🧬 Biochemistry Solved MCQs with Answers

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

1490 solved MCQs

Headspace analysis is carried out in order toAnswer: Analyse volatile compounds from solid or liquid samples Split injection is carried out byAnswer: Splitting off some of the sample so that it does not enter the column What does the retention factor, k', describe?Answer: The migration rate of an analyte through a column Theoretical plates are used toAnswer: Estimate the efficiency of a column What does the selectivity factor describe?Answer: The relative separation achieved between two species Helium is generally preferred as carrier gas over nitrogen and hydrogen becauseAnswer: All of the above The column is heated toAnswer: All of the above What are the benefits of decreasing the column internal diameter?Answer: Increased resolution Sample retention in the column is measured byAnswer: All of the above Column bleeding occurs whenAnswer: Traces of the stationary phase are eluted Which of the following are not used as stationary phases in a GC column?Answer: Silica Doubling the column's length increases resolution by a factor ofAnswer: (2)⁰⋅⁵ Sample injection is considered successful ifAnswer: The sample is concentrated at the start of the column Which of the following gases is unsuitable for use as a GC carrier gas?Answer: Oxygen Thin layer chromatography isAnswer: Adsorption chromatography In gas chromatography, the basis for separation of the components of the volatile material is the difference inAnswer: Partition coefficients In reverse phase chromatography, the stationary phase is madeAnswer: Non-polar Ion exchange chromatography is based on theAnswer: Electrostatic attraction A combination of paper chromatography and electrophoresis involvesAnswer: Both (a) and (b) Which of the following is the basis of first dimension of separation for two-dimensional electrophoresis?Answer: Isoelectric point What is meant by rotating frame of reference?Answer: If the laboratory itself is imagined to be rotated at the Larmor frequency, viewing that individual magnetic moment vectors are fixed in space The sequence of amino acids in proteins can be determined by means ofAnswer: All of the above Why is it advantageous to record many FID signals from the same sample and then add them together?Answer: To increase sensitivity In FT-NMR, how are nuclei excited?Answer: By radio-frequency radiation whose frequency is swept across a predetermined range What is the name given to the relaxation process due to an interaction between an excited nucleus and the magnetic fields caused by nuclei in molecules moving around in the sample?Answer: Spin - lattice relaxation Cytochrome C has an isoelectric pH ofAnswer: 10.05 What does the Michelson interferometer do?Answer: Modulate the I.R. signal at a lower frequency, so that it can be observed by a detector In scanning electron microscopyAnswer: A specimen is fixed and then coated with thin layer of a heavy metal The frequency of precession, the transition frequency and the Larmor frequency areAnswer: Different terms for the same frequency How do you turn a signal recorded in the time domain into a frequency domain signal?Answer: Fourier transformation