topic 1

• What is the structure of an animal cell?

  Contains a nucleus, cytoplasm, and membrane
• What is a characteristic of a bacterial cell?

  It lacks a nucleus and membrane-bound organelles
• What is a unique feature of a sperm cell?

  It has a flagellum for movement
• What is the function of a ciliated cell?

  To move mucus and particles out of the airways
• What are the steps to make a microscope slide?

  1. Take a thin slice of specimen
  2. Add a drop of water on a slide
  3. Use tweezers to add the specimen
  4. Add a drop of stain
  5. Lower a cover slip and press down
  6. Secure the slide on the stage
  7. Choose the lowest powered objective lens
  8. Use coarse focusing knob to adjust
  9. Use fine adjustment knob for focus
  10. Measure diameter of field of view
• What is the equation for magnification?

  Magnification = image size / actual size
• What are the differences between light and electron microscopes?

  Light Microscopes:

  • Inexpensive and easy to use
  • Magnifies up to 2000x
  • Specimens can be living or dead

  
  

  Electron Microscopes:

  • Requires specialist training
  • Magnifies over 500,000x
  • Specimens must be dead and fixed
• What factors affect enzyme activity?

  Temperature, pH, and substrate concentration
• What happens to enzymes at saturation point?

  All active sites are occupied and working
• What is diffusion?

  Movement of particles from high to low concentration
• How does osmosis differ from diffusion?

  Osmosis is the movement of water across a membrane
• What is active transport?

  Movement of particles from low to high concentration
• What are the tests for biological molecules?

  • Reducing sugars: Benedict's reagent, color change indicates concentration
  • Starch: Iodine solution, color change from orange/brown to blue/black
  • Lipids: Shake with ethanol, milky emulsion indicates presence
  • Proteins: Biuret test, purple indicates protein presence
• How do you calculate energy in food using calorimetry?

  Energy (J) = mass of water (g) x temperature change (°C) x 4.2
• How do you calculate energy per gram of food?

  Energy per gram (J/g) = energy in food (J) ÷ mass of food (g)
• What is the purpose of using a calorimeter in experiments?

  • To reduce energy loss to the environment
  • To measure energy changes accurately