1) which substance can enter a cell by diffusion without having to be digested? *.

where in your body is there an enzyme that does function at a high or low ph? what is the name of that enzyme and its function?

it marks things for degradation via the proteasome. it alters there celluar location.

in a chemical reaction, the atoms and molecules produced by the reaction are called products. no new atoms are created, and no atoms are destroyed. in a chemical reaction, reactants contact each other, bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to make the products.