Question

In the lock-and-key model of enzyme action, the ___________ fits into the __________ of the enzyme.

Answer 1

In the lock-and-key model of enzyme action, the ___ substrate________ fits into the __active site________ of the enzyme.
This model was proposed by the Emil Fischer in 1894 and proposed that enzymes have different shape and proposed lock and key model
so i conclude option C is correct
hope it helps

Answer 2

C) Substrate; active site