Isomers and Pharmacology Quiz

Chemistry of Macromolecules

• Isomers: Molecules with the same molecular formula but different arrangements of atoms.
  • Structural isomers: Different arrangements of atoms.
  • Geometric isomers: Different angles/orientations due to single or double bonds.
  • Enantiomers: Mirror images of one another, but chemically identical in pairs.
• Particularly useful: Parkinson's disease (PD) treatment.
• L-dopa: A chemical precursor to dopamine synthesis in the brain.
• Dopamine: Neurotransmitter controlling functions, including movement.

Essential Elements

• Carbon (C)
• Hydrogen (H)
• Oxygen (O)
• Nitrogen (N)
• Phosphorus (P)
• Sulfur (S)

Bonds

• Intramolecular bonds (within molecules):
  • Ionic bonds: Metal + nonmetal with unequal electron sharing, forming charged atoms.
  • Covalent bonds: Two or more nonmetals sharing electrons.
• Polar bonds: Covalent bonds with a polarity difference between the bonded atoms.
• Hydrogen bonds: Electrostatic forces between molecules, holding water molecules, DNA bases, and proteins.

Properties of Water

• Polar Covalent: Hydrogen sharing electrons unequally with oxygen.
• Universal Solvent: Dissolves many substances, unlike lipids.
• High Heat Capacity: Stores lots of heat energy.
• High Heat of Vaporization: Requires a lot of energy to boil water.
• High Cohesion/Adhesion: Water molecules stick together, creating surface tension.
• Less Dense as a Solid: Ice is less dense than liquid water.

pH

• Acidic: <7, high H+.
• Neutral: 7, equal H+ and OH-.
• Basic: >7, high OH-.
• pH Scale: Measures acidity or basicity of a solution.

Carbohydrates

• Monosaccharides: Simple sugars, the monomers for carbohydrates.
• Disaccharides: Two monosaccharides joined together.
• Polysaccharides: Many monosaccharides joined together; include starch, cellulose, and glycogen.
• Types of polysaccharides contain different types of ester bonds, and may differ in structure (e.g. branched vs. unbranched).

Lipids

• Composed of C and H atoms.
• Nonpolar and hydrophobic; tails of hydrocarbons are hydrophobic.
• Component tails are important for structure as well as energy storage.

Proteins

• Monomer: Amino acids (20 different types).
• Structure levels:
  • Primary: Sequence of amino acids.
  • Secondary: Alpha helix and beta sheets.
  • Tertiary: 3D structure of a single polypeptide chain.
  • Quaternary: Multiple polypeptide chains associate.
• Enzymes: Proteins that catalyze reactions.
  • Reduce activation energies: Accelerate chemical reactions in biological systems.

Nucleic Acids

• Monomer: Nucleotides (contain C, H, O, N, and P).
• DNA: Double-stranded, comprised of two strands arranged anti-parallel (5' → 3' and 3' → 5').
• RNA: Single-stranded, plays a crucial role in protein synthesis (transfer RNA [tRNA], messenger RNA [mRNA] and ribosomal RNA [rRNA]).

Cell and Organelles

• Eukaryotic cells: Contain membrane-bound organelles.
• Prokaryotic cells: Lack membrane-bound organelles.
• Organelles' functions: Each organelle has a distinct function, e.g., ribosomes synthesize proteins and mitochondria produce energy.
• Cells and biological organization: Cells are the basic units of life, and they combine to form tissues, organs, and organ systems.
• Cell Motility: Mechanisms by which cells move (e.g. cilia, flagella).

Semipermeable Membranes

• Semipermeable membranes: Membranes that control what enters and leaves a cell.
• Passive transport: Molecules moving across a membrane from high to low concentration (e.g., osmosis).
• Active transport: Molecules moving from low to high concentration (requiring energy).
• Electro-chemical gradient: Determines the net passive transport rate of charged particles.

Intracellular Signaling and Gene Expression

• Gated channels: Ion channels affected by voltage, ligands, or physical tension.
• Active transport: Moving molecules against the concentration gradient (e.g., Protein pumps.)
• Cotransporters: Using the energy release from a moving substance to move another substance against its concentration gradient.
• Bulk transport (endo & exocytosis): Vesicle packaging, transport and release to move molecules across a membrane.

DNA Replication

• Semiconservative replication: Each new DNA molecule has one original strand and one new strand.
• DNA Polymerases: Enzymes that synthesize DNA strands from nucleotides.
• Helicase: Enzyme that unwinds DNA during replication.
• Replication fork: Point where strands separate to create a bubble.
• Lagging and Leading strand: The leading strand is copied continuously where as the lagging strand is copied in small sections [okazaki fragments].

Transcription

• Eukaryotic vs. Prokaryotic: Regulation and location differ.
• Transcription factors: Proteins that bind to DNA and regulate gene expression.
• Promoter regions: On DNA, specify where replication begins.
• Repressor regions: On DNA, specify where the process stops.
• Operons: In prokaryotes, a cluster of genes regulated by a common promoter region.