The term Gene is something we hear everywhere now a days,whether its biotechnology or Genetic engineering,the gene forms the base of all these rapidly developing field of science.Now we live in an era of biologically modified food and other such products and the modification occurs at the genetic level.So What actually is this gene?Where is it located? and moreover how it works?.These questions are answered by this article and i have tried to use minimum technical terms so that any common man can understand.Also here i believe that the readers have some basic knowledge about cells and its parts.
What is a gene?
To understand what a gene is, we need to understand some basic facts about cells and Deoxyribonucleic Acid (DNA).We all know that every organism is made up of cells and each cell have different organelles in it.Here we need to consider the most important organelle of a cell which is called nucleus.Inside the nucleus we have something called chromosomes,which are nothing but DNA coiled and kept compressed.Now what is this DNA?DNA is the genetic material or molecule present in a cell which form the bases of all the activities of a cell.It is heredity materials which we inherit from both father and mother.During the formation of first cell by the process of fertilisation,half of this genetic material come from sperms(male contribution) and the other half from egg or ova(female contribution).The first cell called the zygote thus formed get a unique genetic material.When this single cell divide, an exact copy of the DNA or genetic material goes to the daughter cells.In all subsequent divisions this copy process take place and thus each and every cell of an organism has an exact copy of its genetic material,or in other words every cell has its own DNA which are identical.Now we have to understand the structure of DNA.DNA is like a spiral staircase basically made up of 4 nucleotides.To know more about the chemistry of nucleotide and DNA you can search it,but for the time being,lets take the four nucleotides as four letter A,T,C and G.(Adenine,Guanine,Thymine,Cytosine).These letters can be called as four letters of life.So now DNA is made of these four letters,just like its shown in the picture.The arrangement of these letters follow specific rules like A will bond only with T and C will bond only with G.Also you must understand that there are two strands for DNA.So i believe now you have a rough idea about the structure of DNA.That is enough to understand the concept of gene.
Now what is a gene.In a very common and basis explanation,Gene is a part of DNA.Yes,a specific region in DNA which has got a specific role.It doesn't mean that if we take a piece of DNA it will be a gene.It means that gene is a part or piece of DNA with specific function or work to do.Now what is that work is explained below.
How does gene work?
We have already seen what a gene is.To know what gene do, first we have to understand that gene working is not the correct term to use.A gene is not working instead it express.There is a huge difference between the two words.The gene express, which means that gene is nothing but a blueprint or a message like 'How to do'.So the next question.A blueprint for what?The answer is protein production.
We know that almost every function of body is done by proteins.Proteins are enzymes,hormones,regulatory factors and everything.,you name it.So the prime need or function of body is to make proteins.So what are proteins made of?Proteins are made up of its building blocks called amino acid.There are 20 amino acid in total.When we eat a protein substance,during digestion from stomach,they are broken down to amino acids.Now body has got an amino acid pool.To make a protein needed for the body,say an enzyme,our body has to arrange that amino acids in specific pattern so as to make that enzyme.The body mechanisms has to know the correct sequence of amino acid to be arranged to make a specific protein.So how does the body know the sequence,where is it written?.Your guess is correct.The genes are the message or blueprint for protein production.The genes have the message as to how the amino acids are to be arranged to make a protein.The nature has written the message in gene.How amazing!,isn't it?
There are two process by which this message in gene is converted into a protein molecule by the arrangement of amino acid.They are called Transcription and Translation.But that is a very complicated process and now all we need to understand is corresponding to the arrangement of letters in the part of DNA(gene),the body arranges amino acids and make the proteins it needs.Thus almost all the functions of body are maintained and regulated.Here i like to make a little point that,proteins which are made by this process directly doesn't enter into action.It will have to undergo many modification inside the cells.But in any way the first step in protein production is the conversion of this message.
Thus in short,a gene is a part of DNA which carry a message (blueprint) for the production of proteins.The proteins control all the activities of the body.Here i have explained the basic concepts in a very simplified way and you must understand that there are very complicated mechanism of body which makes this into reality.They are to be understood separately and detailed study about it is the need of a student of genetics!