Amino Acids,Peptides,and Proteins Proteins Occur in every living organism Are of many different types Have many different biological functions Keratin of skin and fingernails -Fibroin of silk and spider webs Estimated 50,000 to 70,000 enzymes that catalyze the biological functions of the human body Made up of many amino acids linked together Proteins ▪ Occur in every living organism ▪ Are of many different types ▪ Have many different biological functions ▪ Keratin of skin and fingernails ▪ Fibroin of silk and spider webs ▪ Estimated 50,000 to 70,000 enzymes that catalyze the biological functions of the human body ▪ Made up of many amino acids linked together Amino Acids, Peptides, and Proteins