Chapter 1

• Microscope


  Used in biology to look at small things like cells and organelles
• Types of microscopes


  • Light microscopes
  • Electron microscopes
• Light microscopes


  • Cheaper
  • Can see live things
  • Lower resolution
• Electron microscopes


  • Higher resolution
  • Can only see dead things
  • More expensive
• Prefixes for small measurements


  • Nanometer (10^-9 meters)
  • Micrometer (10^-6 meters)
  • Millimeter (10^-3 meters)
• Calculating real size of object

  Size of image / Magnification
• Calculating magnification


  Size of image / Real size of object
• Calculating size of image

  Magnification x Real size of object
• Cell types


  • Animal cells
  • Plant cells
• Nucleus


  Holds the DNA, the brain of the cell
• Cell membrane


  Controls what goes in and out of the cell
• Mitochondria


  Site of respiration, gives the cell energy
• Ribosomes


  Site of protein synthesis
• Cytoplasm


  Gooey substance where chemical reactions happen
• Cell wall


  Gives plant cells rigidity and structure
• Vacuole


  Stores sugars and gives plant cells structure
• Chloroplast


  Site of photosynthesis, contains chlorophyll
• Animal and plant cells are both eukaryotic, multicellular cells
• Other cell types

  • Fungi
  • Bacteria
  • Algae
  • Mycoplasma
• Bacterial cell


  • Has a flagellum to swim
  • Has a spherical nucleoid instead of a nucleus
  • Can do photosynthesis with chloroplasts
  • Has a vacuole to store sugars
• Prokaryotic cells can be identified by features like flagella or nucleoids
• Red blood cell


  • No nucleus to have more space for oxygen
  • Biconcave shape to carry more oxygen
• White blood cell


  • Regular shape to move quickly to infections
  • Can engulf bacteria and viruses
• Muscle cell

  • Has protein fibers to contract
  • Has many mitochondria for energy
• Sperm cell


  • Has a tail to swim
  • Has acrosome to break down egg cell barrier
  • Has many mitochondria for energy
• Xylem cell


  • Made of dead cells to passively transport water and minerals
• Phloem cell


  • Has mitochondria to actively transport glucose up and down the plant
• Root hair cell


  • Large surface area to absorb more water and minerals
  • Has mitochondria for active transport
• Diffusion


  Passive movement of molecules from high to low concentration, no energy required
• Osmosis


  Passive movement of water molecules through a partially permeable membrane, no energy required
• Active transport


  Movement of molecules against a concentration gradient, requires energy from mitochondria