When an enzyme affects a biological reaction,
it is consumed
it is not used up
more enzyme is made
its concentration changes

Enzymes are very effective in fastening up biochemical reactions. They can catalyze up to several million responses per second. As a result to which, the variation in speeds of biochemical reactions with and without enzymes may be immense. A normal biochemical reaction possibly take hours or regular days to happen under typical cellular conditions without an enzyme, but fewer than a

i think its the first one

i think the answer would be d