Introduction to Biochemistry

Definition

• Biochemistry (Biological Chemistry): Study of chemical processes within and relating to living organisms.
• Concerned with chemical constituents of living cells and their reactions/processes.
• Applies to humans, animals, and plants.

Key Concepts

• Metabolism: Chemical processes for maintaining life (absorption, breakdown of sugars/proteins).
• Principal Biomolecules: Proteins, carbohydrates, lipids, nucleic acids.

Historical Milestones in Biochemistry

• Louis Pasteur: Fermentation is carried out by microorganisms (bacteria/yeast).
• Hans and Edward Buchner: Fermentation can occur in free cell extracts (without living cells).
• Wöhler (1828): Synthesized urea from inorganic compounds.
• Schleiden and Schwann: Cell theory.
• Gregor Mendel: Principles of segregation and independent assortment of genes.
• Friedrich Miescher: Discovered DNA.
• Buchner: Discovered alcoholic fermentation in cell-free extracts.
• Newberg: First used the term biochemistry and proposed biochemical pathways for fermentation.
• Michaelis and Menten: Developed the kinetic theory of enzyme action.

Importance of Biochemistry

• Study of chemical reactions at the molecular level of organisms.
• Helps understand living organisms' extraordinary properties in chemical terms.
• Biochemical markers indicate abnormalities (lipid profile tests, genetic diseases via PCR, protein abnormalities like sickle cell anemia, diabetes via blood sugar testing).

Applications in Daily Life

• Physicians, nutritionists, pharmaceutical industry, and clinical biochemistry.
• Biochemical tests in laboratories detect human abnormalities and test microorganisms.

Overview of Biomolecules

Carbohydrates

• Function: Primary energy source.
• Elements: Carbon, hydrogen, oxygen (ratio: 1:2:1).
• Monomer: Monosaccharides (e.g., glucose).
• Polymer: Polysaccharides (e.g., starch, glycogen, cellulose, chitin).
• Food Sources: Sugar, bread, pasta, fruits, vegetables.

Lipids (Fats)

• Function: Energy storage, insulation, cell membrane structure.
• Elements: Carbon, hydrogen, oxygen.
• Monomer: Glycerol + fatty acids.
• Polymer: Phospholipids, triglycerides.
• Types: Saturated (single bonds, solid at room temp, animal fats), Unsaturated (double/triple bonds, liquid at room temp, plant-based fats).
• Properties: Hydrophobic (insoluble in water), e.g., oils, nuts, waxes.

Proteins

• Function: Transport molecules, speed up reactions, growth, and repair.
• Elements: Carbon, hydrogen, oxygen, nitrogen.
• Monomer: Amino acids (20 types).
• Polymer: Proteins.
• Food Sources: Fish, eggs, meat.
• Examples: Enzymes, antibodies.

Nucleic Acids

• Function: Genetic information, protein synthesis instructions.
• Elements: Carbon, hydrogen, oxygen, nitrogen, phosphate.
• Monomer: Nucleotides (sugar, phosphate group, nitrogen base).
• Polymer: DNA (genetic code, hereditary material), RNA (protein synthesis recipe), ATP (energy carrier).

Summary

• Biochemistry is essential for understanding living organisms and diagnosing diseases.
• Biomolecules play crucial roles in daily life and health, providing energy, building structures, and storing genetic information.

End of Lecture