Chemistry 451
Lecture #5:
Amino Acids
Read:
Review (remember):
- D
G = D H - TD S (D G < 0 means reaction is spontaneous)
- H2O: Hydrophobic, Hydrophilic (pg. 23-28; Know that biochemical reactions occur in aqueous solutions)
- Buffers (pg. 34)
HW (Due Wednesday at end of class)
- pg. 92 (problems: 1,2,5a,5c,6a,6c,8)
- optional: pg. 92 (study exercises 1,2,3 and problems 10,11,12)
Objectives:
- Develop a mental image of a protein (3-D polymers of amino acids)
- Know names, three-letter abbreviations and structures for the 20 standard amino acids. (especially histadine, cysteine, phenylalanine, glutamine, glutamate and lysine).
- Identify amino acids as nonpolar, polar/uncharged or polar/charged.
- Be able to draw a peptide given names and sequence of amino acids.
- Draw a zwitterion.
- Draw a titration curve for any amino acid given its pK's, calculate pI where pI = ½(pKi + pKj); (pg. 84).
- Calculate [A-] and [AH] given pK and pH.
- Draw configuration of L and D amino acids (note: L¹
levorotary).
- Know that proteins are the workhorses of biochemistry. Protein form equals function. Amino acid structure determines protein structure and therefore function.