CHAPTER 2 Protein Section 2 Proteins: Their biological Functions and Primary structure
CHAPTER 2 Protein Section 2 Proteins: Their Biological Functions and Primary Structure
Outline 5.1 Proteins- Linear Polymers of Amino Acids 5.2 Architecture 5.3 Many biological Functions 5.4 May be conjugated with Other Groups 5.6 Purification 5.7 Primary Structure Determination 5.8 Consider the Nature of sequences
Outline 5.1 Proteins - Linear Polymers of Amino Acids 5.2 Architecture 5.3 Many Biological Functions 5.4 May be Conjugated with Other Groups 5.6 Purification 5.7 Primary Structure Determination 5.8 Consider the Nature of Sequences
5. 1 Proteins are Linear polymers ofamino Acids R RI O Ro HN—CH—C t Hgn-CH-c H3N-GH-C一N-GHC O H Amino acid I Amino acid 2 Dipeptide
5.1 Proteins are Linear Polymers of Amino Acids
The Peptide bond n partially positive, A pure double bond between C and O would permit free rotation o partially negative The other extreme would prohibit c-Nbond rotation but would place too great a charge on O and N (c) The true electron density is intermediate. The barrier to C-Nbond rotation of about 88 kI mol is enough to keep the amide group planar
•N partially positive; • O partially negative The Peptide Bond
1125nm R I21.1 12s.2 0.13m 14 1212 1156 118z° R 0.1m is usually found in the trans conformation .has partial ( 40%)double bond character .is about 0.133 nm long-shorter than a typical single bond but longer than a double bond
•is usually found in the trans conformation •has partial (40%) double bond character •is about 0.133 nm long - shorter than a typical single bond but longer than a double bond