Direction: Enzyme X converts substrates S1 and S2 (which are similar but not
identical) to products P1 and P2 respectively
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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
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- P, Q
- R, S
- Q, S
- Q, R
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).
