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54 Cards in this Set
- Front
- Back
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What % of body is water?
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60%
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pH formula as a function of [hydrogen ion]
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pH = -log [H+]
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A strong acid dissociates what part of its molecule when dissolved in water?
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Hydrogen ions
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pKa formula as a function of Ka
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pKa = -log (Ka)
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A buffering molecule is most effective when working in the pH range closest to ...
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the buffer's pKa
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2 factors regulating the effectiveness of a buffer
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buffer's pKa relative to the solution's pH and the concentration of buffer
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How does ammonia leave the body?
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urinary system
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Why can diabetes lead to ketoacidosis?
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Diabetics cannot allow glucose into their cells to be used. In response, the Liver will break down glycogen into ketone bodies (acetoacetate and B- hydroxybutyrate) and H+. Blood pH drops due to the metabolic products = ketoacidosis
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Acetone gives off what odor?
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Fruity
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Blood pH should be within what range?
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7.34 - 7.44
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After an overnight fast, what are normal blood glucose levels?
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80 - 100 mg/dL
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A casual glucose sample is taken after a meal. Assuming the patient is not diabetic, Glucose levels should never exceed what concentration?
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200 mg/dL is the upper limit for a normal patient
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What type of electrode is used to measure oxygen?
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Clark
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What type of electrode is used to measure CO2?
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Severing
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pH is inversely proportional to concentrations of what basic molecule in the blood (besides H+)?
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CO2
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Compared to normal people, obese people have (more or less) body water?
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less, fat holds less water
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Compared to younger people, older people have (more or less) body water?
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older people have less body water than younger people
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The average hydrogen bond between water molecules lasts how long?
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10 picoseconds (1.0 x 10^-11)
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A water molecule stays in a hydration shell of an ion for how long?
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2.4 nanoseconds (2.4 x 10^-9)
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A hydrogen bond between 2 water molecules is how strong (kcal)
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4 kcal (1/20th strength of O-H covalent bond)
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The covalent bond between O-H is how strong (kcal)?
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80 kcal
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What properties of water allow it to serve as a thermal regulator?
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High heat of fusion (doesn't become ice easily), High thermal conductivity (keeps body warm after tissues use it), High heat of vaporization (cooling effect of sweat),
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When heat is added to a system of water, what is happening to the hydrogen bonds?
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The heat decreases the extent of the H bonding in preparation for evaporation
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Osmolality of blood refers to ...
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concentration of all dissolved solutes in the blood
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Kd of water refers to the ...
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dissociation constant; ([H+][OH-])/ [H2O]
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If a compound has a high Ka, is is a stronger or weaker acid?
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Stronger acid. Ka is directl proportional to the compounds ability to donate a proton
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In the Henderson Hasselback equation, when does pH = pKa?
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When [A-] = [HA]. 50% of the compound is dissociated. Amount of compound dissociated = amount of compound still normal
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What is a stronger acid? A compound with a pKa of 2 or with a pKa of 5?
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Low pKa = high Ka = proton can be dissociated easier = strong acid. pKa = -log (Ka)
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A buffer works best within what range?
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+/- 1 pH of the buffering compounds pKa
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Normal intracellular pH ranges between ...
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6.9 - 7.4 (blood is 7.36-7.44)
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CO2 is a byproduct of what metabolic cycle?
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TCA cycle
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Carbonic anhydrase accelerates the formation of what compound?
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carbonic acid (H2CO3)
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Carbonic acid pKa
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3.5
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Bicarbonate pKa
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6.1
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Carbonic anhydrase is found in what cells?
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RBC. Doesn't exist in plasma (also lung alveoli and kidneys)
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After the dissociation of Carbonic acid into bicarbonate and H+ in the RBC, what happens to the H+?
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H+ can be bound to hemoglobin which is now acting as a buffer. Bicarbonate enters the blood
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After the dissociation of Carbonic acid into bicarbonate and H+ in the RBC, what happens to the Bicarbonate?
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It exits the RBC in exchange for Cl- ions. It is now in the plasma
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As RBCs approach the lungs, what happens to the hemoglobin bound to H+?
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The hemoglobin dissociates H+ to facilitate oxygen binding. This also shifts the equilibrium towards CO2 so it can be released.
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What is Kussmaul's breathing?
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Deep breathing, generally in response to acidosis
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If a cell's intracellular pH was too low, H+ would be pumped out and exchanged with ...
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Na+
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If a cell's intracellular pH was too high, bicarbonate would be pumped out and exchanged with ...
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Cl-
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Urine pH ranges from ....
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5.5 - 7 (5.0 is minimum urinary pH)
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What compound acts as a buffer in the urine?
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Ammonia (NH3)
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Why is ammonia kept at low levels in the blood?
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it is toxic to neural tissue
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Increased ingestion of aspirin tablets leads to what type of blood pH?
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Initially, we see respiratory alkalosis as breathing decreases. But salicylate acid ultimately created metabolic aciosis
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How does Salicylate create metabolic acidosis?
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inhibits mitochondrial ATP production = CO2 generation and lactate in blood
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What is osmotic diuresis?
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Glomerular filtrate solute is so high (as in diabetics due to glucose and ketone bodies) that water moves out of the blood to dilute tubular fluid.
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If a normal person starts hyperventilating, what will happen to their blood pH?
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increases. hyperventilate = more CO2 exhaled = less H+ = more alkaline blood = pH increase
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Is intracellular pH more acidic or basic than arterial blood?
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more acidic due to metabolic by products
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If an acid has a pKa of 4 and is in a solution with a pH of 7, will it be acidic or de-protonated?
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deprotonated. when pKa is less than pH, the acid is dissociated (gives up its proton)
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pKa of ammonium
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9.25
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Which buffering molecule works best for intracellular buffering?
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Phosphate (pKa 6.8-7.2)
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In diabetics, fatty acids may be broken down into ketone bodies in what organ?
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liver
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Pulmonary water loss refers to ...
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excess water exhaled during hyperventilation
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