What is an enzyme's role in a chemical reaction? ?

What is the answer for the complicated molecules that make up living things usually contain carbon. why is carbon so important in these molecules?

According to theories of how life began, how did early organic molecules begin to separate from the outside world? a: specialized enzymes were required b: chains of amino acids created a barrier c: formation of microspheres or vesicles d: rna catalyzed the formation of membranes

Where is most of the fresh water on earth found a in the ocean b in glaciers and in ice caps c in rivers d in the soil