Living tissues contain inorganic (water, minerals) and organic (carbon-containing) compounds. Cellular pool has two fractions: acid-soluble (micromolecules) and acid-insoluble (macromolecules).
Heteropolymers made of amino acids linked by peptide bonds. There are 20 types of amino acids (essential and non-essential).
Primary: Linear sequence of amino acids.
Secondary: Alpha-helix or Beta-pleated sheet (due to H-bonds).
Tertiary: 3D folding (essential for biological activity of enzymes).
Quaternary: Assembly of more than one polypeptide (e.g., Hemoglobin).
Carbohydrates: Monosaccharides (Glucose, Ribose), Disaccharides (Sucrose), Polysaccharides (Starch, Glycogen, Cellulose). Linked by glycosidic bonds.
Lipids: Not strictly macromolecules. Water-insoluble. Includes fatty acids, glycerol, triglycerides, and phospholipids (cell membrane).
Polymers of nucleotides (DNA and RNA). Linked by phosphodiester bonds.
A nucleotide = Nitrogenous Base + Pentose Sugar + Phosphate group.
Watson-Crick Model of DNA: Double helix, anti-parallel strands, complementary base pairing (A=T, G≡C).
Biocatalysts (mostly proteins) that speed up metabolic reactions by lowering the activation energy.
Temperature, pH, Substrate concentration, and presence of inhibitors (Competitive vs Non-competitive).