Review of Macromolecules

Types of Macromolecules

1. Carbohydrates
   • Empirical formula: CH2O
2. Lipids
   • Includes triglycerides, fatty acids, steroids, phospholipids
3. Proteins
4. Nucleic Acids

Carbohydrates

• Monosaccharides: Monomers of carbohydrates

  • Glucose
    • Six-carbon sugar, forms six-membered ring
    • Aldohexose (contains an aldehyde group in straight chain)
  • Fructose
    • Isomer of glucose, forms five-membered ring
    • Ketohexose (contains a ketone group)
  • Galactose
    • Stereoisomer of glucose
    • C4 epimer (differs at carbon 4)
  • Ribose
    • Aldopentose, five-carbon sugar

• Disaccharides

  • Sucrose: Glucose + Fructose
  • Maltose: Two glucose units
  • Lactose: Glucose + Galactose

• Polysaccharides

  • Starch: Energy storage in plants
    • Composed of amylose (straight) and amylopectin (branched)
  • Glycogen: Energy storage in animals
  • Chitin: Structural material in insects
  • Cellulose: Structural function in plant cell walls

Proteins and Amino Acids

• Monomers of Proteins: Amino acids
• Structure of Amino Acid
  • Central carbon with carboxyl group, amino group, hydrogen atom, and R group
• Types of Amino Acids
  • Nonpolar aromatic (e.g., phenylalanine)
• Protein Structure Levels
  • Primary: Amino acid sequence
  • Secondary: Alpha helix and beta-pleated sheets
  • Tertiary: Folding of polypeptide chain
  • Quaternary: Multiple polypeptide chains forming a functional protein

Lipids

• Triglycerides: Long-term energy storage
• Saturated vs Unsaturated Fatty Acids
  • Saturated: No double bonds, solid at room temperature
  • Unsaturated: Double bonds, liquid at room temperature
• Phospholipids: Form cell membranes
  • Composed of glycerol, two fatty acids, phosphate group

Nucleic Acids

• Structure of Nucleotides
  • Composed of phosphate group, ribose sugar, nitrogenous base
• Types of Nucleic Acids
  • DNA: Stores genetic information, double-stranded
  • RNA: Single-stranded, contains uracil instead of thymine

Enzymes

• Characteristics
  • Proteins that speed up chemical reactions
  • Identified by suffix "-ase"

Miscellaneous

• Peptide Bond Formation: Dehydration synthesis
• Macromolecules & Elements
  • Proteins may contain sulfur
  • Nucleic acids contain phosphorus
• False Statements
  • Saturated fatty acids are not liquid at room temperature
  • Lipids do not generally contain phosphorus except for phospholipids