Pepsin, trypsin and chymotrypsin are substances that affect reaction rates, those can be defined as

Enzymes

Explanation:

Enzymes are those proteins which participate in a chemical reaction without being consumed in the reaction. These enzymes work as a catalyst which speed up the rate of the chemical reaction. The enzyme is responsible for converting the substrate into a product. Pepsin is an enzyme present in the stomach it is activated by hydrochloric acid it is a peptic enzyme which converts proteins into peptones, trypsin and chymotrypsin are the enzymes secreted by the pancreas and it is responsible for digestion of proteins.

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds