Membrane and Transport

• Passive Transport


  The movement of material through a cell membrane without using energy.
• Concentration of a Substance


  The amount of a substance in a given volume.
• Diffusion


  The process by which molecules move from an area of high concentration to low concentration.
• Osmosis


  The diffusion of water molecules through a selectively permeable membrane.
• Active transport


  The movement of substances through a cell membrane using energy.
• Why are cells small?

  Cells are small so that substances can move through the cell in a reasonable time.
• Eukaryotic Cell


  A cell that has a nucleus.
• Prokaryotic Cell


  Cells that do not have a nucleus.
• Organelle


  A tiny cell structure that carries out a specific function within the cell.
• Cell Membrane


  A cell structure that controls which substances can enter or leave the cell; like the screen on a window.
• Water moves out of the cells of a salt water fish and into the ocean. Osmosis or Diffusion

  Osmosis
• Oxygen moves from the lungs into the blood stream. Osmosis or Diffusion

  Diffusion
• Explain how osmosis differs from diffusion.

  Diffusion is the process by which molecules move from an area of high concentration to low concentration.

  Osmosis is the diffusion of water molecules through a selectively permeable membrane.
• State one reason that cells are small.

  Cells are small so that substances can move through the cell in a reasonable time.
• SELECTIVELY PERMEABLE means letting some but not all substances pass through. T or F

  TRUE
• OSMOSIS is the process by which molecules tend to move from an area of higher concentration to an area of lower concentration. True or False

  FALSE: DIFFUSION
• The process by which water moves across a selectively permeable membrane is called DIFFUSION. True or False

  FALSE: OSMOSIS
• Diffusion and Osmosis are both kinds of ACTIVE TRANSPORT. True or False

  FALSE: PASSIVE TRANSPORT
• PASSIVE TRANSPORT requires energy. T or F

  FALSE: ACTIVE TRANSPORT
• A Red Blood Cell placed in fresh water will probably burst. True or False


  True
• Exocytosis helps a cell get rid of waste. True or False

  True
• How does exocytosis differ from endocytosis?

  In endocytosis materials are brought into the cell while in excocytosis they are eliminated from the cell.
• Exocytosis and endocytosis are examples of passive transport. True or False


  False. Active transport because these processes require energy.
• What cell structure is most responsible fro maintaining homeostasis in the cell?

  The Cell Membrane
• If the sides of the cell are doubled the surface area increases _______ times.

  Four
• If the sides of the cell are doubled the volume increases _______ times.

  eight
• Starch is stained a dark color by this chemical.

  Lugol's or Iodine
• Shivering and perspiring are involved in:

  Thermoregulation, Osmoregulation or Chemoregulation

  Thermoregulation
• Concentrated Urine is due to: Thermoregulation, Osmoregulation or Chemoregulation.

  Osmoregulation
• In a phospholipid the tails are: hydrophobic or hydrophilic

  hydrophobic
• What do membrane proteins do?

  Form openings that allow materials to cross the membrane that can't easily cross the lipid bilayer.
• Maintaining a stable internal environment.

  Homeostasis