This article is a FAQ section for deoxyribose nucleic acid- DNA, we will answer some of the commest question related to it and try to explain it.
- What is DNA?
- What is DNA stand for?
- What is the exact definition of DNA?
- What is DNA made up of?
- What is the function of DNA?
- What is the structure of DNA?
- What is DNA replication?
- What is DNA transcription
- What is DNA translation?
- What is DNA recombination?
- What is DNA fingerprinting?
- What is DNA polymerase?
- What is a DNA mutation?
- Where is DNA found in a prokaryotic cell?
- Where is DNA found in eukaryotic cells?
What is DNA?
The DNA is a nucleic acid- present in a living cell of all organisms on earth, made up of sugar, phosphate and bases.
Starting from Single-cell prokaryotes to multicellular organism the deoxyribose nucleic acid is present in all organism, either in a cell, in the cytoplasm or in both.
Different structural and functional proteins such as cell wall protein, glycoproteins, phosphoproteins, chaperons, receptors, antibodies, haemoglobin and other protein molecules are formed from the DNA.
Thus, if any alteration occurs in a deoxyribose nucleic acid it creates a major problem for us. This is the reason, the deoxyribose nucleic acid is important for us, in fact for all the living organisms.
What is DNA stand for?
The DNA stands for deoxyribose nucleic acid.
What is DNA made up of?
The DNA-deoxyribose nucleic acid is made up of three components- nitrogenous bases, deoxy sugar and phosphate.
The diagram of the deoxyribose nucleic acid is given into the figure below,
Deoxyribose nucleic acid diagram:
The diagram of the deoxyribose nucleic acid (DNA) is shown that the backbone of the DNA is made up of the triphosphate which is joined by the deoxy sugar along with the nitrogenous base.
The entire unit is called a nucleotide which is joined adjacent nucleotide with phosphodiester bond.
From the deoxyribose nucleic acid diagram, we can say that the DNA is a polynucleotide chain.
What is the exact definition of DNA?
DNA- a type of nucleic acid is a biomolecule made up of polynucleotide chain functions to store and transfer the genetic information.
What is the function of DNA?
The main function of the DNA is to store and transfer information from one cell to another and from one generation to another.
This is important to discuss,
The DNA is a storage unit just like our computer. It stores crucial information for the survival of life. A triplet codon from the four bases- adenine, thymine, cytosine and guanine forms a single amino acid which ultimately forms a protein.
Even though some DNA sequences can not form protein, still it maintains the expression of a gene.
So the DNA performs a function to form protein and to control the expression of it.
By doing replication, transcription and translation it performs all these functions.
By doing the replication, the DNA becomes doubled and inherited to the daughter cells.
By doing the transcription, the mRNA for a particular gene formed and by doing transcription, a chain of amino acid is constructed from the mRNA.
Interestingly, the entire process is completed in the nucleus as well as cytoplasm. The replication and transcription occur in the nucleus and the translation occurs in the cytoplasm.
What is the structure of DNA?
The DNA is a spiral helical structure in which two different single-strands of DNA bound with each other with hydrogen bonds in a spiral manner.
As we discussed above, deoxyribose nucleic acid is made up of the sugar, phosphate and nitrogenous bases called a nucleotide.
A nucleotide binds with another adjacent nucleotide with phosphodiester bond and to the nucleotide of the opposite strand with hydrogen bonds.
A double-helical structure of DNA creates one major groove and one minor groove, a minor groove protects it from the enzymatic cleavage.
Structurally, the DNA is B-form right-handed in symmetry.
What is DNA replication?
DNA replication is an enzymatic process in which the DNA molecule becomes doubled or copied.
Broadly, in the DNA replication, the DNA polymerase adds nucleotides to the growing DNA strand using the 3’ PH end of the primer.
Read our article on replication: General process of DNA replication.
What is DNA transcription?
The DNA transcription is a process in which the function mRNA (messenger RNA) is formed from the DNA and this mRNA has the information to form a protein.
Transcription occurs in the nucleus of a cell but once the mRNA is formed it migrates to the cytoplasm of the cell for doing a translation.
What is a translation?
The translation is a process in which the polypeptide chain of amino acid is formed from the mRNA in the cytoplasm at the ribosome.
What is DNA recombination?
The process of exchanging genetic material between two DNA strand is called a process of DNA recombination. By doing the recombination, different genetic variations in nature are created.
What is DNA fingerprinting?
DNA fingerprinting is a process of profiling the DNA of an individual for the purpose of identifying individuals based on their DNA profile.
Just like the fingerprint, the DNA profile varies among individuals. Some of the repeated sequence regions of our genome called STR a VNTR are used to do DNA fingerprinting.
Different individuals have different STR and VNTR profiles based on that it is used for identification of persons, criminal verification and parental verification.
Related article: DNA fingerprinting.
What is DNA polymerase?
The DNA polymerase is an enzyme that catalyses the reaction for duplicating DNA called DNA replication.
Using the 3’ OH end of the primer, the DNA polymerase inserts nucleotides to the growing DNA strand and synthesise new complementary DNA strand.
Taq DNA polymerase is one of the popular polymerase used during the in vitro replication called a polymerase chain reaction.
Related article: DNA polymerase.
What is a DNA mutation?
Any alteration in the DNA sequence, gene or gene expression which influence the phenotype is called a DNA mutation.
Insertion, deletion, duplication and translocation are some of the common DNA mutations occurs in a genome due to various reasons.
Single nucleotide polymorphism is one of the common DNA mutations occurs in a genome in which a single base is inserted or deletion from the DNA sequence.
These single base variations are associated with some complex- polygenetic disorders.
Where is DNA found in a prokaryotic cell?
In a prokaryotic cell-like bacterial the DNA is found in nucleus as well cytoplasm. The bacterial chromosome contains all the genetic information in a nucleus and circular plasmid DNA present in a cytoplasm contains genes for antibiotic resistance and for genes to survive.
Interestingly, the plasmid DNA present in a bacterial is used for the gene transfer experiments in which our gene of interest can be artificially inserted in a genome.
Where is DNA found in a Eukaryotic cell?
In eukaryotic cells also, the DNA is present in the cytoplasm as well in a nucleus.
The entire genomic DNA is present in a nucleus of a cell and arranged on chromosomes.
While some of the organelles such as mitochondria and chloroplast also contain some of the DNA.
Deoxyribose nucleic acid- DNA was discovered in the year 1953 by Watson and Crick. Scientists are now trying to insert DNA artificially into the genome. This can be helpful in preventing genetic disorders.
DNA is a mysterious, complicated and complex biomolecule. Scientists have solved many mysteries of life by DNA analysis.
DNA profiling and DNA fingerprinting like techniques are used for solving criminal cases and parental verification.