Hemoprotein, Hemoglobin, Mioglobin and Iron Deficiency Anemia

Hello, I just finished my second Biochemistry homework, after Biochemistry class, which is my last class of this week. 

And before actually beginning the writing, I want to say, don't take everything I write as true, because I can be horribly wrong, lol. I am in the process of learning, it is things I've never seen before, so I will definetely make mistakes. I am writing this to archive for myself, for the journey and see the progress as it goes, and remember it years later, and also to share a bit with others of what I learned, and what I currently understand at this very moment. It does not mean that I will be 100% right, but I have to learn, and I will learn with my mistakes. So again, don't take my writings as the true thing. If you want to know more about something, research it for yourself in case I am indeed wrong, lol (which I'll probably be most likely).


After learning about how proteins become a, well, protein, today we learned about one of their functions; a group called hemoprotein. 

First, to become a protein, you have aminoacids. Aminoacids are structured like this: 
You have a chiral carbon (C), an amino group (NH2), carboxyl group (COOH), hydrogen (H) and a side chain/variable group. 
That side chain is going to determine what aminoacid it will be (Example, an H on the side chain means that that's a Glycine). 

A sequence of aminoacids will form the primary structure, this kind of bond is called "peptide bond"
The secondary structure is made of hydrogen bonds and will make the structure form either a Beta-Sheet or an Alpha-Helix. The hydrogen bonds help stabilize the structure. 
The tertiary structure are bonds that depends on the side chains of the structure. It will give the protein structure a 3D look. 
Quaternary structure is a bond between two or more polypeptidic chains (or subunits, whatever you call.)

So that is how from a sequence of aminoacids it becomes a protein on the final structure (although some can stop at the tertiary structure [apparently]) 

Now, about a hemoprotein, it is basically a protein that has a heme prosthetic group. 

The Heme is a ring shaped molecule that has an iron on the middle of it. 
The Heme structure is described as: 
Porphine: of four pyrrole rings connected by four methine bridges. 
And the Porphyrin but I'm still not confident to explain its structure. 
May contain Hys aa residues depending on the kind of heme (I think!!!!) 
The iron is at the middle of the structure. 

A hemoglobin has as its last structure, the quaternary structure. It has four polypeptide chains, in each subunit, there is a heme prosthetic group. So that means, each hemoglobin will carry 4 molecules of oxygen. 

The mioglobin has a similar aspect but the structure is different and I don't feel fit to explain it, but it is a very important protein found on muscles, as it carries oxygen to said tissues. It is most abundant in marine mammals. 


Back to the hemoglobin, it has two conditions: Oxy and desoxy. 
Oxy means that the iron on the heme group connected to an oxygen molecule.                    Desoxy means that the iron is no longer connected to an oxygen molecule.
This changes the appearence of the structure very slightly when it conects but goes back to normal when it disconnects from the oxygen. 

Our teacher gave us a homework for the weekend which I already finished, about a clinical case of a very energetic and playful dog that suddenly had symptoms like lethargy and exercise intolerance. Upon a veterinary visit, on the clinical exam, the dog presented tachycardia, which means that its heart rate is exceeding normal heart resting rate. 
After that, the veterinary doctor requested a Complete Blood Count (CBC).
The results came back altered.
The dog had Microcytosis, which means that its red blood cells are unusually small.
It also had Hypochromia, which means his red blood cells are paler than normal. 

As I was reading the symptoms and the tachycardia, microcytosis and hypochromia came up, I thought it was some kind of Anemia. 

The reason the dog presented tachycardia is because, since his blood cells are pale and small, it has trouble capturing oxygen and transporting it to various bodily tissues, so the heart tries to compensate the lack of oxygen rich blood by pumping way too fast. 

In this case, I figured it also had to do with iron deficiency, so the best treatment would be iron supplementing and iron rich foods, and of course, keep close eye on the dog for any signs of worsening condition or better. 

I felt very pleased that I was able to understand, in a biochemistry way, how is everything related. Why those symptoms are like that, how, what is the issue and how to treat it. 

Well, for now, it is this. 

I will go to my anatomy tutoring now. See you.