Unit 2: Cells and Microscopy

• What is the basic unit of structure for all living things?

  A cell
• What is the cell theory?

  1. All organisms are composed of one or more cells.
  2. The cell is the basic unit of structure and organization of organisms.
  3. All cells come from preexisting cells.
• Electron microscopes use magnets to aim a beam of electrons at a cell to produce an image.
• A prokaryotic cell DOES NOT contain a nucleus and membrane-bound organelles.
• A eukaryotic cell CONTAINS a nucleus and membrane-bounce organelles.
• What is the plasma membrane?

  A thin, flexible barrier between the cell and its environment.
• The plasma membrane allows nutrients to enter the cell and waste to leave the cell.
• What is depicted here?

  Phosphlipid bilayer

  
• What is the function of proteins in the plasma membrane?

  To transmit signals inside the cell, and provide pathways for substances to enter and leave.
• What is the function of cholesterol in the plasma membrane?

  To prevent fatty acid tails from sticking together.
• What is the function of the cilia and flagella?

  Motility and feeding.
• What is the function of the cell wall?

  Provide structure and support to the plant cell.
• What is the function of the centrioles?

  Aid in cell division.
• What is the function of chloroplasts?

  Photosynthesis (energy production)
• What is the function of the cytoskeleton?

  Provide structure for animal cells.
• What is the function of the endoplasmic reticulum?

  Protein synthesis and transport.
• What is the function of the Golgi apparatus?

  Package proteins for distribution outside the cell.
• What is the function of the lysosomes?

  Digestion and breakdown of worn-out cell material.
• What is the function of the mitochondria?

  Creates energy for the rest of the cell through cellular respiration.
• What is the function of the nucleus?

  Control center of the cell; contains coded directions for the production of proteins and cell division.
• What is the function of the ribosomes?

  Protein synthesis.
• What is the function of the vacuole?

  Temporary storage of materials.
• How big is the typical cell?

  25um
• Why are cells small?

  Small cells have a greater surface area to volume ratio, which allows for easier transport of materials and less strain on the nucleus's control of the cytoplasm.
• What is passive transport?

  The movement of particles across the cell membrane without using energy.
• What are the three types of passive transport?

  1. Diffusion
  2. Facilitated diffusion
  3. Osmosis
• What are the three types of transport?

  Passive transport

  Active transport

  Bulk transport
• Passive transport is the movement of particles without using energy.
• What is diffusion?

  Movement of particles from high concentration to low concentration.
• What are three factors diffusion is controlled by?

  Temperature

  Pressure

  Concentration
• What is dynamic equilibrium?

  When the amount of materials inside the cell compared to materials outside the cell has become equal.
• What is facilitated diffusion? 


  Movement of particles across the membrane using proteins.
• What is the difference between channel proteins and carrier proteins?

  Channel proteins remain open always, carrier proteins open and close due to instruction from the nucleus.
• What is osmosis? 


  Diffusion of water across a membrane.
• What are the three types of solutions present in osmosis reactions?

  Isotonic

  Hypotonic

  Hypertonic
• What is a hypertonic solution?

  When there is more solute outside the cell; cell may shrivel.
• What is a hypotonic solution?

  When there is more solute inside the cell; cell may swell.
• What is active transport?

  The movement of particles across the membrane using energy.
• What is the equation for Ratio Quotient?

  High Power / Low Power
• What is the formula for FOV?

  LP FOV / RQ