Lecture on Amino Acids and Their Structure

Introduction

• Focus on amino acid structure
• Importance in biochemistry and human metabolism
• Example used: Hemoglobin

Hemoglobin Overview

• Found in red blood cells
• Responsible for oxygen transport
• Comparison to a car carrying passengers (oxygen)
• Delivers oxygen to tissues, where it's used to generate ATP (energy source)

Role of Amino Acids

• Building blocks of proteins like hemoglobin
• 20 different amino acids
• Combine in various ways to form different proteins

Amino Acid Structure

• Main Components:
  • Amino group
  • Carboxylic acid group
  • Alpha carbon (central carbon)
  • Hydrogen atom
  • Unique side chain (R group)
• Chirality:
  • Alpha carbon is a chiral carbon (has four unique groups)
  • Chirality refers to optical activity (rotates plane-polarized light)
  • Exception: Glycine (R group is a hydrogen atom, no chirality)

Fischer Projections

• L-Amino Acid Configuration:
  • Amino group on the left
  • Only form found in the human body
• D-Amino Acid Configuration:
  • Amino group on the right
  • Not found in human body
• Enantiomers:
  • L and D forms are mirror images but not superimposable
  • Comparison to left and right hands

Summary

• Big picture: Amino acids in metabolic processes
• Structure: Alpha carbon, chirality, exception of glycine
• Importance of L-configuration in the human body