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Pharmacy is the health profession that links the health sciences with the chemical sciences and it is charged with ensuring the safe and effective use of pharmaceutical drugs. The word derives from the Greek: (pharmakon), meaning "drug" or "medicine". The scope of pharmacy practice includes more traditional roles such as compounding and dispensing medications, and it also includes more modern services related to health care, including clinical services, reviewing medications for safety and efficacy, and providing drug information. Pharmacists, therefore, are the experts on drug therapy and are the primary health professionals who optimize medication use to provide patients with positive health outcomes. An establishment in which pharmacy (in the first sense) is practiced is called a pharmacy, chemist's or drug store. In the United States and Canada, drug stores commonly sell not only medicines, but also miscellaneous items such as candy (sweets), cosmetics, and magazines, as well as light refreshments or groceries.

Thursday, May 3, 2012

Cellular Bioenergetics: ATP and O2

  • Bioenergetics refers to cellular energy transformations.
  • The high-energy phosphate bonds of ATP are a cell's primary source of energy.
  • ATP is generated through cellular respiration, the oxidation of fuels to carbon dioxide and water.
  • The electrons captured from fuel oxidation regenerate ATP via the process of oxidative phosphorylation.
  • The energy available from ATP hydrolysis can be used for
    • Mechanical work (muscle contraction)
    • Transport work (establishment of ion gradients across membranes)
    • Biochemical work (energy-requiring chemical reactions)
  • Energy released from fuel oxidation that is not used for work is transformed into and released as heat.
  • Fuel oxidation is regulated to maintain ATP homeostasis.
  • ΔG0′ is the change in Gibbs free energy at pH 7.0 under standard conditions.
  • Fuel oxidation has a negative ΔG0′; the products formed have a lower chemical energy than the reactants (an exergonic reaction pathway).
  • ATP synthesis has a positive ΔG0′ and is endergonic; the reaction requires energy.
  • Metabolic pathways have an overall negative ΔG0′.
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