Chemical Components of Cells Part II- Protiens 1.19.16 Proteins are composed of amino acids General structure of an amino acid where R is one of twenty different side chains At pH=7, both the carboxyl and amino groups are polarized In cell, cytosol will always make it ionized Amino acids are linked together by peptide bonds R Groups have different chemical properties: Be able to decide if each R-group is hydrophobic or hydrophilic Proteins are folded polymers of amino acids Primary - linear Secondary - alpha or beta Tertiary - combination of alpha and beta, globular Quaternary - combination of globular structures Folding of protein determines function Most proteins adopt a single highly preferred conformation