9th Grade Cell Transport 

PROKARYOTIC VS EUKARYOTIC

  • Animal, plant, and fungal cells are EUKARYOTIC.
  • Bacterial cells are PROKARYOTIC Eukaryotic cells DO have a nucleus and membrane bound organelles.
  • Prokaryotic do NOT have a nucleus or membrane bound organelles.

THE CELL AND ORGANELLES

  • All living things are made up of cells.
  • All cells come from other cells.
  • The cell is the basic unit of structure and function of all living things Exceptions: Things that were once living and are no longer living; Mitochondria and chloroplasts contain genetic material and can replicate.

CELL TRANSPORT

  • Transport is the circulation or distribution of molecules or substances throughout the cell or from cell to cell.
  • Messages must “fit” the cell receptors (like a lock and key, or enzymes and substrates).
  • The cell membrane is semipermeable, which means means that the membrane only lets in some substances based on the size and the amount of substance

  TWO TYPES OF TRANSPORT

  • Active transport is transport that requires ATP, or energy.
  • Passive transport is transport that requires no ATP, or energy.

  PASSIVE TRANSPORT

  • DIFFUSION moves substance from high to low concentration, and occurs until equilibrium (balance) is reached.
  • OSMOSIS is diffusion OF WATER, ONLY when the WATER itself is moving, not when things are moving IN the water.

CONCENTRATION GRADIENT

  • Concentration the amount of something within a space.
  • Gradient is the change in concentration (high to low or low to high)

  ACTIVE TRANSPORT

  • Active transport brings substances from low to high concentration.
  • When bringing in substances from a low to high concentration, ATP (energy) needs to be used.
  • It is usually a protein to help transport the substance.

  ENDOCYTOSIS: IN

  • Sometimes a material is too large to cross the membrane, so cells use energy to transport these substances in vesicles.
  • The cell membrane folds in, forming a pocket around the substance. The pocket breaks off inside the cell, making a vesicle. The contents of the vesicle are then broken down or released into the cell.

  EXOCYTOSIS: OUT

  • In exocytosis, a vesicle forms around a substance or material in the cell that needs to be removed. The vesicles then goes to the cell membrane, fuses with it, and lets go of the contents.

  SOLUTIONS

  • Solute is the substance being dissolved.
  • Solvent is the one doing the dissolving (usually water).
  • An isotonic solution is when the concentration of solute is equal inside and outside the cell.
  • A hypertonic solution is when there is more solute inside the cell than outside solute will leave the cell and it will shrink.
  • A hypotonic solution is when there is less solute inside the cell and more outside the cell solute will enter the cell and cause it to swell up or bloat.