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Chapter 2 & 3 Chemistry & Biology Review - Vocabulary Flashcards

Chapter 2: Chemistry

  • Composition of matter
    • Elements: cannot be broken down by ordinary chemical means; periodic table lists elements.
    • Atoms: unique building blocks for each element; composed of protons (+), neutrons (neutral), and electrons (-).
    • Ions: charged atoms
    • Cations: elements with a positive charge due to giving up an electron
    • Anions: elements with a negative charge due to receiving an electron
  • Elements of the Human Body
    • Major elements (~96% of body mass):
    • Oxygen (O)
    • Carbon (C)
    • Hydrogen (H)
    • Nitrogen (N)
    • Lesser elements (~3.9% of body mass):
    • Calcium (Ca), phosphorus (P), potassium (K), sulfur (S), sodium (Na), chlorine (Cl), magnesium (Mg), iodine (I), iron (Fe)
    • Trace elements (< 0.01% of body mass):
    • Examples include chromium (Cr), manganese (Mn), zinc (Zn)
  • Chemical Reactions
    • Occur when chemical bonds are formed, rearranged, or broken.
    • Represented as chemical equations: A + B \rightarrow AB
    • Chemical equations contain:
    • Molecular formula for each reactant and product
    • Relative amounts of reactants and products, which should balance
    • Patterns of chemical reactions:
    • Synthesis (combination) reactions — forming bonds; anabolic
    • Decomposition reactions — breaking bonds; catabolic
    • Exchange (displacement) reactions — bonds made & broken
  • Class of Compounds
    • Inorganic compounds: water, salts, many acids and bases; do not contain carbon
    • Organic compounds: carbohydrates, fats, proteins, nucleic acids; contain carbon (usually large)
  • Inorganic Compounds
    • Water: 60%–80% of the volume of living cells; most important inorganic compound in organisms
    • Acids & Bases
    • Acids are hydrogen ion donors (release H⁺ in solution)
    • Bases are proton acceptors (take up H⁺ from solution)
    • Important bases in the body: bicarbonate ion (HCO₃⁻) and ammonia (NH₃)
    • Neutral solutions have pH = 7; pure water is pH neutral
    • Acid solutions contain [H⁺]; pH 0–6.99
      • As [H⁺] increases, acidity increases and pH decreases
    • Alkaline (basic) solutions contain bases (e.g., OH⁻); pH 7.01–14
      • As [H⁺] decreases (or [OH⁻] increases), alkalinity increases and pH rises
  • pH Scale (Representative Values)
    • The scale ranges from highly acidic to highly basic
    • Examples from the figure:
    • 1 M sodium hydroxide (pH = 14) — strongly basic
    • Oven cleaner, lye (pH ≈ 13.5)
    • Household ammonia (pH ≈ 10.5–11.5)
    • Household bleach (pH ≈ 9.5)
    • Egg white (pH ≈ 8)
    • Blood (pH ≈ 7.4)
    • Milk (pH ≈ 6.3–6.6)
    • Black coffee (pH ≈ 5)
    • Wine (pH ≈ 2.5–3.5)
    • Lemon juice; gastric juice (pH ≈ 2)
    • 1 M hydrochloric acid (pH ≈ 0)
    • Concentration concepts depicted in the figure are shown on a log scale from 10⁻¹ to 10⁻¹⁴ etc.
  • Organic Compounds
    • Contain carbon (except CO₂ and CO, which are inorganic)
    • Major classes:
    • Carbohydrates (sugars and starches, e.g., glucose and glycogen) — major cellular fuel
    • Lipids (fats and oils): triglycerides, phospholipids, steroids (e.g., cholesterol)
      • Phospholipids make up the cell membrane
    • Proteins: chains of amino acids joined by peptide bonds; many function as enzymes (biological catalysts) and often end in -ase
    • Nucleic acids: DNA and RNA (involved in protein synthesis); ATP stores chemical energy used by cells
  • Carbohydrates: Three Classes
    • Monosaccharides: simple sugars (e.g., glucose, fructose, galactose, deoxyribose, ribose)
    • Disaccharides: two linked monosaccharides (e.g., sucrose, maltose, lactose)
    • Polysaccharides: long chains of