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Buffers Post Lab Analysis. ALL LIFE PROCESSES DEPEND ON THIS TINY IONIZATION PROCESS…. Water = nonionic compound. It is converted to ions in a process called ionization. Water separates when one of the OH bonds breaks. This results in a positively charged H+ (hydrogen ion)
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Buffers Post Lab Analysis
ALL LIFE PROCESSES DEPEND ON THIS TINY IONIZATION PROCESS… Water = nonionic compound. It is converted to ions in a process called ionization. Water separates when one of the OH bonds breaks. This results in a positively chargedH+ (hydrogen ion) and a negatively charged OH— (hydroxide ion). Imagine a water molecule that picks up a positively charged hydrogen proton. When this happens, this water molecule becomes positively charged. The water molecule that gave up the hydrogen proton becomes negatively charged because one 1 electron remained behind.
The proton exchange results in 2 water molecules out of every 1 billion splitting into a positively charged H3O+ (called hydronium) ion and a negatively charge OH- (called hydroxide) ion. Pure water, contains hydronium ions equal to 1 x 10-7 moles per liter (0.0000001 moles per liter). In other words, the number of hydronium ions Is equal to number of hydroxide ions.Therefore, the hydroxide ions are equal to 1 x 10-7 moles per liter. This equilibrium between hydronium and hydroxide ions is affected by the addition of substances to water. The level of H+ and OH— ions in solution is known as thepH scale
A proton donor is known as an acid. Acidsincrease the [H+] ions in solution. A base functions as a proton acceptor, it reduces the concentration of [H+] in solution and increases the concentration of [OH--] ions.
1 X 10-1 [H+] = pH 1 HCl or stomach acid 1 X 10-13 [OH--] = pH 1 HCl or stomach acid
pH 1 pH 7 pH 14 [H+] [OH—] What happens to the pH of the solution if the level of [H+] increases? What happens to the pH of the solution if the level of [OH–] increases?
CO2 What does exhaling into the water add to the water? H2O Bromothymol Blue added
CO2 How does this ‘change’ the water? Why? CO2 + H2O H2CO3 CO2 H2O Carbonic Acid
BufferSystems—a buffer is a molecule that tends to either bind or release hydrogen ions in order to maintain a particular pH Bicarbonate Ion Carbonate Ion Carbonic acid What happens when the reactions go to the right? What happens if the reactions go to the left?
H2CO3 = carbonic acid (H+ donor) responds to a rise in pH pH 1 pH 7 pH 14 [H+] HCO3 -- = bicarbonate (H+ acceptor) responds to a drop in pH
Bicarbonate Ion Carbonic acid Maintaining blood pH—why? Acidosis or Alkalosis = death A diabetic’s blood pH dropped to 7.23. Why? The body enters a starving state due to no insulin output; body burns stored fat for energy and ketones are released into the bloodstream as a by-product/or waste product of fat metabolism. Ketones are acidic! What happens during HYPERventilation? Levels of Carbon dioxide decrease; less H+ ions will accumulate causing the pH of blood to increase = alkalosis What happens during HYPOventilation? Carbon dioxide in blood increases; more H+ ions will accumulate causing the pH of blood to decrease
What do the lungs do?In general, acids (H+ ions) are stimulating to neurons. As the carbon dioxide level in the blood increases, it also increases in the cerebrospinal fluid (CSF). This causes the pH to drop; especially in the brain because there is less buffering ability in CSF than in blood. The low pH (excess H+ ions) stimulates neurons in the medullary respiratory centers to fire more impulses to the diaphragm to increase the rate and depth of breathing. What do the kidneys do? Regulates HCO3- ions in blood loss of HCO3- ions in blood = decrease blood pH = metabolicacidosis gain of HCO3- ions in blood = increase blood pH = metabolicalkalosis
pH in the Digestive System, producing HCl Parietal Cells of the stomach secrete HCl into the stomach to disrupt the extracellular matrix and kills most bacteria that are swallowed up with food… HCl converts inactive pepsinogen (which is secreted by chief cells of the stomach) into active pepsin Pepsin begins the chemical digestion of proteins by splitting the polypeptides into smaller polypeptides…
Esophagus “peristalsis” Lumen of the Stomach Small Intestine
H2CO3 = carbonic acid (H+ donor) responds to a rise in pH pH 1 pH 7 pH 14 [H+] HCO3 = bicarbonate (H+ acceptor) responds to a drop in pH
The Stomach—secretion of HCl Movement of molecules by active transport or facilitated diffusion Parietal cell Lumen of stomach Cl- Cl- Cl- + CO2 H2O HCl Capillary Blood vessel Carbonic Acid H2CO3 H+ HCO3- + H+ HCO3- Bicarbonate ion
Carbonic Acid Bicarbonate Hydrogen ion H2CO3 H+ HCO3- + Buffer system in place to regulate pH