Unit 2 Slides AY242

Unit 2: Introductory Chemistry Honors Biology

Page 2: Chemistry Overview

  • Definition of Chemistry

    • Deals with chemical and physical interactions of matter.

    • Composed of about 100 different atoms.

Page 3: Atoms

  • Atoms

    • Basic unit of an element for chemical combinations.

    • Most atoms originated from the universe's birth.

Page 4-7: Atomic Structure

  • Composition of Atoms

    • Nucleus at the center with surrounding electrons.

    • Nucleus contains protons (positive) and neutrons (neutral).

    • Electrons (negative) reside outside the nucleus.

  • Electron Movement

    • Electrons are much smaller than protons/neutrons and are in constant motion.

    • Chemical properties depend on the number and arrangement of electrons.

Page 8-9: Subatomic Particles

  • Particle Characteristics

    • Electrons: mass of 9.10 x 10^-28 grams, charge of -1.602 x 10^-19 coulombs.

    • Protons determine chemical identity; electrons determine behavior.

    • Neutrons provide mass and stability.

Page 10-11: Chemical Symbols & Atomic Number

  • Atomic Number (Z)

    • Number of protons in an atom.

  • Mass Number (A)

    • Total of protons and neutrons.

  • Neutral Atoms

    • Equal number of protons and electrons.

Page 12: Isotopes

  • Definition

    • Same atomic number, different mass numbers (different neutrons).

  • Examples

    • Hydrogen isotopes: Protium, Deuterium, Tritium.

    • Iron isotopes: Iron-56, Iron-55.

Page 13: Core vs. Valence Electrons

  • Classification

    • Core electrons: inner electrons.

    • Valence electrons: outermost electrons, involved in bonding.

Page 14-18: Compounds

  • Definition of Compounds

    • Formed when two or more elements combine in definite proportions.

  • Types of Compounds

    • Molecular Compounds: Atoms share electrons (e.g., ammonia).

    • Ionic Compounds: Formed from ions in a 3D network (e.g., sodium chloride).

Page 19-22: Molecular Interactions

  • van der Waals Forces

    • Weak interactions due to electron movement.

  • Water Molecules

    • Polar nature due to charge separation.

  • Hydrogen Bonds

    • Attractive interactions between polar molecules.

Page 23-26: Properties of Water

  • Cohesion and Adhesion

    • Cohesion: attraction between same molecules (surface tension).

    • Adhesion: attraction between different substances.

  • Heat Capacity

    • Water can absorb/release energy with minimal temperature change.

Page 27-29: Mixtures and pH

  • Types of Mixtures

    • Mixtures retain distinct identities; solutions are evenly distributed.

  • Ionization of Water

    • Water can ionize into hydroxide (OH-) and hydrogen ions (H+).

  • pH Scale

    • Indicates H+ concentration; critical for homeostasis.

Page 30-32: Carbon Compounds and Macromolecules

  • Organic Chemistry

    • Study of carbon-containing compounds.

  • Macromolecules

    • Formed via polymerization; four types: carbohydrates, lipids, nucleic acids, proteins.

Page 33-40: Macromolecule Types

  • Carbohydrates

    • Sugars/starches; energy source and structure.

  • Lipids

    • Fats/oils; energy storage and membrane formation.

  • Nucleic Acids

    • RNA/DNA; hereditary information storage.

  • Proteins

    • Enzymes and structural components; formed from amino acids.

Page 41-44: Protein Structure and Chemical Reactions

  • Amino Acids

    • Building blocks of proteins; variable side chains.

  • Peptide Bonds

    • Covalent bonds between amino acids.

  • Chemical Reactions

    • Rearrangement of substances; bonds broken and formed.

Page 45-51: Energy in Reactions and Enzymes

  • Chemical Equations

    • Represent reactions with reactants and products.

  • Energy Dynamics

    • Energy is conserved; breaking bonds requires energy, forming bonds releases energy.

  • Enzymes

    • Specific catalysts that lower activation energy and enhance reaction rates.