Question

In detail explain:

-Ferrous vs Ferric in the blood definition, it's conversion, and where it is converted (include the whole process)

The difference between transferrin, ferritin, and hemosiderin. And the process of how they work together for "recycling and elimination of erythrocyte components".

Answer 1

Ferric ion(Fe³⁺) Vs Ferrous ion(Fe²⁺)

Ferric ion and Ferrous ion in blood differs in solubility.When acidity in stomach is low ferric ion is lees soluble when compared to ferrous ion. So ferric ion has to be converted to ferrous for dissolution and absorption in small intestine.

Site of conversion of ferric ion to ferrous ion

Small intestine especially duodenum and jejunum is the site of conversion of ferric to ferrous ion.

Steps of conversion

The conversion steps occurs in ENTEROCYTES (interstinal cells) of duodenal mucosa.

Ferroreductase duodenal cytochrome b which is located on the apical surface of enterocytes of the duodenal mucosa converts ferric iron, (Fe³⁺), in the diet to ferrous iron, Fe(²⁺).

Fe(II) is then transported into enterocytes by the divalent metal transporter (DMT1).

After getting inside ,Fe(²⁺) in enterocytes can be incorporated into the cytosolic iron-storage molecule ferritin or can be transported across the basolateral surface of enterocytes into the plasma by ferroportin.

Fe(²⁺) is subsequently converted to Fe³⁺ by a membrane-associated ferroxidase, hephaestin.

Fe³⁺ Fe²⁺.

Mucosal Fe²⁺  Enterocytes

Fe²⁺ in enterocytes  Plasma

Fe²⁺    Fe³⁺

Transferrin, ferritin, and hemosiderin

Ferritin is a protein that stores iron, releasing it when your body needs it.

Hemosiderin is an aggregate of thousands of ferritin particles, lipids and amorphous protiens

Transferrin is a protein that combines with ferritin and transport it to bone marrow when new red blood cells are made.

How transferrin, ferritin, and hemosiderin work together in Recycling and Elimination of erythrocyte components?

Erythrocytes are formed in red bone marrow. They have a life span of 120 days. After that they are phagocytozed by macrophages in the liver and spleen. Hemoglobin is separated into Globin, iron ion, and heme. Some of the broken down components are recycled, while others are expelled as waste.

-Small amounts of iron are lost in feces, sweat, and urine.
- Some Iron is stored in the liver as ferritin and hemosiderin.
- Some Iron is transported by transferrin into the red bone marrow for erythrocyte production.