You probably know that you need gas exchange to survive, and you can thank hemoglobin for playing a huge role that!
Firstly, where do you find hemoglobin?
Centrifuging a blood sample, you can see that it becomes separated into 3 sections by density:
- 55% Plasma (least dense)
- 1% White Blood Cells and Platelets
- 45% Red Blood Cells
The densest layer consists of red blood cells, the cellular component of blood:
There are roughly 300 million hemoglobin in a singular red blood cell. They are made up of 4 peptide chains/proteins containing 4 heme groups (shown below in different colors),
Each group has an iron ion center in which Oxygen molecules have a high affinity to (total of 4 binding sections):
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It is known that the lungs provide arteries with oxygen to be spread throughout the body using the capillaries.
But how does hemoglobin learn when and where to pick up and drop off oxygen?
When blood reaches the capillaries of the lungs, the high oxygen partial pressure causes hemoglobin to pick up the oxygen and eventually “dump” them at lower oxygen pressures.
Another way for more gas exchange is when muscles are being used, they release carbon dioxide into the blood plasmid. Some CO2 diffuses into the red blood cell, where the enzyme carbonic anhydrase turns it into carbonic acid, which dissociates and releases protons.
Both carbon dioxide and protons bind to hemoglobin, creating allosteric inhibition where both components change the form of the hemoglobin when they bind, making it release more oxygen.
The good thing about this process is that it releases more oxygen when needed.
In a later blog, we will discuss the importance of oxygen in the process of cellular respiration. Stay tuned!
Vocabulary and Key Components:
Plasma
White Blood Cells
Platelets
Peptide Chains
Heme
Affinity
Partial Pressure
Carbonic Anhydrase
Carbonic Acid
Allosteric Inhibition
Cellular Respiration
Hope this helped! Please message me @ scinspiration1@gmail.com or dm me on instagram @scinspiration_
Happy Studying!
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