Chemistry Summative Handout
Armin Rahmani, Ahmed Elboraie
Introduction: Blood is a specialized bodily fluid that delivers necessary substances to the
body's cells (in animals) – such as nutrients and oxygen – and transports waste products away from those
same cells.
1) Equilibrium: Oxygen transport
Oxygen is transported around the body in blood by the complex
molecule (hemoglobin), a globular protein which has a central iron
atom. When hemoglobin reacts with oxygen, oxyhemoglobin is
formed. The oxygenation of blood is an equilibrium reaction.
The equilibrium reaction for the transport of oxygen by haemoglobin (Hb) can be represented
as:
Hb(aq) + O2(aq)
HbO2(aq)
OR
Hb4(aq) + 4O2(aq)
Hb4O8(aq)
In the lungs where there is a high concentration of oxygen, by Le Chatelier's principle the
equilibrium position shifts to the right resulting in the formation of oxyhemoglobin.
2) Le Chatelier’s Principle : Alkalosis and Acidosis
Chatelier's principle can be used to predict the effect of a change in conditions on a chemical equilibrium.
The principle is named after Henry Louis Le Chatelier. If a chemical system at equilibrium experiences a
change in concentration, temperature, volume, or partial pressure, then the equilibrium shifts to counteract the
imposed change and a new equilibrium is established.
Hemoglobin (hemoglobin) is involved in series of equilibrium reactions, the overall net result of
these reactions is the equilibrium:
HbH+(aq) + O2(aq)
HbO2(aq) + H+(aq)
Ordinary metabolic reactions result in the formation of several
acids. This increases the concentration of H+, lowering the pH,
and forces the equilibrium position to the left by Le Chatelier's
principle. This is known as acidosis.
During hyperventilation there is a reduction in the concentration
of carbon dioxide so the equilibrium position shifts to the left by Le Chatelier's principle,
decreasing the concentration of hydrogen ions and raising the pH. This is known as alkalosis.
Chemistry Summative Handout
Armin Rahmani, Ahmed Elboraie
3) Buffer Solution: Bicarbonate buffer system
A buffer solution is an aqueous solution consisting of a mixture of a weak
acid and its conjugate base or a weak base and its conjugate acid.
The bicarbonate buffering system is an important buffer system in the acidbase homeostasis of living things, including humans. As a buffer, it tends to
maintain a relatively
constant plasma pH and counteract
any force that would alter it. In this system, carbon dioxide (CO2)
combines with water to form carbonic acid (H2CO3), which in turn
rapidly dissociates to form hydrogen ion and bicarbonate (HCO3- )
according to the reaction below. The reaction is catalyzed by
the enzyme carbonic anhydrase.
Any disturbance of the system will be compensated by a shift in the chemical equilibrium according to Le
Chatelier's principle.
Chemically, electrolytes are substances that become ions in solution and acquire the capacity to
conduct electricity. Electrolytes are present in the human body, and the balance of the electrolytes in
our bodies is essential for normal function of our cells and our organs.
Sodium: Cation (Na+) , Excreted in urine

Regulates water, and provides brain with electrical signals.

Increased sodium (hypernatremia)

A decreased concentration of sodium (hyponatremia)

A Normal blood sodium level is units, 135 - 145 millimoles/liter (mmol/L).
Potassium:

Cation (K+)

Assists cell function

Increase in potassium (hyperkalemia)

Decrease in potassium (hypokalemia)

The normal blood potassium level is 3.5 - 5.0 millimoles/liter (mmol/L).
Chemistry Summative Handout
Armin Rahmani, Ahmed Elboraie
Chloride:

Anion (Cl-)

Helps maintain balance of fluids

Increased chloride (hyperchloremia)

Decreased chloride (hypochloremia)

The normal serum range for chloride is 98 - 108 mmol/L.
Redox Reaction within breathalyzer test



(History) the test was invented in 1953 by Robert Borkenstein, a former member of the Indiana
State Police, and a professor of forensic studies.
There is a direct ratio in the alcohol exhaled by breath, and the concentration in blood. The blood
comes into close contact with the inhaled air within the alveoli. If the blood contains alcohol it
creates equilibrium with the inhaled air.
The air blows into the vial which contains: sulphuric acid, potassium dichromate, water and the
catalyst silver nitrate. The alcohol reacts with the dichromate ion in a redox reaction: 16H^(+) +
2Cr₂O₇^(2-) +3C₂H₅OH -->4Cr^(3+) + 3C₂H₄O₂ + 11H₂O. As the reactions goes to the right there is a
colour change to green, the concentration of alcohol is then determined by the intensity of the
green colour.
Importance of Hemoglobin:

Carrier of Carbon Dioxide and Oxygen

Four polypeptide chains: two alpha chains, each with 141 amino acids and two beta chains, each
with 146 amino acids

Protein portion of each of these chains is called "globin".

Both the a and b globin chains contain primarily a helix secondary structure with no b sheets.

Each a or b globin chain folds into 8 a helical segments (A-H) which, in turn, fold to form globular
tertiary structures. The folded helices form a pocket that holds the working part of each chain, the
heme.

A heme group is a flat ring molecule containing carbon, nitrogen and hydrogen atoms, with a
single Fe2+ ion at the center. Without the iron, the ring is called a porphyrin.
Chemistry Summative Handout
Armin Rahmani, Ahmed Elboraie
Work Citation:
Traverso, M. (January, 2004).The Carbonic-Acid-Bicarbonate Buffer in the Blood. Washington University. Retrieved May
2, 2011, from: http://www.chemistry.wustl.edu/~courses/genchem/Tutorials/Buffers/carbonic.htm
Guyton, C. (2006). Textbook of Medical Physiology (11 ed.). Philadelphia: Elsevier Saunders.
Scorpio, R. (2000). Fundamentals of Acids, Bases, Buffers & Their Application to Biochemical Systems. Washington:
Kendall Hunt Pub.
Charles, E. (March 2004) Respiratory Alkolosis, Elmhurst College Virtual Textbook, Retrieved: May 4, 2011, from:
http://www.elmhurst.edu/~chm/vchembook/263respiratoryalk.html
Casiday, R. (March 2001). Acid-Base Equilibria Experiment, Buffers and pH Regulation During Exercise. Retrieved May 4,
2011, from: http://www.chemistry.wustl.edu/~edudev/LabTutorials/Buffer/Buffer.html
Chemistry Summative Handout
Armin Rahmani, Ahmed Elboraie