2025 Enzyme Engineering 1 Homework 3  Due date: May 27

1. An enzyme-catalyzed reaction was found to be affected by an inhibitor.

The following results were obtained at fixed total enzyme concentration.

Substrate concentration (mmol/l)	Initial reaction velocity (mmol/l․min)
	Uninhibited	With 1 mmol/l inhibitor
2	0.55	0.25
2.5	0.66	0.30
3.3	0.80	0.36
5	1.02	0.47
10	1.43	0.65

1) What is the type of inhibition?

2) What is the degree of inhibition (%)?

3) Calculate time to reach 90% substrate conversion (initial substrate

concentration, S0=100 g/l)

2. Two sets of enzyme reactions were carried out and data were given below (Vo: initial reaction velocity in the absence of inhibitor, VI: initial reaction velocity in the presence of inhibitor). What is the degree of inhibition in each reaction?

S (mM)	Vo (μM/min): No inhibitor	VI (μM/min) by 1 mM inhibior A	VI (μM/min) by 10 mM inhibior B
0	0	0	0
1	21	16	11
2	34	26	20
5	56	43	37
10	70	54	54
100	92	70	88

3. Two sets of enzyme reactions were carried out and data were given below (Vo: initial reaction velocity in the absence of inhibitor, VI: initial reaction velocity in the presence of inhibitor). What is the degree of inhibition in each reaction?