Overview
This lecture introduces the basic structure and elements of amino acids, highlighting their general features and the specific example of methionine.
Structure of Amino Acids
- Amino acids are composed of carbon, hydrogen, oxygen, and nitrogen; some also contain sulfur.
- Each amino acid has a central tetrahedral carbon atom (alpha carbon).
- Four groups bond to the central carbon: an amino group, a carboxyl group, a hydrogen atom, and an R group (side chain).
- The R group determines the identity and properties of each amino acid.
Methionine Example
- Methionine is an amino acid whose R group contains sulfur.
- Like all amino acids, methionine's amino and carboxyl groups are on opposite sides of the central carbon.
Key Terms & Definitions
- Amino Acid — Organic compound with an amino group, carboxyl group, hydrogen, and R group attached to a central carbon.
- Tetrahedral Carbon — A carbon atom bonded to four different groups in a three-dimensional shape.
- R Group (Side Chain) — Variable group in amino acids that determines specific characteristics.
- Methionine — An amino acid whose side chain contains sulfur.
Action Items / Next Steps
- Review the structure and labeling of a generic amino acid.
- Prepare to identify and compare different amino acids based on their R groups.