MC

Macromolecules

Carbohydrates

  • Monomer (Monosaccharide): The building blocks of carbohydrates; simple sugars.

    • Example: Glucose (C₆H₁₂O₆).

  • Disaccharide: Two monosaccharides joined by a glycosidic linkage.

    • Example: Sucrose (glucose + fructose).

  • Polysaccharide: Many monosaccharides linked together.

    • Storage polysaccharides → store energy (e.g., Starch in plants, Glycogen in animals).

    • Structural polysaccharides → provide support (e.g., Cellulose in plant cell walls, Chitin in exoskeletons).

  • Glycosidic linkage: The covalent bond formed between two monosaccharides in a dehydration reaction (–C–O–C–).

🟡 Lipids

  • Triglyceride: A lipid made of 3 fatty acids + 1 glycerol; main form of stored energy.

  • Steroid: Lipid with a four-ring carbon skeleton; includes cholesterol and hormones (e.g., testosterone, estrogen).

  • Glycerol: A 3-carbon alcohol with hydroxyl groups; backbone for triglycerides and phospholipids.

  • Fatty Acid: Long hydrocarbon chain with a carboxyl group at one end.

  • Phospholipid: Lipid made of 2 fatty acids + glycerol + phosphate group; forms cell membranes.

  • Saturated fatty acid: No double bonds; straight chains; solid at room temp (e.g., butter).

  • Unsaturated fatty acid: One or more double bonds; bent chains; liquid at room temp (e.g., olive oil).

  • Ester bond: The covalent bond formed between glycerol’s –OH and a fatty acid’s –COOH during triglyceride formation.

🔵 Proteins

  • Amino acids: Monomers of proteins; contain an amino group (–NH₂), carboxyl group (–COOH), hydrogen, and R-group.

  • Peptide bond: Covalent bond formed between amino acids (between the –NH₂ of one and the –COOH of another) via dehydration.

  • Primary structure: Linear sequence of amino acids in a polypeptide.

  • Secondary structure: Local folding of polypeptide into α-helices or β-pleated sheets stabilized by hydrogen bonds.

  • Tertiary structure: Overall 3D shape of a single polypeptide, stabilized by interactions (hydrogen bonds, ionic bonds, disulfide bridges, hydrophobic interactions).

  • Quaternary structure: Association of multiple polypeptide chains into a functional protein (e.g., hemoglobin).