How many atoms in dna

how many atoms in dna

how many atoms make up a dna strand?

Jul 20, †Ј DNA only has 5 different atoms, carbon, hydrogen, oxygen, nitrogen and phosphorous. according to one estimation there are about billion atoms in each DNA. This page, looking at the structure of DNA, is the first in a sequence of pages leading on to how DNA replicates (makes copies of) itself, and then to how information stored in DNA is used to make protein molecules. This material is aimed at 16 - 18 year old chemistry students. If you are interested.

There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page. A nucleotide is made up of a pentose sugar called deoxy ribose, a nitrogenous base and a phosphate group.

To get an exact figure, you will have to take into account, the different sizes of different atoms, the distance between the atoms, the pattern of their arrangement and all of that. Trending News. Liberty sues Jerry Falwell Jr. Pentagon confirms leaked UFO photos, video are real.

This is the trap question in a salary negotiation. Republican foreign policy isn't what it used to be. Rise in depression noted, but suicides may have decreased. Looking for incentive to move? Racial injustice on 'Grey's Anatomy' angers viewers. Education Dept. Answer Save. Chandana Lv 4. A DNA strand is very very long Let's break up the question a bit: How bigger is a single how many atoms in dna of DNA than an atom? A single unit of DNA is called a nucleotide.

How to unprotect a password protected word document, the average DNA strand in humans contains about million of these nucleotides. So, the total number of atoms in the DNA strand would be million x number of atoms in each nucleotide.

This will give you a very rough idea of how big DNA is compared to an how many atoms in dna. I hope this answer helped! How do you think about the answers? You can sign in to vote the answer. DNA only has 5 different atoms, carbon, hydrogen, oxygen, nitrogen and phosphorous.

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Apr 06, †Ј Multiply that by 6 billion nucleotides and you get billion atoms. Of course, thatТs just an estimate since human DNA isnТt composed of only СTТ nucleotides, and I think some of them can have more than one phosphate group (not sure). Nov 14, †Ј Surprisingly, the rest of the DNA is mostly useless, and although there may be genes in there that encode interesting elements, research will focus first on uncovering the secrets of that small Author: Ella Kelly. DNA is composed of five different atoms (in various combinations): * C Ч Carbon * H Ч Hydrogen * O Ч Oxygen * P Ч Phosphorus * N Ч Nitrogen Please enable Javascript and refresh the page to continue.

Alongside proteins , lipids and complex carbohydrates polysaccharides , nucleic acids are one of the four major types of macromolecules that are essential for all known forms of life.

The two DNA strands are known as polynucleotides as they are composed of simpler monomeric units called nucleotides. The nucleotides are joined to one another in a chain by covalent bonds known as the phospho-diester linkage between the sugar of one nucleotide and the phosphate of the next, resulting in an alternating sugar-phosphate backbone.

The nitrogenous bases of the two separate polynucleotide strands are bound together, according to base pairing rules A with T and C with G , with hydrogen bonds to make double-stranded DNA. The complementary nitrogenous bases are divided into two groups, pyrimidines and purines. In DNA, the pyrimidines are thymine and cytosine; the purines are adenine and guanine. Both strands of double-stranded DNA store the same biological information.

This information is replicated as and when the two strands separate. The two strands of DNA run in opposite directions to each other and are thus antiparallel. Attached to each sugar is one of four types of nucleobases informally, bases. It is the sequence of these four nucleobases along the backbone that encodes genetic information.

Within eukaryotic cells, DNA is organized into long structures called chromosomes. Before typical cell division , these chromosomes are duplicated in the process of DNA replication , providing a complete set of chromosomes for each daughter cell. Within eukaryotic chromosomes, chromatin proteins, such as histones , compact and organize DNA.

These compacting structures guide the interactions between DNA and other proteins, helping control which parts of the DNA are transcribed. DNA is a long polymer made from repeating units called nucleotides , each of which is usually symbolized by a single letter: either A, T, C, or G. The structure of DNA is dynamic along its length, being capable of coiling into tight loops and other shapes. The pair of chains have a radius of 10 angstroms 1. Chromosome 1 is the largest human chromosome with approximately million base pairs , and would be 85 mm long if straightened.

DNA does not usually exist as a single strand, but instead as a pair of strands that are held tightly together. The nucleotide contains both a segment of the backbone of the molecule which holds the chain together and a nucleobase which interacts with the other DNA strand in the helix. A nucleobase linked to a sugar is called a nucleoside , and a base linked to a sugar and to one or more phosphate groups is called a nucleotide.

A biopolymer comprising multiple linked nucleotides as in DNA is called a polynucleotide. The backbone of the DNA strand is made from alternating phosphate and sugar groups. The sugars are joined together by phosphate groups that form phosphodiester bonds between the third and fifth carbon atoms of adjacent sugar rings. In a nucleic acid double helix , the direction of the nucleotides in one strand is opposite to their direction in the other strand: the strands are antiparallel.

The DNA double helix is stabilized primarily by two forces: hydrogen bonds between nucleotides and base-stacking interactions among aromatic nucleobases. These four bases are attached to the sugar-phosphate to form the complete nucleotide, as shown for adenosine monophosphate. Adenine pairs with thymine and guanine pairs with cytosine, forming A-T and G-C base pairs.

The nucleobases are classified into two types: the purines , A and G, which are fused five- and six-membered heterocyclic compounds , and the pyrimidines , the six-membered rings C and T.

In addition to RNA and DNA, many artificial nucleic acid analogues have been created to study the properties of nucleic acids, or for use in biotechnology.

Modified bases occur in DNA. The first of these recognised was 5-methylcytosine , which was found in the genome of Mycobacterium tuberculosis in This enzyme system acts at least in part as a molecular immune system protecting bacteria from infection by viruses.

A number of non canonical bases are known to occur in DNA. Twin helical strands form the DNA backbone. Another double helix may be found tracing the spaces, or grooves, between the strands. These voids are adjacent to the base pairs and may provide a binding site. As the strands are not symmetrically located with respect to each other, the grooves are unequally sized.

As a result, proteins such as transcription factors that can bind to specific sequences in double-stranded DNA usually make contact with the sides of the bases exposed in the major groove. In a DNA double helix, each type of nucleobase on one strand bonds with just one type of nucleobase on the other strand. This is called complementary base pairing. Purines form hydrogen bonds to pyrimidines, with adenine bonding only to thymine in two hydrogen bonds, and cytosine bonding only to guanine in three hydrogen bonds.

This arrangement of two nucleotides binding together across the double helix is called a Watson-Crick base pair. A Hoogsteen base pair is a rare variation of base-pairing. The two strands of DNA in a double helix can thus be pulled apart like a zipper, either by a mechanical force or high temperature. This reversible and specific interaction between complementary base pairs is critical for all the functions of DNA in organisms.

As noted above, most DNA molecules are actually two polymer strands, bound together in a helical fashion by noncovalent bonds; this double-stranded dsDNA structure is maintained largely by the intrastrand base stacking interactions, which are strongest for G,C stacks. As a result, it is both the percentage of GC base pairs and the overall length of a DNA double helix that determines the strength of the association between the two strands of DNA.

Long DNA helices with a high GC-content have stronger-interacting strands, while short helices with high AT content have weaker-interacting strands. In the laboratory, the strength of this interaction can be measured by finding the temperature necessary to break half of the hydrogen bonds, their melting temperature also called T m value. When all the base pairs in a DNA double helix melt, the strands separate and exist in solution as two entirely independent molecules.

These single-stranded DNA molecules have no single common shape, but some conformations are more stable than others. A DNA sequence is called a "sense" sequence if it is the same as that of a messenger RNA copy that is translated into protein. Both sense and antisense sequences can exist on different parts of the same strand of DNA i.

In both prokaryotes and eukaryotes, antisense RNA sequences are produced, but the functions of these RNAs are not entirely clear. A few DNA sequences in prokaryotes and eukaryotes, and more in plasmids and viruses , blur the distinction between sense and antisense strands by having overlapping genes.

In bacteria , this overlap may be involved in the regulation of gene transcription, [35] while in viruses, overlapping genes increase the amount of information that can be encoded within the small viral genome. With DNA in its "relaxed" state, a strand usually circles the axis of the double helix once every If they are twisted in the opposite direction, this is negative supercoiling, and the bases come apart more easily.

In nature, most DNA has slight negative supercoiling that is introduced by enzymes called topoisomerases. Although the B-DNA form is most common under the conditions found in cells, [44] it is not a well-defined conformation but a family of related DNA conformations [45] that occur at the high hydration levels present in cells.

Their corresponding X-ray diffraction and scattering patterns are characteristic of molecular paracrystals with a significant degree of disorder. Here, the strands turn about the helical axis in a left-handed spiral, the opposite of the more common B form. For many years, exobiologists have proposed the existence of a shadow biosphere , a postulated microbial biosphere of Earth that uses radically different biochemical and molecular processes than currently known life.

One of the proposals was the existence of lifeforms that use arsenic instead of phosphorus in DNA. A report in of the possibility in the bacterium GFAJ-1 , was announced, [52] [53] though the research was disputed, [53] [54] and evidence suggests the bacterium actively prevents the incorporation of arsenic into the DNA backbone and other biomolecules.

At the ends of the linear chromosomes are specialized regions of DNA called telomeres. These guanine-rich sequences may stabilize chromosome ends by forming structures of stacked sets of four-base units, rather than the usual base pairs found in other DNA molecules. Here, four guanine bases, known as a guanine tetrad , form a flat plate. These flat four-base units then stack on top of each other to form a stable G-quadruplex structure.

In addition to these stacked structures, telomeres also form large loop structures called telomere loops, or T-loops. Here, the single-stranded DNA curls around in a long circle stabilized by telomere-binding proteins.

This triple-stranded structure is called a displacement loop or D-loop. In DNA, fraying occurs when non-complementary regions exist at the end of an otherwise complementary double-strand of DNA.

However, branched DNA can occur if a third strand of DNA is introduced and contains adjoining regions able to hybridize with the frayed regions of the pre-existing double-strand. Although the simplest example of branched DNA involves only three strands of DNA, complexes involving additional strands and multiple branches are also possible.

Several artificial nucleobases have been synthesized, and successfully incorporated in the eight-base DNA analogue named Hachimoji DNA. Their existence could be seen as an indication that there is nothing special about the four natural nucleobases that evolved on Earth.

For this purpose it has to fold into a structure. It has been shown that to allow to create all possible structures at least four bases are required for the corresponding RNA , [66] while a higher number is also possible but this would be against the natural Principle of least effort. The expression of genes is influenced by how the DNA is packaged in chromosomes, in a structure called chromatin. Base modifications can be involved in packaging, with regions that have low or no gene expression usually containing high levels of methylation of cytosine bases.

DNA packaging and its influence on gene expression can also occur by covalent modifications of the histone protein core around which DNA is wrapped in the chromatin structure or else by remodeling carried out by chromatin remodeling complexes see Chromatin remodeling. There is, further, crosstalk between DNA methylation and histone modification, so they can coordinately affect chromatin and gene expression. For one example, cytosine methylation produces 5-methylcytosine , which is important for X-inactivation of chromosomes.

Mutagens include oxidizing agents , alkylating agents and also high-energy electromagnetic radiation such as ultraviolet light and X-rays. The type of DNA damage produced depends on the type of mutagen. For example, UV light can damage DNA by producing thymine dimers , which are cross-links between pyrimidine bases.

Because of inherent limits in the DNA repair mechanisms, if humans lived long enough, they would all eventually develop cancer. Although most of these damages are repaired, in any cell some DNA damage may remain despite the action of repair processes. These remaining DNA damages accumulate with age in mammalian postmitotic tissues. This accumulation appears to be an important underlying cause of aging. Many mutagens fit into the space between two adjacent base pairs, this is called intercalation.

Most intercalators are aromatic and planar molecules; examples include ethidium bromide , acridines , daunomycin , and doxorubicin. For an intercalator to fit between base pairs, the bases must separate, distorting the DNA strands by unwinding of the double helix.

This inhibits both transcription and DNA replication, causing toxicity and mutations. DNA usually occurs as linear chromosomes in eukaryotes , and circular chromosomes in prokaryotes. The set of chromosomes in a cell makes up its genome ; the human genome has approximately 3 billion base pairs of DNA arranged into 46 chromosomes.

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