Which class of molecules is responsible for speeding up chemical reactions?

Enzymes

Explanation:

Id like to add on the Dede12222, another work for Catalyst is Enzymes.

small, big, or no change could occur in the phenotype. it could cause something as simple as a cats ears to curl backwards or something as frighting as death. it could also occur in the protien-coding area and have an effect on that but no effect on the amino acids. what has to occur is a changing in the hox gene or the control gene.

sorry, but you do not have posted the diagram.