecules of ATP are hydrolysed to form two molecule of ammonia?Answer: 16 The nitrogen atoms of urea produced in the urea cycle are derived fromAnswer: Ammonia and aspartic acid The products of urea cycle areAnswer: 1 molecule of fumaric acid, 1 molecule of urea, 1 molecule of AMP, 2 molecules of ADP Nitrate reduction can be carried out byAnswer: Plant and microorganism Which of the following is used as carbon atom source while producing urea in the urea cycle?Answer: Carbon dioxide Which of the following amino acid do not fall under the category of essential amino acid?Answer: Glycine Urea cycle convertsAnswer: Ammonia into a less toxic form The inputs to one cycle of the urea cycle areAnswer: 1 molecule of aspartic acid, 1 molecule of ammonia, 1 molecule of carbon dioxide, 3 molecules of ATP Which of the following is the reduced form of a temporary electron carrier molecule?Answer: FADH₂ Which one of the following is a product of both cyclic and noncyclic photophosphorylation?Answer: ATP Which of the following represents a correct ordering of the events that occur during the respiration of glucose in the absence of O₂?Answer: Glycolysis; fermentation The rate of photorespiration in most plants increases at.higher temperatures. Some plants have evolved a somewhat round-about system to deal with this problem. This series of reactions is calledAnswer: C₄ pathway NADP⁺ is reduced to NADPH duringAnswer: Light dependent reactions More ATP is manufactured during __________ than at any other time in all of cellular metabolism.Answer: Oxidative phosphorylation Electron transport systems play a vital role inAnswer: Light-dependent reactions Antenna complexes, electron transport chains, and carbon fixation are all found inAnswer: Plant cells Where does the O₂ come from that is essential for the proper functioning of oxidative phosphorylation?Answer: Light reactions of photosynthesis Carbon fixation requires the expenditure of ATP molecules which is generated byAnswer: ETS (electron transfer system) during the light reactions A cyclic electron transport process is the characteristic ofAnswer: Photosynthesis