Enzyme Science Miscellaneous

Enzyme Science Miscellaneous

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Enzyme Science

Enzyme Science Miscellaneous

Direction: Enzyme X converts substrates S1 and S2 (which are similar but not
identical) to products P1 and P2 respectively

  1. Km values of enzyme X for substrate S1 and S2 are 0.1 mM and 0.01 mM, respectively This suggest that
    P. enzyme X has more affinity towards S1
    Q. enzyme X has low affinity towards S1
    R. enzyme X has more affinity towards S2
    S. enzyme X has low affinity towards S2








  1. View Hint View Answer Discuss in Forum

    The Michaelis constant (Km) is a means of characterizing an enzyme's affinity for a substrate. The Km in an enzymatic reaction is the substrate concentration at which the reaction rate is half its maximum speed. Thus, a low Km value means that the enzyme has a high affinity for the substrate (as a "little" substrate is enough to run the reaction at half its max speed).

    Correct Option: D

    The Michaelis constant (Km) is a means of characterizing an enzyme's affinity for a substrate. The Km in an enzymatic reaction is the substrate concentration at which the reaction rate is half its maximum speed. Thus, a low Km value means that the enzyme has a high affinity for the substrate (as a "little" substrate is enough to run the reaction at half its max speed).

  1. Determine the correctness or otherwise of the following Assertion [a] and Reason [r]
    Assertion : Enzymatic method of tissue dispersion is milder than chemical and mechanical methods.
    Reason : Enzymes work at optimal temperature and pH








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    A : Enzymatic method is mild. Chemical and mechanical methods may tend to destroy the tissue.
    R : Enzymes show their catalytic activity at a particular optimum p H and temperature.

    Correct Option: B

    A : Enzymatic method is mild. Chemical and mechanical methods may tend to destroy the tissue.
    R : Enzymes show their catalytic activity at a particular optimum p H and temperature.

Direction: A double reciprocal plot was created from the specific growth rate and limiting-substrate concentration data obtained from a chemostat experiment. A linear regression gave values of 1.25 hr and 100 mg-hr-l–1 for the intercept and slope, respectively.

  1. The same culture (with the µm and Ks values as computed above) is cultivated in a 10-litre chemostat being operated with a 50 ml/min sterile feed containing 50 g/l of substrate. Assuming an overall yield coefficient of 0.3 g-DCW/g-substrate, the respective values of the outlet biomass and substrate concentration are








  1. View Hint View Answer Discuss in Forum

    NA

    Correct Option: A

    NA

  1. The respective values of the Monod kinetic constants µm (hr–1) and Ks (mg/l) are as follows:








  1. View Hint View Answer Discuss in Forum

    NA

    Correct Option: C

    NA

Direction: A Nick Translation reaction in a final volume of 100µl was carried out by using 25 µCi of labeled [α-32P]–dCTP for labeling a 1.2 Kb λ-Interferon DNA fragment.

  1. If 2.94 × 104 cpm of TCA precipitable counts of the 10 µl sample were taken from 1/10 dilutioa of the 100µl Nick Translation reaction containing 1 µg of γ-Interferon DNA, what is the specific activity of the labeled product?








  1. View Hint View Answer Discuss in Forum

    2.94 × 105 cpm is from 0.1 dilution of 10 µl sample. Thus, 10 µl sample will have 2.94 × 106 cpm but, this 10 µl sample is taken from 100 µl which contain 1 µg of λ-interferon. So, 100 µl of 1 µg interferon sample will have 2.94 × 107 cmp/µg.

    Correct Option: D

    2.94 × 105 cpm is from 0.1 dilution of 10 µl sample. Thus, 10 µl sample will have 2.94 × 106 cpm but, this 10 µl sample is taken from 100 µl which contain 1 µg of λ-interferon. So, 100 µl of 1 µg interferon sample will have 2.94 × 107 cmp/µg.