Question

In an enzyme-catalysed reaction, if [s] = 10 km the velocity of the reaction is about:

Answer 1

since v is 80% of Vmax assume Vmax=1, therefore v=0.80

1/v = Km/Vmax x 1/[S] + 1/Vmax 
1/0.80 = Km/1 x 1/[S] + 1/1 
1/0.80 - 1/1 = Km/[S] * Km/1 was multiplied with 1/[S] 
0.25= Km/[S] but we want [S]/Km ratio so..... 
0.25[S]= Km *remember Km has invisible 1 coefficient 
[S]/Km= 1/0.25 
[S]/Km= 4

 

Answer 2

Answer: The answer is 0.9 vmax

Explanation:

As we know that,

v = vmax × [S] ÷ Km + [S]

So, we have [S]= 10Km Putting the value,

v= vmax × 10Km ÷ Km + 10Km

= vmax 10Km ÷ 11Km

v = 0.9 vmax