Macromolecules include carbohydrates, lipids, proteins & nucleic acids

Carbohydrates: organic compounds made up of carbon, hydrogen, & oxygen

• Types:

  • Monosaccharides: single sugar molecules

    • Glucose, fructose

  • Disaccharides: 2 monosaccharides

    • Sucrose, lactose

  • Polysaccharides: chains of monosaccharides

    • Starch, cellulose

• Structure: typically in a ring form for sugars; backbone of carbon atoms w/ attached functional groups

• Functions:

  • Energy source (glucose)

  • Structural roles (cellulose in plants)

  • Energy storage (glycogen in animals)

• Examples:

  • Starch: energy storage in plants

  • Cellulose: structural component in plant cell walls

Lipids: hydrophobic or amphipathic moleculues insoluble in water but soluble in organic solvents

• Types:

  • Fats & oils: typically triglycerides

  • Phospholipids: form cell membranes

  • Steroids: include cholesterol & hormones

• Structure: composed of glycerol w/ 3 fatty acid chains (triglycerides) or 2 fatty acid chains & a phosphate group (phospholipids)

• Functions:

  • Long term energy storage

  • Important components of cell membranes

  • Serve as signaling molecules

• Examples:

  • Cholesterol: big part of cell membranes —> precursor for steroid hormones

  • Phospholipids: form the bilayer of cell membranes

Proteins: large complex molecules made up of amino acids linked by peptide bonds

• Types:

  • Enzymes: catalyze biochemical reactions

  • Structural proteins: provide support

    • Keratin, collagen

  • Transport proteins: carry substances

    • Hemoglobin

• Structure:

  1. Sequence of amino acids

  2. Folding into alpha-helices or beta-pleated sheets

  3. Full 3D shape of a single polypeptide

  4. Combining multiple polypeptides

• Functions:

  • Serve as enzymes, hormones, structural components

  • Involved in immune response & transport

• Examples:

  • Hemoglobin: transports oxygen in the blood

  • Keratin: provides structural support in hair and nails

Nucleic Acids: biomolecules essential for storing & transporting genetic info

• Types:

  • DNA: stores genetic information

  • RNA: involved in protein synthesis & gene expression

• Structure:

  • DNA: double helix made up of nucleotides w/ sugar-phosphate backbone

  • RNA: single-stranded, contains ribose sugar

• Functions:

  • DNA: genetic blueprint for life

  • RNA: crucial in translating DNA into proteins & other cellular functions

• Examples:

  • DNA: contains instructions for development

  • mRNA: transfers genetic information for protein synthesis