Question

You have just isolated a new enzyme and have determined the velocity of reaction at three different substrate concentrations. You find that the slope of the product versus time curve is the same for all three concentrations. What can you conclude about the conditions in the reaction mixture?

1) The reaction is not affected by substrate concentration
2) The reaction is affected by substrate concentration
3) The reaction is not affected by time
4) The reaction is affected by time

Answer 1

The observation that the velocity of the enzymatic reaction remains the same across different substrate concentrations indicates that the enzyme is saturated and operating at maximum capacity.

Step-by-step explanation:

If the slope of the product versus time curve is the same for all three substrate concentrations, this suggests that the enzyme is operating under saturated conditions. Under these conditions, increasing substrate concentration does not increase the velocity of the enzyme-catalyzed reaction because all the active sites on the enzyme molecules are occupied by substrate molecules. In other words, further increases in substrate concentration will not affect the rate of reaction because the enzyme is already working at its maximum capacity.