BCH 261 Lecture Notes - Lecture 7: Lactose Permease, Enolase, Zwitterion
30 Nov 2020
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Document Summary
Hemoglobin (transports o2 in the blood) lactose permease (transports lactose across the cell membrane) Proteins are heteropolymers of 20 common amino acids. Amino acids have properties that are well suited to carry out a variety of biological functions: capacity to polymerize; useful acid-base properties; A nonionized amino acid showing the carboxylic acid group, the -amino group, the hydrogen bonded to the -carbon, and the side chain (r group) that gives the amino acid its unique properties. Zwitterion: amino acid at neutral charge, where the -carboxylic acid group is deprotonated and the -amino group is protonated. The negative charge on the -carboxylate is delocalized over the two oxygen atoms. Alpha-carbon has 4 substituents & is tetrahedral. All alpha a. a (except glycine) have l & d enantiomers. The difference is that they rotate polarized light differently. Chemical formula same, chemical structure slightly diff.
