PROTEINS

The word proteins is the most heard term in the study of dna and genes. so what is protein???

It is one of the fundamental material in the structure of most living things.Proteins are the organic compounds made of amino acids arranged in a linear chain and folded into a globular form.Like other biological macromolecules proteins are essential parts of organisms and participate in every process within the cells.

Proteins are assembled from amino acids using information encoded in genes.Each protein has its own unique amino acid sequence that is specified by the nucleotide sequence of the gene encoding this protein.The process of synthesizing a protein from an mRNA template is known as translation.So Proteins are the chief actors within the cell, said to be carrying out the duties specified by the information encoded in genes.They are one of the building blocks in the cell.And also proteins serve as enzymic catalysts also.And proteins are important for regulating physiological processes, energy production within the body's structure.

GENOME ANNOTATION

Genome annotation is defined as the process of identifying the locations of genes and all of the coding regions in a genome .Here annotation indicates a note added by way of explanation or commentary. Once a genome is sequenced, it needs to be annotated to make sense of it.So genome annotation is the process of attaching biological information to sequences.

This process is of two steps:

1- identifying elements on the genome.

2- attaching biological information to these elements.

This field is an active area of investigation and involves a number of different organizations in the life science community which publish the results of their efforts in publicly available biological databases accessible via the web and other electronic means and a variety of software tools have been developed to permit scientists to view and share genome annotations.If we go further deep into this field we have again two types: structural annotation and functional annotation.

COMPARATIVE GENOMICS

Comparative genomics is the analysis and comparison of genomes from different species. The purpose is to gain a better understanding of how species have evolved and to determine the function of genes and noncoding regions of the genome.It involves the use of computer programs that can line up multiple genomes and look for regions of similarity among them.So this field aims to take advantage of the information provided by the signatures of selection to understand the function and evolutionary processes that act on genomes.It studies both the proteins,RNA and regulatory regions of different organisms.One of the important goals of this field is the identification of the mechanisms of eukaryotic genome evolution.SO this field is also a fascinating one and also exciting.It is a new field of biological research.The information provided by this field helps scientists for better understanding of the structure and function of human genes and thereby develop new strategies to combat human disease.

BIOINFORMATICS

This is one of the fascinating and growing fields at present.Actually bio informatics is the application of information technology and computer science to the field of molecular biology.It is the science of using computer technology to gather, store, analyse and merge biological data.And it also deals with the gathering of data from genomic analysis into accessible and usable forms.SO in brief we can say that bioinformatics is the science of developing computer software and algorithms to record and analyze biology related data, eg gene, protein, metabolic pathways and active drug ingredients data.Bioinformatics now entails the creation and advancement of databases, algorithms, computational and statistical techniques and theory to solve formal and practical problems arising from the management and analysis of biological data.Common activities in bioinformatics include mapping and analyzing dna and protein sequences, aligning different DNA and protein sequences to compare them and creating and viewing 3-D models of protein structures.The main goal of bioinformatics is to increase the understanding of biological processes.Bioinformatics was applied in the creation and maintenance of a database to store biological information at the beginning of the "genomic revolution", such as nucleotide and amino acid sequences.

MAIN FUNCTION OF GENES

The main function of genes is to provide the information needed to make molecules called proteins in cells.Proteins are made of a chain of 20 different types of amino acids molecules.The information in DNA is held in the sequence of the repeating units along the DNA chain. These units are four types of nucleotides((A,T,G and C) and the sequence of nucleotides stores information in an alphabet called the genetic code. When a gene is read by a cell the DNA sequence is copied into a very similar molecule called RNA.If the sequence of the nucleotides in a gene changes, the sequence of the amino acids in the protein it produces may also change - if part of a gene is deleted, the protein produced will be shorter and may not work any more

GENE REGULATION

Gene regulation is a process in which a cell determines which genes it will express and when it will take place.This term can also be said as regulation of gene expression.So this process is essential for viruses,prokaryotes, and eukaryotes.The first discovered example of a gene regulation system was the lac operon in which protein involved in lactose metabolism are expressed only in the presence of lactose and absence of glucose.Furthermore, gene regulation drives the processes of cellular differentiation leading to the creation of different cell types in multicellular organisms where the different types of cells may possess different gene expression profiles though they all possess the same genome sequence.

PHYLOGENETICS

Phylogenetics is the field of biology which deals with identifying and understanding the relationships between the many different kinds of life on earth. This includes methods for collecting and analyzing data, as well as interpretations of those results as new biological information.Going into the details phylogenetics is the study of evolutionary relation among various groups of organisms which is discovered through molecular sequencing data.But the problem posed by this field is that genetic data are only available for the present, and fossil records are less reliable.But nevertheless this field is a very fascinating field to explore and study.

DNA METHYLATION

A chemical modification where a methyl group is added to a stretch of DNA that codes for a gene. This can 'silence' that gene, ie prevent it being expressed. Methylation is important in regulating cell growth and differentiation.This process is very important, Coming into the details it involves the addition of a methyl group to the 5 position of cytosine pyrimidine ring or the number 6 nitrogen of the adenine purine ring (cytosine and adenine are two of the four bases of DNA). This modification can be inherited through cell division.SO as said above Dna methylation is nothing but
addition of a methyl group to the 5 position of the cytosine pyrimidine ring or the number 6 nitrogen of the adenine purine ring.DNA methylation is a crucial part of normal organismal development and cellular differentiation in higher organisms.In addition, DNA methylation suppresses the expression of viral genes and other deleterious elements that have been incorporated into the genome of the host over time.For the past years it has been proved and discovered that long-term memory storage in humans may be regulated by DNA methylation.

GENETIC FINGERPRINTING

Genetic or DNA fingerprinting is the term applied to a range of techniques that are used to show similarities and dissimilarities between the DNA present in different individuals.
Genetic fingerprinting can also be termed as DNA PROFILING.This is a technique especially employed by forensic scientists to assist in the identification of individuals on the basis of their respective DNA profiles.Although 99.9% of human DNA sequences are the same in every person, enough of the DNA is different to distinguish one individual from another.The process begins with a sample of an individual's DNA, Samples obtained from blood relatives (biological relative) can provide an indication of an individual's profile, as could human remains which had been previously profiled.A reference sample is then analyzed to create the individual's DNA profile using one of a number of techniques, discussed below. The DNA profile is then compared against another sample to determine whether there is a genetic match.

GENETICS

Genetics is the branch of biology that studies heredity and variation in organisms.To be more precise it is the science of genes,heredity,and variation in living organisms.Genes correspond to regions within DNA, a molecule composed of a chain of four different types of nucleotides, the sequence of these nucleotides is the genetic information organisms inherit.Although genetics plays a large role in the appearance and behavior of organisms, it is the combination of genetics with what an organism experiences that determines the ultimate outcome.A change to the DNA in a gene can change a protein's amino acids, changing its shape and function: this can have a dramatic effect in the cell and on the organism as a whole.Genetics is one subject which one has to definitely explore in the lifetime.

STEM CELLS

Stem cells are a class of undifferentiated cells that are able to differentiate into specialized cell types.They are the cells found in all multi cellular organisms. They are characterized by the ability to renew themselves through mitotic cell division.At present research in the stem cells is considered to be the toughest and greatest.Because Stem cells can now be grown and transformed into specialized cells with characteristics consistent with cells of various tissues such as

muscles or nerves.There are many ways in which human stem cells can be used in research.They can be used to test new drugs.Perhaps the most important potential application of human stem cells is the generation of cells and tissues that could be used for cell based therapies.Today, donated organs and tissues are often used to replace ailing or destroyed tissue, but the need for transplantable tissues and organs far outweighs the available supply. Stem cells, directed to differentiate into specific cell types, offer the possibility of a renewable source of replacement cells and tissues to treat diseases including Alzheimer's diseases and so many other diseases.

GENES

A gene can be defined as a region of DNA that controls a hereditary characteristic. It usually corresponds to a sequence used in the production of a specific protein or RNA.Genes undergo mutation when their DNA sequence changes.A gene is a basic unit in inheritance. Every gene consists of a linear sequence of bases in a nucleic acid molecule.Genes are specified by the sequence of bases in DNA in prokaryotic,archael,and eukaryotic cells,and in DNA or RNA.When proteins are manufactured, the gene is first copied into RNA as an intermediate product

In other cases, the RNA molecules are the actual functional products.The total complement of genes in an organism or cell is known as its genome which may be stored on one or more chromosomes. The region of the chromosome at which a particular gene is located is called its locus.The genetic code is the set of rules by which a gene is translated into a functional protein. Each gene consists of a specific sequence of nucleotides encoded in DNA.The vast majority of living organisms encode their genes in long strands of DNA.

CHROMOSOME

A chromosome is a threadlike linear strand of DNA and associated proteins in the nucleus of eukaryotic cells that carries the genes and functions in the transmission of hereditary information.In bacteria it is a circular strand of DNA in bacteria that contains the hereditary information necessary for cell life.In other words it is an organized structure of DNA and protein that is found in cells.It is a single piece of coiled DNA containing many genes,and other materials like regulatory elements,etc.. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions. Chromosomes are the essential unit for cellular division and must be replicated, divided, and passed successfully to their daughter cells so as to ensure the genetic diversity and survival of their progeny.Chromosomal recombination plays a vital role in genetic diversity.For most of the life of the cell, chromosomes are too elongated and tenuous to be seen under a microscope.