Question

how do enzymes catalyze reactions?
enzymes bind with and change the conformation of substrates.
enzymes are consumed by a reaction to catalyze it.
enzymes carry out a reaction without needing reactants.
enzymes change the free energy of the reactants.
enzymes increase the activation energy of a reaction.

Explanation:

Enzymes are biological catalysts. They bind to substrates, inducing a conformational change that lowers the activation - energy of the reaction. They are not consumed in the reaction, require reactants (substrates), and do not change the free - energy of the reactants but rather the activation energy to speed up the reaction.

Answer:

Enzymes bind with and change the conformation of substrates.