CELLULAR ENERGY GENERATION (4)

• same parents can look diff from each other -they still develop from an unique egg and unique sperm cell that came together
• Cellular energy generation


  All cellular function depends on energy generation and transportation of substances within and among cells
• Adenosine triphosphate (ATP)


  Serves as the chemical fuel for cellular processes
• ATP


  Consists of a nitrogen-containing compound (adenine) joined to a five-carbon sugar (ribose), forming adenosine. Adenosine is joined to three phosphate (or triphosphate) groups
• ATP conversion to ADP

  1. Rupture - ATP is converted to ADP when the terminal high-energy phosphate bond ruptures

  2. Release - Because the third phosphate is liberated, energy stored in the chemical bond is released

  3. Recycle - Mitochondrial enzymes then reconvert ADP and the liberated phosphate to ATP. To obtain the energy needed for this reattachment, mitochondria oxidize food nutrients
• Diffusion


  The net movement of substance traveling down its concentration gradient
• Diffusion


  • It's a form of passive transport—no energy is required to make it happen; it just happens
  • Factors influencing rate of diffusion: concentration gradient, particle size, lipid solubility
• Osmosis


  The passive transport of fluid across a membrane, from an area of lower solute concentration (comparatively more fluid) into an area of higher solute concentration (comparatively less fluid)
• Active transport


  Requires energy, usually moves a substance across the cell membrane against the concentration gradient-from an area of lower concentration to one of higher concentration
• ATP


  Supplies energy for solute movement in and out of cells
• Endocytosis


  An active transport method in which a substance is engulfed by the cell. The cell surrounds the substance with part of the cell membrane, which separates to form a vacuole (cavity) that moves to the cell's interior
• Phagocytosis


  Engulfment and ingestion of particles that are too large to pass through the cell membrane
• Pinocytosis


  Engulfment of dissolved substances or small particles suspended in fluid
• Filtration


  Fluid and dissolved substances also may move across a cell membrane by filtration
• the three R's


  Rupture

  release

  recycle
• no energy is required to make it happen

  passive transport
• low solute concentration


  hypotonic
• higher solute concentration


  hypertonic
• kinds of passive transport

  diffusion and osmosis
• examples of active transport

  the sodium-potassium pump and pinocytosis
• in filtration, pressure (provided by capillary blood) is applied to a solution on one side of the cell membrane. The pressure forces fluid and dissolved particles through the membrane. The rate of filtration depends on the amount of pressure. Filtration promotes the transfer of fluids and dissolved materials from the blood across the capillaries into interstitial fluid.
• several transport methods

  diffusion

  osmosis

  active transport

  endocytosis

  filtration
• adenosine is joined to three phosphate (or triphosphate) groups
• the change from ATP losing its third phosphate to become more stable ADP is an exegornomic process