Cell Biology and Human Body Systems

Cell Biology

• Cell Theory: All living things are composed of cells; cells are the basic unit of life; all cells come from pre-existing cells.
• Prokaryotic Cells: Lack a nucleus (e.g., bacteria).
• Eukaryotic Cells: Possess a nucleus (e.g., plant, animal, fungal cells).
• Cell Structures:
  • Nucleus: Controls cell functions, holds DNA.
  • Cytoplasm: Jelly-like substance, site of chemical reactions.
  • Mitochondria: Produces energy (powerhouse).
  • Ribosomes: Synthesize proteins.
  • Cell Membrane: Regulates what enters/exits the cell.
  • Chloroplasts (plant cells): Site of photosynthesis.
• Cell Division:
  • Mitosis: Creates two identical daughter cells (body cells).
  • Meiosis: Creates four non-identical daughter cells (sex cells).

Tissues, Organs, and Systems

• Levels of Organization: Cells → Tissues → Organs → Organ Systems → Organism
• Human Body Systems:
  • Circulatory: Transports nutrients, gases, wastes.
  • Digestive: Breaks down food, absorbs nutrients.
  • Respiratory: Takes in oxygen, expels carbon dioxide.
  • Nervous: Controls and coordinates body activities.
  • Excretory: Removes waste products.

Reproduction

• Asexual Reproduction: One parent cell creates offspring (e.g., binary fission in bacteria).
• Sexual Reproduction: Two parents involved; creates genetically diverse offspring.

Chemistry: Matter and Chemical Reactions

• Properties of Matter:
  • Physical Properties: Observed without changing the substance (e.g., color, melting/boiling point).
  • Chemical Properties: Describes how a substance reacts with others (e.g., flammability).
• States of Matter: Solid, liquid, gas; temperature and pressure impact state changes.
• Atomic Theory:
  • Atom Structure: Nucleus (protons, neutrons); electron shells.
  • Periodic Table: Organizes elements by atomic number.
    • Groups (vertical columns): Similar properties.
    • Periods (horizontal rows): Changing properties.
    • Metals, non-metals, metalloids.
• Chemical Bonding:
  • Ionic Bonding: Between metals and non-metals, electron transfer.
  • Covalent Bonding: Between non-metals, electron sharing.
• Chemical Reactions:
  • Synthesis: Two or more substances form a new one.
  • Decomposition: A substance breaks down into simpler substances.
  • Combustion: Reaction with oxygen, releases energy.
  • Single Displacement: One element replaces another in a compound.
  • Double Displacement: Ions exchange between two compounds.
• Balancing Chemical Equations: The Law of Conservation of Mass; equal number of atoms of each element on both sides of the equation.

Physics: Motion, Forces, and Energy

• Motion:
  • Linear Motion: Movement along a straight line.
  • Rotational Motion: Movement around an axis.
  • Speed: Distance/Time.
  • Velocity: Speed in a given direction.
  • Acceleration: Change in velocity/Time.
• Forces and Energy:
  • Newton's Laws of Motion:
    • 1st Law: Inertia: Objects stay in their state of motion unless acted upon by a force.
    • 2nd Law: Force = Mass × Acceleration (F = ma).
    • 3rd Law: Action-Reaction: Equal and opposite forces.
  • Work: Force × Distance.
  • Kinetic Energy: Energy of motion (½mv²).
  • Potential Energy: Stored energy due to position (mgh).
  • Conservation of Energy: Energy cannot be created or destroyed.
• Waves and Light:
  • Types of Waves: Transverse (e.g., light), Longitudinal (e.g., sound).
  • Wave Properties: Wavelength, frequency, amplitude.
  • Light and Optics:
    • Reflection: Light bouncing off a surface.
    • Refraction: Light bending as it passes between mediums.
    • Lenses: Convex (converging), concave (diverging).