Biochemistry Lecture Notes

Introduction to Biochemistry

• Definition: Study of chemical processes in living organisms
• Involves chemical constituents of living cells and their reactions
• Includes all living organisms: plants, animals, etc.

Key Concepts in Biochemistry

Chemical Processes in the Body

• Metabolism
• Absorption
• Breakdown of sugars and proteins

Principal Classes of Biomolecules

1. Proteins
2. Carbohydrates
3. Lipids
4. Nucleic Acids

Historical Background

• Louis Pasteur: Fermentation by microorganisms (yeast, bacteria)
• Hans and Edward Buchner (1899): Fermentation can occur in free cell extracts
• Wöhler: Synthesized urea from inorganic compounds (1828)
• Mendel: Principles of segregation and independent assortment of genes
• Miescher: Discovered DNA
• Newberg: Coined the term 'biochemistry' and proposed biochemical pathway for fermentation
• Michaelis and Menten: Developed kinetic theory of enzyme action

Importance of Biochemistry

• Biomolecules serve as indicators of abnormalities in the body
• Example: Lipids used in lipid profile tests to diagnose atherosclerosis
• Proteins related to hemoglobin abnormalities (e.g., sickle cell anemia)
• Carbohydrates used to detect diabetes mellitus

Applications in Daily Life

• Physicians encounter biochemistry daily in diagnosing diseases
• Nutritionists use biochemistry to evaluate dietary needs
• Pharmaceutical industry applies biochemistry to develop medications

Overview of Biomolecules

1. Carbohydrates

• Most common organic molecule; primary energy source
• Elements: Carbon, hydrogen, oxygen (1:2:1 ratio)
• Monomer: Monosaccharides (e.g., glucose, fructose)
• Polymers: Polysaccharides (e.g., starch, glycogen, cellulose)
• Found in: Bread, pasta, fruits, vegetables

2. Lipids

• Function: Energy storage, insulation, cell membrane structure
• Elements: Carbon, hydrogen, oxygen
• Monomer: Glycerol and fatty acids
• Polymers: Phospholipids, triglycerides
• Types: Saturated (solid at room temp) vs. Unsaturated (liquid at room temp)
• Hydrophobic in nature; do not dissolve in water

3. Proteins

• Functions: Transport, speed of chemical reactions, growth, repair
• Elements: Carbon, hydrogen, oxygen, nitrogen
• Monomer: Amino acids (20 types)
• Examples: Enzymes, antibodies
• Found in: Fish, eggs, meat

4. Nucleic Acids

• Functions: Genetic information storage, protein synthesis instructions
• Elements: Carbon, hydrogen, oxygen, nitrogen, phosphate
• Building Blocks: Nucleotides (sugar, phosphate group, nitrogen base)
• Types: DNA (genetic code) and RNA (protein synthesis recipe)
• ATP: Primary energy carrier in cells

Conclusion

• Biochemistry is integral to understanding living organisms and their functions.
• Explains how biomolecules interact and impact health and disease.