Proteins can perform many different functions in living cells. one major function, acting as a catalyst for chemical reactions, can also be performed by what other kind of organic molecule?

RNA (Ribonucleic acid)

Explanation:

Ribonucleic acid (RNA) is a polymeric molecule which is important in various biological roles such as coding, decoding, regulation and expression of genes.RNA is assembled as a chain of NUCLEOTIDES.

Some RNA molecules play an active role within cells by CATALYZING BIOLOGICAL REACTIONS, controlling gene expression, or sensing and communicating responses to cellular signals. One of these active processes is protein synthesis. Protein synthesis is a universal function in which RNA molecules direct the synthesis of proteins on ribosomes. This process uses transfer RNA molecules to deliver amino acids to the ribosome, where ribosomal RNA then links amino acids together to form coded proteins.

every el niño cycle is different. every year.

"d.) carbon dioxide and hydrogen sulfide"