Biology Chapter 5: Cell Structure and Function

Chemistry

• Physical vs Chemical Change:

  • Evidence of chemical change:
    • Change in colour
    • Change in odour
    • Formation of a precipitate
    • Gas release (bubbles formed not by heating)
    • Change in temperature or light
  • Differences:
    • Chemical changes are not reversible
    • Physical changes involve changes in shape, form, or appearance

• Atoms vs Ions:

  • Protons are positive, electrons are negative, neutrons are neutral
  • Losing or gaining electrons creates an imbalance of charges, forming ions (number of protons ≠ number of electrons)

• Cations vs Anions:

  • Metals tend to lose electrons to form a full valence shell and become positively charged cations
  • Nonmetals tend to gain electrons to form a full valence shell and become negatively charged anions

• Naming Ions:

  • Metals: add "ion" to the end of the name (e.g., sodium = sodium ion)
  • Nonmetals: add "ide" to the end of the name's prefix (e.g., oxygen = oxide)

• Patterns on the Periodic Table:

  • Periods: rows across the table
  • Groups: columns down the table
  • Period number: represents the number of electron shells
  • Group number: represents the number of valence electrons in the outermost shell

• Ionic Compounds:

  • Formed from positive cations and negative anions bonded through an ionic bond
  • Properties: solid at room temperature, hard, brittle, high melting points; electrolytes

• Naming Ionic Compounds:

  • Metal ion is named first (no change in name)
  • Nonmetal is named second and changes to "-ide"

Biology

• Organelles:
  • Cell Membrane: Separates the cell from its environment; controls the flow of materials; provides support and flexibility
  • Nucleus: Control center; contains DNA; surrounded by a nuclear membrane; controls all functions
  • Nucleolus: Makes ribosomes
  • Chromosomes: Made of chromatids; contain genetic information
  • Mitochondria: "Powerhouse" of the cell; cellular respiration; more energy needed, more mitochondria present
  • Endoplasmic Reticulum: Tunnels and canals connecting the cell membrane and nucleus; helps transport materials
    • Smooth: Involved in the production of fats.
    • Rough: Involved in the production of proteins
  • Ribosomes: Make proteins; can be attached to the endoplasmic reticulum or free-floating
  • Golgi Apparatus: Packages and sorts materials
  • Vacuoles: Storage and support; hold waste, water, food, proteins

Biology (continued)

• Prokaryote vs Eukaryote:

  • Prokaryotes: do not have a nucleus or membrane-bound organelles (e.g., bacteria)
  • Eukaryotes: have a nucleus and membrane-bound organelles (e.g., animal and plant cells)

• Stem Cells:

  • Unspecialized cells that can become any cell type in the body
  • Embryonic stem cells are found in embryos; tissue stem cells are found in adults
  • Blood cell banking uses stem cells

• Cell Cycle:

  • Interphase: growth phase (G1 and G2) followed by DNA synthesis; 90% of cell life
  • Mitosis: nuclear division
    • Prophase: chromosomes condense; nuclear membrane disappears; centrioles move
    • Metaphase: chromosomes line up in the middle of the cell
    • Anaphase: sister chromatids separate
    • Telophase: new nuclear membranes form around separated sets of chromosomes
  • Cytokinesis: division of the cytoplasm

• Cancer Cells:

  • Uncontrolled cell division forming tumors
  • Benign tumors are non-cancerous; Malignant tumors are cancerous and spread to other tissues (metastasis)

Chemistry (continued)

• Chemical Reactions:

  • Substances interact to form new substances
  • Reactants: substances that are used up in the reaction
  • Products: substances that are created
  • Reactions can release energy (exothermic) or absorb energy (endothermic)
  • Law of conservation of mass: Mass of reactants = mass of products
  • Balancing equations: ratio of atoms doesn't change, coefficients can change

• Types of Reactions:

  • Synthesis (combination): A + B → AB
  • Decomposition: AB → A + B
  • Single displacement: A + BC → AC + B
  • Double displacement: AB + CD → AD + CB
  • Combustion: Reaction with oxygen to produce carbon dioxide and water

• Acids vs. Bases:

  • Acids: sour taste; form hydrogen ions in water; react with some metals and carbonates
  • Bases: bitter taste; form hydroxide ions in water; feel slippery; react with acids, turning red litmus paper blue

• pH scale: A logarithmic scale to measure acidity and basicity ; ranges from 0 to 14

• Complete vs Incomplete Combustion:

  • Complete combustion: sufficient oxygen, producing carbon dioxide and water
  • Incomplete combustion: limited oxygen, producing carbon monoxide, and other substances

• Molecular Compounds: Formed when two nonmetals share electrons (covalent bonds)

Biology (continued)

• Digestive System:

  • Function: breakdown of food through mechanical and chemical methods
  • Stages: Ingestion, Digestion, Absorption, Elimination

• Digestive Organs: Describes the function and location of organs like esophagus, stomach, small intestine, large intestine, liver, gallbladder, and pancreas, including processes like mechanical digestion, chemical digestion, absorption, and nutrient transport

• Circulatory System:

  • Function: Transports oxygen, hormones, nutrients, waste products throughout the body
  • Blood: Components: (red blood cells, white blood cells, platelets, plasma)
  • Heart: Chambers, Valves, Pacemaker Cells
  • Blood Vessels: (arteries, veins, capillaries)

• Respiratory System:

  • Function: Provides oxygen; removes carbon dioxide
  • Passage of air through nose, mouth, larynx, trachea, bronchi, lungs, alveoli)

Physics

• Electromagnetic waves: Different types of radiation (radio, microwave, infrared, visible light, ultraviolet, X-ray, gamma)

• Laws of Reflection: Angle of incidence = angle of reflection; light ray, reflected ray, and the normal are in the same plane

• Refraction: Bending of light when it passes between different mediums

• Lenses: Converging vs. diverging lenses (types, behavior of light rays, principal focus)

• Focusing problems: Myopia (nearsightedness), hyperopia (farsightedness), presbyopia