(Question in description) Explain why choice G is the correct answer?

Question

Enzymes are proteins that have a three-dimensional shape that is specific to a particular substrate. Environmental conditions can change the shape of the protein. What is the most likely result if the shape of the enzyme changes?

f. The substrate will change its shape to match the enzyme.

g. The enzyme will no longer be able to catalyze the reaction with the substrate. - correct

h. The products made from the enzyme and the substrate will be changed.

j. The enzyme will be able to bind to more diverse substrates than before.

Answer 1

Imagine an enzyme as a pencil sharpener, and the substrate as a pencil. The shape of the sharpener in both the size of the hole and angle of the blade works perfectly to sharpen the pencil. If you changed the shape of the hole of the pencil sharpener, or the angle of the blades within it, it will no longer be able to sharpen the pencil. Either the pencil will not fit into the sharpener (the substrate does not bind to the enzyme) or the pencil fits but is not sharpened (substrate binds, but the enzyme is unable to catalyze the reaction).

Answer 2

Enzymes and substrates both have specific shapes and they go together like a lock and key. If you change the shape of the key (in this case the enzyme) chances are it will no longer fit into the lock (the substrate). If they no longer fit together, a reaction cannot happen.