🧬 Biochemistry Solved MCQs with Answers

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

1490 solved MCQs

Which of the following is not an essential amino acid?Answer: All of these Which of the following is not a sensible grouping of amino acids based on their polarity properties?Answer: Asp, Ile, and Pro Proteins and macromolecular structures take on their higher order structuresAnswer: All of these What is the product of the catabolic breakdown of Alanine?Answer: Pyruvate How many different amino acids are there?Answer: 20 Amino acids required in the human diet and not synthesized by the body are calledAnswer: Essential Which of the following amino acid contain an imidazolium moiety?Answer: Histidine The sequence of letters 'WYQN' will representAnswer: Tryptophan, tyrosine, glutamine, asparagine The sulphur containing side chain of cysteine isAnswer: Hydrophobic, highly reactive and capable of reacting with another cysteine Which of the following is a nonprotein amino acid?Answer: Dopamine Serine and threonine are polar amino acids due toAnswer: Reactive hydroxyl group in the side chain Which of the following is not the hydrophobic and aromatic amino acid?Answer: None of these Stereo chemical configuration of all a-amino acids derived from proteins isAnswer: L The α-amino acids have a carboxyl group with a pK around __________ , and an amino group with a pK near __________ .Answer: 2.2, and 9.4 Coomassie Blue stains the proteins by reacting withAnswer: Arginine residues Which amino acid when exposed to ninhydrin produces a brown color?Answer: Asparagine Hydrogen bonds in a-helices areAnswer: Roughly parallel to the helix axis The peptide bond in proteins isAnswer: Usually trans unless proline is the next amino acid The molecular formula for glycine is C₂H₅O₂N. What would be the molecular formula for a linear oligomer made by linking ten glycine molecules together by condensation synthesis?Answer: C₂₀H₃₂O₁₁N₁₀ Which of the following is an example of tertiary structure in a protein?Answer: A globular domain The peptide, Val-Lys-Glu-Met-Ser-Trp-Arg-Ala, was digested with cyanogen bromide (CNBr) to produce:Answer: Val-Lys-Glu-Met + Ser-Trp-Arg-Ala In deoxy hemoglobin (Hb), the Fe (II) is coordinated toAnswer: Four nitrogens of heme, the proximal His, and a water molecule In the β-pleated sheetAnswer: All of these The Ramachandran Plot illustrates the fact thatAnswer: The F & Y angles can assume approximately three different values The resonance structures that can be drawn for the peptide bond indicate that the peptide bondAnswer: Both (a) and (b) The major element of secondary structure in myoglobin and hemoglobin isAnswer: The a-helix An oil drop with a polar coat is a metaphor referring to the three dimensional structure ofAnswer: Globular proteins What was the first protein whose complete tertiary structure was determined?Answer: Myoglobin The peptide bond in proteins isAnswer: Planar, and usually found in a trans conformation In β-pleated sheet structures neighbouringAnswer: Neighboring chains are hydrogen bonded