Lecture Notes: Protein Structure and Amino Acids
Introduction
- Discussion about proteins and their components.
- Mention of amino acids as the building blocks of proteins.
Elements in Proteins
- Proteins consist of:
- Hydrogen
- Oxygen
- Nitrogen
- Sulfur
- Phosphorus
Amino Acids
- Monomers of proteins are amino acids.
- There are 20 types of amino acids.
- Essential Amino Acids: Cannot be synthesized by the body, must be obtained from food.
- Non-essential Amino Acids: Can be synthesized by the body.
- Importance of memorizing the 20 amino acids.
Peptide Bonds
- Peptide bonds link amino acids together.
- Formation of peptide bonds is fundamental to protein structure.
Protein Structures
- Proteins have four levels of structure:
1. Primary Structure
- Linear sequence of amino acids.
- Example with four amino acids: Alanine, Glycine, Lysine, Methionine.
2. Secondary Structure
- Formed by polypeptide chains folding into alpha-helix or beta-sheet structures.
- Stability through hydrogen bonds.
3. Tertiary Structure
- Further folding into a 3D shape due to interactions between R groups.
- Example: Enzymes.
4. Quaternary Structure
- Involves two or more polypeptide chains.
- Example: Hemoglobin.
Tests for Proteins
- Biuret Test: Detects protein presence by turning purple in the presence of proteins (e.g., albumin).
- Millon's Test: Another test to confirm proteins, results in purple solution.
Examples
- Primary: Insulin in diabetic medication.
- Secondary: Silk (from silk moths) and keratin (in hair and nails).
- Tertiary: Enzymes and silk.
- Quaternary: Hemoglobin.
Conclusion
- Summary of protein structures and tests.
- Encourage students to review and memorize key concepts.
Notes
- The lecture mentions copying time as part of the learning process.
- Video continuation noted for next session.
These notes provide an overview of key concepts in protein biology, focusing on structure, function, and testing. Ensure to review and familiarize with amino acids and structures for a comprehensive understanding.