Difference Between Conjugated Bilirubin and Unconjugated Bilirubin (With Table)

Note: To see the current Epic Deals on Amazon, Click Here

There are two types of bilirubin formed in our bodies. They are Conjugated Bilirubin and Unconjugated Bilirubin respectively. They differ in chemical structure, type, and also function. They are two separate products and vary in their molar weights as well. The increase in the level of bilirubin results in yellow pigmentation. Moreover, it gets deposited in the tissues. This condition is known as jaundice.

To be able to distinguish between the two, knowing their features individually is important. This shall help us to understand the functioning in a better way.

Conjugated Bilirubin vs Unconjugated Bilirubin

The main difference between Conjugated Bilirubin and Unconjugated Bilirubin is their solubility. Conjugated Bilirubin is soluble in water but insoluble in fats. Whereas, Unconjugated Bilirubin is insoluble in water but soluble in fats. Hence, they do have a different solubility status. Moreover, the Conjugated Bilirubin is present in bile but the Unconjugated Bilirubin is not present in it.

Conjugated Bilirubin is defined as the part or fraction of bilirubin that is conjugated with glucuronic acid. The process takes place inside the liver to form bilirubindiglucoronide. It is generally not present in the urine. However, forms high plasma concentration. They can be excreted out of the body directly.

On the other hand, Unconjugated Bilirubin is the part of the fraction of bilirubin that is not conjugated in the liver. It is not soluble in water and is also not present in urine. It is quite toxic to the tissues. Accumulation of Unconjugated Bilirubin leads to severe neuro disorders.

Parameters of ComparisonConjugated BilirubinUnconjugated Bilirubin
SolubilityIt is soluble in water.It is insoluble in water.
ExcretionIt can be excreted out of the body directly.It can not be excreted out of the body directly.
TransportCan travel through the bloodstream without any transport protein.Can travel through the bloodstream only with transport protein.
FiltrationCan be filtered through kidneys.Can not be filtered through kidneys.
BileIt is present in bile.It is not present in bile.

What is Conjugated Bilirubin?

The maximum breakdown procedure takes place in the liver. The breakdown of cytochromes and myoglobin results in the formation of 20 percent bilirubin in our body. The process of conversion of urobilinogen to stercobilinogen takes place in the large intestine.

There is a process of deconjunction of the bilirubin. It takes place in the guts. Almost 20 percent of it is reabsorbed. From there, a specific part of urobilinogen falls into the bloodstream. It eventually gets excreted with urine as a waste product.

An increase in Conjugated Bilirubin might result in the dark color of urine. The color ranges from dark yellow to brown. It can easily pass through the kidney filter and is soluble in water. However, it is insoluble in fats as well as alcohol.

On average, 250-300 mg of bilirubin is produced every day in the body of a human being. The conjugation takes place in the liver. It is the process by which unconjugated bilirubin gets bound with glucuronic acid. The Conjugated Bilirubin formed mainly goes into the duodenum.

What is Unconjugated Bilirubin?

Unconjugated Bilirubin is formed in the reticuloendothelial cells. It can not enter the small intestine along with the bile. The maximum amount of bilirubin is formed due to the breakdown of hemoglobin. It is produced due to the degradation process of the erythrocytes. This contributes to 80 people of the total bilirubin.

It is formed due to the increased breakdown of red blood cells. When the rate is excessive, It accumulates in the bloodstream. Furthermore, it is bound to albumin. The albumin helps to bind the Unconjugated Bilirubin. Jaundice is a condition caused due to the abnormality of bilirubin. It causes yellow discoloration of the skin. Also, Unconjugated Bilirubin causes hyperbilirubinemia in children.

It is insoluble in water. However, it is indeed soluble in fats as well as alcohol. If it is contained in a great amount, it may result in serious bran damages in the long run. The term for such a condition is bilirubin encephalopathy. Sometimes there is a condition known as subicterus where yellow sclera pigmentation is formed. This takes place due to the increased formation of the bilirubin serum.

The Unconjugated Bilirubin gets converted into Conjugated Bilirubin in the liver. If it fails, it is an indication that the liver might not be working properly. Sometimes there is a blockage detected in the bile duct. In this case, excess bilirubin can be removed from our bodies.

Main Differences Between Conjugated Bilirubin and Unconjugated Bilirubin

  1. The most distinct way to distinct between Conjugated Bilirubin and Unconjugated Bilirubin is their solubility. Conjugated Bilirubin is soluble in water. Whereas, Unconjugated Bilirubin is insoluble in water.
  2. Conjugated Bilirubin can be filtered through kidneys. On the other hand, Unconjugated Bilirubin can not be filtered through kidneys.
  3. Conjugated Bilirubin is present in bile whereas, Unconjugated Bilirubin is not present in bile.
  4. Conjugated Bilirubin can travel through the bloodstream without any transport protein. Whereas, Unconjugated Bilirubin can travel through the bloodstream only with transport protein.
  5. Conjugated Bilirubin can be excreted out of the body directly. Unconjugated Bilirubin can not be excreted out of the body directly.

Conclusion

Bilirubin is a product formed due to the degradation of hemoglobin, along with some other components present in the blood. It is pigmented yellow and is present in the liver in the gallbladder bile. It is actually a waste product and is formed due to the breakdown of red blood cells. It ultimately gets excreted out of the body.

Some of it is present in the liver for the production of bile. However, before the excretion, bilirubin is metabolized. For this procedure, first, it needs to get converted into urobilin. This is the reason why our stool is brown in color. A lot of primary factors can cause abnormality in bilirubin.

Reference

  1. https://www.sciencedirect.com/science/article/pii/S0003269700944853
  2. https://www.sciencedirect.com/science/article/pii/S0165178111002228
x
2D vs 3D