,abbreviated as Hb, is a protein that has conjugated and a quaternarystructure (Wicher, 2011). It is described as coalesced(protein molecule attached to a non-proteins). In the livingorganisms it is found in the red blood cells. The quaternaryconfiguration has four polypeptide chains brought together. The fourchains fall into the Beta and Alpha categories. Additionally, it hasa prosthetic group, known as the ham, which is made up of an ironatom that is bound to a ring (Wicher, 2011). Naturally, each ham cancombine with one molecule of oxygen. This reaction implies that fourmolecules of oxygen can bind to one molecule of hemoglobin. In thelungs, oxygen binds with hemoglobin to form oxy-hemoglobin.Nonetheless, this process is reversible since when oxygen dissociatesfrom oxy-hemoglobin at the surface of the body cells it goes back tohemoglobin over again. Regarding the critical role it plays in theorganisms’ lives, it is essential to focus on some of its conceptsand how it varies in diverse living things.

OxygenPartial Pressure (PO2)

Oxygenpartial pressure is the level of concentration of oxygen in thesurrounding. The affinity of hemoglobin relies on the degrees ofoxygen. For instance, when the saturation is high, oxygen quicklyloads to hemoglobin to make oxy-hemoglobin but dissociates from thecompound when the levels are low. The gas is introduced into theblood stream through the alveoli in the lungs. The saturation here ishigh thus, it is easily loaded onto hemoglobin (Hadji, 2016). Therespiration process in the body cells makes use of oxygen. Theprocess, therefore, lowers the levels of the gas in the cells. Insuch areas, it unloads from oxy-hemoglobin to the respiring bodycells.

TheEffect of Carbon (IV) Oxide on Dissociation of Oxygen

Thelikelihood of hemoglobin releasing oxygen is high in the regionswhere the partial pressure of carbon (IV) oxide is at heightenedlevels. The increased tendency is because the respiring cells are indire need of oxygen. Literary, the cells are releasing CO2in the respiration process (Hadji, 2016). This reaction subsequentlyraises the concentration of the gas in the cells hence, making iteasier for oxygen to dissociate faster from hemoglobin. This processis known as the Bohr Effect it shifts the dissociation curve to theextreme right. In that context, the saturation of oxygen is lower.

Whencarbon (IV) oxide gets into the red blood cells, it readily convertsto carbonic acid. The acid detaches into hydrogen carbonate andhydrogen ions. While hydrogen carbonate ion diffuses into the plasma,iron hydrogen ones remain, and are washed up by hemoglobin to come upwith hemoglobin acid. It is this formation that prompts hemoglobin todischarge oxygen (Hadji, 2016).

Variationof in Different Organisms

Animalsin High Altitude Areas

Thelevel of oxygen in such zones the partial pressure tends to be lowdue to limited oxygen. The dissociation curve within the regionshifts to the left of the human dissociation curve (Mandi,Shoombuatong, Phanus-umporn, Isarankura-Na-Ayudhya, Prachayasittikul,Bülow, &amp Nantasenamat, 2015). The attraction to oxygen oforganisms that exist in the areas is higher when compared tocreatures in other regions. Consequently, it takes low concentrationsof oxygen to be readily bound to hemoglobin. will alsotend to have low levels of unloading partial pressure (Mandi et al.,2015).

in the Fetus of Mammals

Inthe human fetus, the curve of dissociation shifts to the left of theman`s curve. The shifting implies that the fetus of the mammals hashemoglobin that attracts oxygen efficiently. This efficiency is toenable it to retrieve an adequate amount of the gas for the dividingcells.


Theseorganisms live in conditions where the oxygen levels can get to thelowest. At such occasions, they must make sure that they haveadequate oxygen in their cells. When placed on the dissociation curveof humans, their curve shifts to the left. The curve, therefore,means that their hemoglobin easily combines with oxygen has a lowdissociation rate and the partial pressure required for loading isquite little when compared to other organisms.

Ducksand Mackerels

Theseare fast moving creatures that inhabit areas rich in oxygen. In suchcontexts, the hemoglobin is not adopted to have high levels ofaffinity to oxygen since the environment is ever rich with the gas(Kjeld, 2012).

Unlikeother creatures discussed, their dissociation curve is on the rightside of the man’s curve of dissociation.

Theiraffinity for oxygen is low. The easiness of it binding withhemoglobin is also not high. Besides, the loading and the unloadingconcentration of oxygen are high. The creatures require highersaturation of the gas both to combine and dissociate (Kjeld, 2012).


Therole of hemoglobin in living organisms, particularly in therespiration process, cannot be underestimated. From the discussion,the levels of oxygen and carbon (IV) oxide in the surroundingdirectly affect the rate at which hemoglobin loads and unloads.Consequently, the functioning of hemoglobin varies in organismsdepending on the habitat.


Hadji,B. (2016). Reproducing the Saturation Profile: a Marker ofthe Blood Oxygenation Level Dependent (BOLD) fMRI Effect, at theMicroscopic Level. PLoSONE, 11(3), 1-19.

Kjeld,M. (2012). Allometry (scaling) of blood components in mammals:connection with the economy of energy? CanadianJournal of Zoology, 86(8),890-899.

Mandi,P., Shoombuatong, W., Phanus-umporn, C., Isarankura-Na-Ayudhya, C.,Prachayasittikul, V., Bülow, L., &amp Nantasenamat, C. (2015).Exploring the origins of structure–oxygen affinity relationship ofhuman haemoglobin allosteric effector. MolecularSimulation,41(15),1283-1291. doi:10.1080/08927022.2014.981180.

Wicher,K. (2011). Haptoglobin, a hemoglobin-binding plasma protein, ispresent in bony fish and mammals but not in frog and chicken.Proceedingsof the National Academy of Sciences of the United States of America,103(11), 4168-4173.