Biochemistry 2280A Lecture Notes - Lecture 2: Protein Biosynthesis, Histidine, Asymmetric Carbon

• School: Western University
• Department: Biochemistry
• Course: Biochemistry 2280A
• Professor: Bonnie Mac Lachlan

Document Summary

Proteins are one of the major components of cells performing multiple functions as enzymes, pumps and channels, enzymes, hormones and more. They are composed of linear chains arising from amino acids and, depending on their sequence, can assume many structures. The way amino acids are arranged dictates its folding and its functions. Primary structure is linear sequence of amino acids encoded by dna. The amino acids are linked by peptide bonds, which link an amino group and a carboxyl group (this releases water each time a bond is formed). Secondary structure is the folding into a alpha helix or. Alpha helix: h bonds between near by amino acids. Beta sheet: h bonds between near by sheets. Tertiary structure: proteins fold into a compact globular shape with hydrophobic side chains inside sheltered from surrounding water. Quaternary structure: two or more polypeptides chains come together to form a functional molecule (haemoglobin) Central dogma: dna (replicates) rna protein (20 amino acids)