Acids, Bases, and Buffers

Question 1

Outline properties of water and its functions in biological systems.

Answer 1

• solvent for compounds in our body.
• transport molecules throughout the body.
• creates intracellular and extracellular environment.
• Homeostatsis
• Thermal regulation of body temperature. *Distribution of heat through body
• Through perspiration
• chemical reactions.

Question 2

Describe a distribution of water between different fluid compartments of the body.

Answer 2

• water occupies two major Compartments:1. Intercellular Fluid (ICF)
  2. Extracellular fluid (ECF) 2 Parts:
• Plasma – the fluid portion of blood
• Interstitial fluid (IF) - fluid in spaces between cells

Question 3

Explain the causes and consequences of disorders of water balance.

Answer 3

-Dehydration:water loss exceeds water intake.
( Profuse sweating,Prolonged diarrhea,Severe burns,
Impaired kidney function){cotton mouth,Dry flushed skin,Mental confusion,Fever}
-Overhydration “Hypotonic hydration”( Leads to water intoxication due to dilution of sodium in ECF resulting in hyponatremia) { Renal insufficiency } Symptoms: nausea, vomiting, cerebral edema, convulsion, coma, and even death.
-Edema is an excessive accumulation of fluid in interstitial space.
Can be caused by:
(An increase in flow of fluids out of bloodstream
-A decrease of their return)
{factors that contribute to fluids loss from circulation:
Increased blood pressure
Congestive heart failure
Decreased blood osmotic pressure
Severely impaired circulation}

Question 4

Explain the major source of hydrogen ions in our body.

Answer 4

We generate CO2 and metabolic acids.

1. CO2 converted to Carbonic acid (co2+H2o), which dissociates into H+ and HCO3-
2. Phosphoric acid into ECF
3. Glycolysis produces Lactic Acid.
4. Fatty acid oxidation produces Ketone bodies.

Question 5

Describe how our body pH is maintained.

Answer 5

-Buffers act within seconds:
Bicarbonate, phosphate, and hemoglobin
-Respiratory center in the brain acts within minutes:
Removes carbonic acid through expiration
-Renal system requires hours to days to affect pH

Question 6

Identify the major buffer systems in our body and understand how they work to maintain our body pH.

Answer 6

1. Bicarbonate-carbonic acid – ECF
2. Hemoglobin buffer system – RBC *intercellular
3. Phosphate buffer system - in all cell types* intercellular
4. Ammonium and phosphate ions – in kidney

Question 7

Describe the control of blood pH by respiration rate.

Answer 7

• If pH falls, the individuals breathe more rapidly – expire more CO2
• If pH rises, the individuals breathe more shallowly – expire less CO2

Question 8

Describe the role of ammonium in the maintenance of urinary pH.

Answer 8

• Ammonium, Major contributor to buffering Urninar pH, NOT BLOOD pH.
• Ammonia is a base (NH3) combines with proton producing ammonia ions (NH4+)

Question 9

Explain the mechanism of intracellular pH maintenance.

Answer 9

• In the cell Phosphate anions and Proteins are Major Buffer of the ICF. H2PO4-( hydrogen Phosphate ion ) dissociates into H+ and HPO4-2
• Hydrogen ions out of the cell is also important in maintaining of ICF pH.
• Metabolic anions are transported outside of the cill Together with H+. * if acid H+ are traded with Na+ ions
• too alkaline more HCO3- is moved out traded with Cl-

Question 10

Explain how bicarbonate buffer system works to maintain physiological pH.

Answer 10

• Carbon dioxide reacts with water to produce carbonic acid, dissociates to H+ and bicarbonate ions, More CO2 reacts with H2O to replenish H2CO3. * CO2 is produced in the cell goes to Interstitial fluid (in between cells ) then to plasma. RBC pass by and pick up CO2 react with H20 to form Carbonic acid, then dissociate to for Hydrogen ion & bicarbonate. the proton binds to Hb HCO3- is transported into blood in exchange for Cl-
• In lung where (co2 is low ) direction reverses.
  cell gets bicarbonate with proton to form carbonic acid to dissociate to co2 ( released to the lung) and H2o

Question 11

Compare the differences between respiratory and metabolic acidosis.
Compare the differences between respiratory and metabolic alkalosis.

Answer 11

-Respiratory acidosis is when someone is choking,asma attack, or COPD.Allowing him not to expel CO2 and therefore increasing CO2 combining with h2o to form carbonic acid dissociating to form protons (up) and bicarbonate.
-Metabolic acidosis : is when someone is producing a lot of protons by tissue (body) and they are hyperventilating, protons are buffered by bicarbonate= carbonic acid, to CO2 and Water.
-RESPIRATORY ALKALOSIS:
hyperventilating patient is exporting co2 in large quantities. blood Co2 is decreased, body produces more co2 by making carbonic acid ( protons + bicarbonate ) and dissociating to form co2 and water. H+ decreases,pH increases, Hco3- decreases co2 increases.
-METABOLIC ALKALOSIS: meaning the blood is getting to basic because the patient is vomiting (throwing up protons) the gastric Mucosa produces excess bicarbonate from co2+H20=h2co3= H+HCO3 to make up for the Hydrogens that were vomited. Hypoventelation to up co2 levels.