Structure and Function of Chromatin – Imaluop

Hi, now we are going to discuss a special structure in the cell, chromatin along with structure and function of chromatin and different methods of analysis of chromatin and its difference with chromosomes. 

Basic Introduction About Chromatin: 

In our cell the genetic material or DNA not only present in its actual double helical molecular form but they present in different types of conformation in which differ types of protein give the DNA different shapes due to their condensation in different ways.

In chromatin DNA, RNA and some associated protein condensed to form a thread like structure and this thread like structure for chromosomes in eukaryotic cells during a certain phase of cell cycle.  

So we can see the thread like structure in the nucleoplasm under the microscope is the result of condensation of DNA, RNA and associated protein in a special way which gives them a thread like appearance and supercoiling of the chromatin produce chromosome and the chromosome is visible in only few stage in cell cycle, other most of the time the genetic material in nucleus present as chromatin.  

Structure of Chromatin: 

Chromatin structure is not fixed in a living cell it should different types arrangements in different phases of cell cycle in some phase they present in very fine threads like structure while in some phase they super coil to make chromosome like structure and in those structure different types of associated protein involved along with the DNA strand. 

In a light microscope we can see bead-like structures along the length of chromatin and they are known as nucleosomes which are results of coiling of DNA with the help of histone protein and the nucleosome further fold to form another structure known as solenoid.

The chromatin fibres fold and coil with the help of some associated protein and finally they produce a super condensed form of chromatin as chromosome and we can see the well developed chromosome in the metaphase stage of the cell cycle. 

Function of Chromatin: 

Prevent Damage in DNA: 

DNA is genetic material in a cell and anything is governed by DNA in a cell so any damage in DNA can affect the cell in different ways. Some damage may not be serious for the cell but some damage causes serious damage in the cell but special coiling of DNA prevents the damage in DNA. 

Accomodation of DNA in Cell: 

If we compare the total length of DNA inside a chromatin fibre with the size of cell then it will give us a very large difference between them. The very long DNA present in a tiny nucleus is only possible due its highly condensation because the condensation makes the DNA small for the nucleus so that the DNA accommodates inside the nucleus. 

Gene Expression: 

The chromatin fibres allow to express the DNA by transcription of a specific portion of chromatin and the chromatin fibres present in different shapes in different phases of cell cycle which is very useful for cell division and duplication of DNA during synthesis phase and even distribution of genetic material in the form of chromosome. 

Basic Differences Between Chromatin and Chromosome: 

Chromatin	Chromosome
Chromatin is a situation of genetic material when DNA is associated with different types of associated protein and forms a beaded fibre-like structure.	Chromosome is a situation of genetic material when the genetic material needs to be present in very high condensed structure then the chromatin fibres coil in different ways to form highly condensed chromosomes.
Chromatin is a very thin fine fibre like structure which is the result of decondensation of chromosomes inside the nucleus and it is caused by hydration of chromosomes.	Chromosome is a thick and short form of genetic material when the chromatin fibres fold and fold again multiple times and are caused by dehydration of water from the chromosome.
If you observe a cell under a microscope then most of the time you will see the genetic material inside the nucleus in the form of chromatin fibres.	In some specific stages of the cell cycle the genetic material occurs as a chromosome in a cell and most of the time in cell chromosome structure is not visible, especially in the metaphase stage the chromosome is visible.

Read More: Examples of Chromosomal Abnormalities