6. Enzyme A follows Michaelis-Menten kinetics. a) The KM of enzyme A for its sub

Question

6. Enzyme A follows Michaelis-Menten kinetics.

a) The KM of enzyme A for its substrate S is KMS = 1.0 mM. Enzyme A also acts on substrate T and its KMT = 10.0 mM. Explain which is the preferred substrate, S or T? ________________________________________________________________________________________

b) The rate constant k2 with substrate S is 2.0 x 104 sec-1 and 4.0 x 105 sec-1 for substrate T. Does enzyme A use substrate S or T with greater catalytic efficiency? Explain. _________________________________________________________________________________________ _________________________________________________________________________________________

Explanation / Answer

a) S is the preferred substrate, because it requires low concentration to achieve half of the maximum rate.

Substrate T requires more concentration (KM=10.0mM) to achieve half of the maximum rate.

Hence S is the preferred substrate.

b) If rate of the reaction is high then activation energy is low, that indicates catalyst has greater effinity.

Because catalyst increases the rate of the reaction by decreasing activation energy of the reaction.

substrate T has greater rate constant than substarte S.

So enzyme A use substrate T with greater catalytic efficiency.

Related Questions

Navigate

• Browse (All)
• Browse 6
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.