life hem intro to macromolecules notes

Monomers and Polymers

  • Monomers are the building blocks of polymers.
  • Dehydration synthesis: A monomer forms a covalent bond to another monomer, releasing a water molecule.
    • Carbohydrates, nucleic acids, and proteins all contain multiple types of monomers.
    • Composition and sequence are important to function.
  • Hydrolysis: A bond is broken by adding a water molecule.
    • One molecule gains "H," and the other gains "OH."
    • Generally releases energy.

Carbohydrates

  • Made of carbon, hydrogen, and oxygen.
  • Monosaccharides: Simple sugars containing 3-7 carbon atoms.
    • Examples: glucose, fructose, galactose
    • Isomers of each other, differing in the organization of their atoms.
  • Disaccharides: Form when two monosaccharides bond via dehydration synthesis.
    • Examples: lactose, maltose, sucrose
  • Polysaccharides: Long chains of monosaccharides linked by glycosidic bonds.
    • The chain may be branched or unbranched.
    • Examples: starch, glycogen, cellulose, chitin
  • Starch: Stored form of sugars in plants.
  • Glycogen: Storage form of glucose in humans.

Protein Structure

  • Primary structure: Sequence of amino acids.
  • Secondary structure: Due to interactions of the peptide backbone.
    • Beta-pleated sheets: Hydrogen bonding.
      • Parallel: Backbones interact, and sequences match.
      • Antiparallel: Opposite sequences, and backbones interact.
    • Alpha helix: Hydrogen bonds between different layers of the helix.
  • Tertiary structure: Due to interactions of side chains.
    • Hydrophobic and hydrophilic regions attract each other.
    • Hydrogen bonds might form.
  • Quaternary structure (more than one polypeptide): Arrangement of multiple chains together.

Triglycerides (Fats)

  • Fatty acids: Carbon chains (hydrophobic) and an acidic carboxyl group.
  • Glycerol can bond with 3 other fatty acids through dehydration, resulting in a triglyceride.
    • Ester bonds.
  • Saturated fat: Saturated by hydrogen.
    • Solid at room temperature.
    • Unhealthy (e.g., butter).
    • Dense.
    • No double bonds.
  • Unsaturated fat: Less hydrogen.
    • Liquid at room temperature.
    • Kinks formed, less dense, healthier (e.g., oils).

Macro Molecule Building Blocks, Functions, and Examples

  • Carbohydrates:
    • Building blocks: Monosaccharides
    • Functions: Quick/short-term energy, source of dietary fiber.
    • Examples: Glucose, sucrose (simple sugar), starch, glycogen.
  • Lipids (Fats, phospholipids):
    • Building blocks: Fatty acids or long-chain glycerol.
    • Functions: Long-term energy, make up biological membranes.
    • Examples: Waxes, oils, grease, steroids
  • Proteins:
    • Building blocks: Amino acids
    • Functions: Provide cell structure, send chemical signals, speed up chemical reactions (enzymes), antibodies.
    • Examples: Keratin, hormones, enzymes, antibodies.
  • Nucleic Acids:
    • Building blocks: Nucleotides
    • Functions: Store and pass on genetic information.
    • Examples: DNA, RNA

Nucleic Acids

  • DNA is found in the nucleus in eukaryotes.
    • Chromosomes: DNA is broken up into long linear pieces.
    • Chromosomes contain tens of thousands of genes.
  • Located in the nucleoid of prokaryotes.
    • Chromosomes are smaller and often ring-shaped.
  • Monomers = Nucleotides:
    • When combined, the resulting chain is called a polynucleotide.
  • Made up of:
    • Nitrogen-containing ring (nitrogenous base).
    • Five-carbon sugar.
    • At least one phosphate group.
  • Purines: Adenine (A) & Guanine (G) - two rings.
  • Pyrimidines: Thymine (T), Uracil (U), & Cytosine (C) - single ring.
  • DNA's sugar: Deoxyribose - 2nd carbon has a hydrogen.
  • RNA's sugar: Ribose - 2nd carbon has a hydroxyl group.
  • Polynucleotide chain has directionality:
    • 5' - phosphate group
    • 3' - hydroxyl of the last nucleotide
  • DNA sequences are written in the 5' to 3' direction.
  • DNA chains are found in a double helix.
    • Two complementary chains are stuck together.
    • Sugar-phosphate backbone.
    • Bases interior - bound to each other by hydrogen bonds.
    • Two strands have opposite directionality - antiparallel orientation.
  • RNA is single-stranded.
    • mRNA: An intermediate between a protein-coding gene & its protein product.
    • rRNA: Helps accelerate chemical reactions; helps mRNA bind to the right spot.
    • tRNA: Brings amino acids to the ribosome.
    • RNA is involved in protein synthesis & gene regulation.