BIO152H5 Chapter Notes - Chapter 3: Peptide Bond, Hydrogen Bond, Amine
Document Summary
Act as signals that help coordinate the activities of many cells. Receive chemical signals from outside cell and initiate response. Provide support for cells and tissues; form structures such as hair, feathers, cocoons and spider webs. Move substances across cell membrane and throughout body. Amino acid structure: carbon attached to 1)amino functional group (nh2) 2)carboxyl functional group (cooh) 3)h 4)r-group (differentiates between amino acids) In water, nh2 attracts proton, forms nh3+ and carboxyl group loses proton to form coo-. The charges on these functional groups: help amino acids stay in solution where they can interact with each other and other solutes, add to their chemical reactivity. Nature of side chains: amino acids with non-polar side chains do not have charged or electronegative atoms capable of forming hydrogen bonds with water. Polar side chains are hydrophilic, dissolve in water: influences their chemical reactivity. Structural isomers: same atoms but differ in order in which covalently bonded atoms are attached.
