Lecture Notes on Biochemistry

Introduction to Biochemistry

Overview of Biochemistry

  • Definition: Biochemistry merges chemical and biological sciences to study living organisms.
  • Scope:
    • Includes the study of biochemical processes and biomolecules.
    • Vital for understanding life sciences.
  • Significance:
    • Provides insights into the origin of life, chemical evolution, and biological evolution.

Nature and Types of Biomolecules

  • Biomolecules: The essential components of life and categorized as:
    • Micro-molecules ( < 1000 Daltons)
    • Macro-molecules ( > 1000 Daltons)

Extraction and Classification of Biomolecules

  • Extraction Process:
    • Cells are ground with mortar and pestle in trichloroacetic acid.
  • Filtering mechanism:
    • Acid-soluble filtrate contains micro-molecules.
    • Residue on filter paper represents macro-molecules.

Micro-molecules

  • Categories:
    • Organic Micro-molecules:
    • Examples: Amino acids, monosaccharides, disaccharides, enzymes.
    • Inorganic Micro-molecules:
    • Examples: Water, minerals, vitamins.

Macro-molecules

  • Categories:
    • Proteins:
    • Fundamental to cell structure and functions.
    • Composed of amino acids linked by peptide bonds.
    • Functions include: structural support (e.g. collagen), enzymes, hormones, and immunoglobulins.
    • Carbohydrates:
    • Most abundant biomolecules.
    • Composed of monomeric units linked by glycosidic bonds.
    • Functions: Energy source (ATP production), structural elements, protective barriers (e.g. bacterial cell walls), and energy storage (glycogen).
    • Lipids:
    • Water-insoluble biomolecules; act as energy reservoirs (triacylglycerol).
    • Key components of cell membranes (phospholipids, cholesterol).
    • Functions include: protection of organs, insulation, and giving smooth appearance to the body.
    • Nucleic Acids:
    • Composed of nucleotides.
    • Types: DNA and RNA.
    • DNA:
      • Carries genetic information; crucial for heredity.
      • Maintains species identity for millions of years.
    • RNA:
      • Plays a significant role in protein synthesis.

Course Learning Objectives

  • Understand fundamental concepts of biochemistry and its relevance to life sciences.
  • Gain knowledge on the origin and evolution of life, types of biomolecules, and the classifications of living organisms.
  • Prepare for future academic applications and research methodologies in biochemistry.

References for Further Reading

  • Lehninger Principles Of Biochemistry by David L. Nelson and Michael M. Cox.
  • Modern Concepts in Biochemistry by R.C. Bohinski.
  • Lippincott Illustrated Reviews: Biochemistry.