| Term | Definition |
| Hydrogen Ion Activity | -efficient biochemical and enzymatic processes demand an exacting cellular environment
-Free [H+] is measuered in plasma |
| Hydrogen Ions | -among most important factors in the cellular environment
-affect all physical and biochemical cellular phenomena
-increases acidic value of solution |
| pH stands for | -Power of hydrogen
-Potential Hydrogen
-Logarithmic value of the reciprocal of the [H+]
-4 x 10^8 moler per liter (.00000004) |
| Ways to Express pH | - - log (4 x 10^8) or (0.00000004)
- -(-7.3979)
- 7.40 (normal) |
| 3 Descriptions of pH | - [H+]
-Negative log of the [H+]
-Log of the reciprocal of the [H+] or inversely proportional to the [H+] |
| Components that affect the pH | -Respiratory Component (PCO2)
-Metabolic Component (HCO3-/Bicarb) |
| Respiratory Component (PCO2) | -acid
-pCO2 has an inverse affect on pH
-increased pCO2 increases the acidic value of a solution [H+] |
| Metabolic Component (HCO3-/Bicarb) | -base
-HCO3- has a direct affect on pH
-increased HCO3- increases alkalotic (basic) value of solution [H+]
-HCO3- wants to bind to hydrogen so it eliminates free floating H+ |
| Acids | donate hydrogen ions (protons) |
| Bases | accept hydrogen ions (protons) |
| Metabolism Aggregate of all chemical processes that result in: | -growth
-energy production
-elimination of waste
-other bodily functions as they relate to the distribution of nutrients in th blood after digestion |
| Two phases of Metabolism | -Catabolism
-Anabolism |
| Catabolism | -destructive phase
-larger molecules are converted to smaller molecules
-decomposition reactions
-breaks down nutrients
-produces energy (exergonic) |
| Anabolism | -constructive phase
-smaller molecules are converted to larger molecules (synthesis)
-growth and repair
-consumes energy (endergonic) |
| What does Metabolic Rate Determine? | -quantity of CO2 produced and enters the blood |
| What does Lung Function Determine? | -quantity of CO2 excreted from the blood |
| Sources of Energy | -Carbohydrate Metabolism: Main source of energy
-Lipid/Fate Metabolism: used if carb metabolism is deficient
-Protein Metabolism: "last resort energy" |
| Carbohydrate Metabolism | -final products of digestion include glucose, fructose, and galactose |
| Glucose | -95% of blood sugars produced
-stored as glycogen or fat
-converted back to glucose as needed
-carried through cell membranes by proteins that are aided by insulin |
| Glycolysis | -metabolic pathway that converts glucose to energy
-aerobic metabolism
-anaerobic metabolism
-CO2 is a waste product |
| Aerobic Metabolism yields what? | -pyruvic acid |
| What does Anaerobic Metabolism yield? | -lactic acid |
| Incomplete oxidation of Carbohydrates | -can be caused by stress & Exercise
-both aerobic and anaerobic metabolism yield ATP and H+
-H+ are used in oxidative phosphorylation to produce more HTP |
| What can reverse Incomplete Oxidation of Carbohydrates? | -increased O2
-Decreased activity
-Decreased metabolism |
| Iipids(fats) Metabolism | -fats are stored or used as energy for the body
-if carbohydrate metabolism is deficient, more fat will be used
-Acetoacetic Acid (typd of keto acid) is waste product |
| Protein Metabolism | -O2 transport
-Enzyme function
-Aid in muscle contraction
-catabolized into amino acids
-used as a last resort for energy
-NH3 (ammonia) is a key waste product |
| Respiratory Quotient (RQ) | CO2 produced/O2 consumed
-80% is normal |
| What accounts for nearly all the O2 consumption of the body? | -Oxidation of carbohydrates and fats
-major sources of energy for the body |
| Metabolism of Carbohydrates RQ | -1 mole O2 consumed
-1 mole CO2 produced
-RQ = 100% |
| Metabolism of Fats RQ | -1 mole of O2 consumed
-0.7 moles CO2 produced
-RQ = 70% |
| Metabolism of Proteins RQ | -1 mole of O2 consumed
-0.7 moles of CO2 produced
-RQ = 70% |
| Where is CO2 carried? | -plasma 5%
-RBC 95% |
| Plasma CO2 | -dissolved CO2 accounts for most CO2 carried in plasma
-0.1% reacts with water for form H2CO3 (hydrolysis or hydration)
-difficult to distinguish between dCO2 and H2CO3 |
| Plasma CO2 Hydrolysis equation | -very slow
-carbonic anydrase (enzyme) is not present |
| Total dCO2 plasma | PCO2 x 0.003 |
| Solubility coefficient of CO2 | 0.003 |
| Total dCO2 | -value used to represent H2CO3 in Henderson-Hasselbach equation |
| Dissolved CO2 | accounts for 8% of total CO2 released in the lungs |
| CO2 Transport in the RBC | -80% of CO2 is transported as bicarbonate (HCO3-)
-hydrolysis occurs very rapidly due to carbonic anhydrase
-12% of CO2 chemically combines with amino acids contained within the hemoglobin forming carbaminohemoglobin
-This process produces H+ |
| The relationship between CO2 and hemaglobin | -CO2 has a higher affinity for Hemoglobin and kicks the hydrogen off which increases the content of H+ in the blood and decreases pH |
| Chloride Shift | -HCO3 diffuses into plasma due to concentration gradient between RBC and plasma
-CL ions enter RBC to maintain electroneutrality |
| CO2 and Metabolism | -Metabolic rate determines CO2 production
-PaCO2 changes with rate of CO2 production when alveolar ventilation is constant |
| CO2 Elimination | -Ventilation determines rate of CO2 Elimination
-Hyperventilation: high rate and/or volume
-Hypoventilation: low rate and/or volume |
| How long does it take pH to adjust in the Respiratory System? | 1-3 minutes
change in rate and/or volume breathing |
| Ventilation and Acid-Base Physiology | PCO2 = 1/Alveolar ventilation |
| Hemoglobin | -oxygen carrying protein in the RBC
-each molecule contains 4 molecules of Fe+
-each Fe+ molecule can reversibly bind to 1 molecule of O2
-Major buffer due to reversible binding with H+
-also binds with CO2 |
| Bohr Effect | -Right shift in Curve
-Decreased Hb affinity for oxygen
-increase H+
-decrease pH
-increase CO2
-Increase Temp
-Increase 2-3 DPG
-O2 becomes more available and is released into tissue cells |
| Hb in Bohr Effect | -more capable of binding H+ to amio acids in Hb
-slightly alters structure of Hb
-Decreases ability of Hb to carry O2
-Increases blood's ability to carry CO2 |
| Haldene Effect | -addition of O2 to the blood enhances CO2 release from Hb
-Left Shift in Curve
-Increases Hb affinity for oxygen
-decrease H+
-Decrease CO2
-Decrease Temp
-Decrease 2-3 DPG |
| Metabolic Acid-Base Physiology | -regulated by kidneys
-controls excess of H+ or HCO3 through buffers |
| Kidneys | -HCO3- is reabsorbed into the blood
-H+ is excreted into urine
-total amount of hydrogen ions excreted are significant to metabolic acid-base balance
-cannot produce urine with a pH below 4.4 |
| How often does Free H+ urinary acid secretion occur? | less than 1% of the time |
| What accounts for excretion of most nonvolatile acids? | phosphate and ammonium urinary buffers |
| Carbonic anhydrase in Renal Tubular cells | -H2CO3 is rapidly dissociated into H+ and HCO3-
-HCO3- must react with H+ before it can be reabsorbed as CO2 |
| Renal Correction of Acidosis | -excess H+ is excreted in urine
-HCO3- binds with Na+ to form NaHCO3
-NaHCO3 is then reabsorbed into the blood |
| Renal Correction of Alkalosis | -excess of HCO3- relative to H+
-HCO3- cannot be reabsorbed without reacting with H+
-Excess HCO3- is excreted in urine |
| Buffering Systems | -prevents drastic changes in pH of a body fluid
-converts strong acids and bases into weak acids and bases |
| Significant deviation from normal pH range | -poorly tolerated
-May be life threatening |
| Chemical Equilibrium | -Rate of reaction of a substance in one direction is equal to the rate of reaction in the opposite direction |
| Isohydric Principle | -any condition tha causes [H+] to change causes balance of all buffer systems to change at the same time
-buffer systems buffer each other
-any condition that chanegs balance of any one of the buffer systems also changes balance of all the others |
| Major Buffering Systems | -Hb
-Kidneys |
| Types of Buffer Systems | -RBC
-HCO3-
-Phosphate (HPO4)
-Ammonia (NH3-) |
| RBC Buffering | -Carried out by Hb
-Hb binds reversibly with H+ |
| HCO3- Bicarb Buffer | -found in plasma, RBCs, renal tubules
-HCO3- binds with H+ forming H2CO3
-H2CO3 is then converted to CO2 and H20 |
| Phosphate (HPO4) Buffer | -renal buffer
-sodium phosphate (Na2HPO4) is highly concentrated in tubular fluid
-excess H+ takes the place of Na+ to form NaH2PO4) (sodicum acid phosphate)
-NaH2PO4 is excreted in urine
-Freed Na+ binds with HCO3- and is reabsorbed as NaHCO3 |
| Ammonia (NH3-) Buffer | -NH3- is located in tubular fluid
-excess H+ binds wtih NH3- and a CL- ion to form NH4CL (ammonia chloride)
-NH4CL is excreted in urine
-HCO3- binds with Na+ and is reabsorbed |
