this is one explanation of enzyme specificity that states an enzyme and its substrate possess specific complementary geometric shape that fits exactly into one another

Yes, enzymes are specific in nature and is best explained by Lock and key hypothesis.

Explanation:

- Lock and key hypothesis explains the mechanism of enzyme action and was given by Emil Fischer in the year 1984.

- This theory states that both enzyme and substrate molecules have specific geometrical shapes.

- We can correlate this with lock and key, which has special geometrical shapes in the region of their activity.

- Just as a lock can be opened by its specific key, a substrate molecule can be acted upon by a particular enzyme only, and thus enzymes are specific in nature.

- Enzyme posses the active site where substrate molecules bind. These active sites contain groups such as - NH2, - COOH, - SH for interaction with substrate molecules.

- An enzyme-substrate complex is formed, substrate undergo chemical change and form products. The product no longer fits into the active site and thus is liberated in surrounding medium.

Enzymes are usually very specific as to which reactions they catalyze and the substrates that are involved in these reactions. The enzyme and the substrate possess specific complementary geometric shapes that fit exactly into one another. This is often referred to as "the lock and key" model.