Hemoglobin is Proof of God II: Carbon Dioxide Transport

If you came to this series of posts hoping to find a rigorous theological debate regarding the existence of an omnipotent power...I'm sorry to disappoint (not really).

Carbon dioxide (CO2) is a metabolic byproduct of aerobic metabolism. Aerobic metabolism is our bodies' primary method of energy generation and it produces a large amount of CO2. This CO2 is released from our bodies into the external environment through our lungs, which will be discussed in a later post. This means that our blood has to transport CO2 from our tissues (e.g. your calf muscle) to our lungs.

There are 3 methods of CO2 transport:

1) CO2, like oxygen, is transported as a dissolved gas in blood plasma. This accounts for 2-10% of our blood's total CO2.

2) CO2 can bind to hemoglobin (and other blood proteins) and be transported to the lungs with the hemoglobin. A single CO2 binds to a single hemoglobin molecule (remember this is different than oxygen, 4 oxygen molecules bind to 1 hemoglobin molecule). This accounts for 5-10% of our blood's total CO2.

3) CO2 can be converted to bicarbonate (HCO3-) by an enzyme called carbonic anyhdrase. The chemical equation for this reaction is: CO2 + H20 -> H2CO3 -> H+ + HCO3-. This reaction is reversible. 80-90% of our blood's CO2 is transported as bicarbonate.

Note: An important concept to understand for future posts will be Le Chatelier's principle
, with regards to concentration, and how it applies to the above equation.

The next post will discuss how gas is exchanged in the lungs.

Hemoglobin is Proof of God I: Oxygen Transport

If you came to this series of posts hoping to find a rigorous theological debate regarding the existence of an omnipotent power...I'm sorry to disappoint (not really!).

Hemoglobin is a protein found in red blood cells. Hemoglobin consists of four subunits and each subunit can bind to a single oxygen molecule. This is the main method of oxygen transportation in our bodies, 98% of our blood oxygen is bound to hemoglobin. If we didn't have hemoglobin, we would die because our organs would suffocate, they would not get enough oxygen (at least you would leave a pretty corpse).

The remaining 2% of the oxygen in our blood is dissolved in the blood fluid (note: if the idea of gasses dissolved in fluid confuses you, think pop (soda for the americans), the bubbles in pop are created because carbon dioxide is dissolved into the drink at the manufacturing plant).

Hemoglobin is, in a sense, a perfect protein. It has several properties that make it an optimal molecule to help with gas exchange. This series will cover several background topics, culminating in a final post explaining these optomized properties.

The next post will discuss carbon dioxide transport in the blood.