Mcat Amino Acids Study Guide Rated A+

If an amino group doesn't have a pKa for its side chain (such as glycine), how do you find pI? {Ans: pI = (pKa1 + pKa2) / 2 Take the avg of the pKa values pI(glycine) = (2.3 + 9.6)/2 round > (2+10)/2 = 6}Chiral amino acids can be classified as _ or _ when looking at them in a 3D structure, or _ or _ when looking at them in a biological standard format {Ans: R or S D or L R/S do not directly relate to D/L. A D amino acid may be R or S.}A chiral carbon must be _hybridized, _ with a bond angle of _ and attached to _ {Ans: sp3 tetrahedral 109.5° 4 unique substituents}If the N in asparagine is replaced by an O via transamination, we get _. If we remove the second N in the backbone, we get _ {Ans: aspartate (an acidic aa) oxaloacetate (OAA) - an intermediate in the TCA cycle}Valine (Val, V) Non-polar, hydrophobic {Ans: }due to its ring, it introduces a 'kink' into polypeptide chains - forces groups toward each other and away from the ring in its R group {Ans: proline