Describe the levels of protein folding- primary, secondary, tertiary & quaternary structure of proteins. simplified pls

The

different levels of protein structure are known as primary, secondary, tertiary, and quaternary structure. The primary structure is the sequence of amino acids that make up a polypeptide chain. ... The exact order of the amino acids in a specific protein is the primary sequence for that protein.

b. the carbon cycle ensures living things have a source of hydrogen