Conceptie, in seks, is een kernfusiereactie.
Twee cellen komen samen, en versmelten (fuseren) in hun kern.
Wat gepaard gaat met atomaire kernkrachten in de celkern.
Celdeling is, letterlijk, een kernsplitsingsreactie.
De cel ‘vervloeit’, de moleculen ‘verdampen’, en de atomen ‘lossen op’.
Daarin vallen de atomen uiteen; atoombindingen ontbinden.
Het gaat daar om kernkrachten; net als in kerncentrales.
In celdeling valt de DNA uiteen; over haar hele lengte (2 meter).
DNA is een molecule opgebouwd door het mantel-eiwit in de celkern.
DNA omvar enorme hoeveelheden atoombindingen, in samenhang.
Maar in een celdeling worden AL die DNA kernbanden in EEN beweging ontbonden.
Hieronder zijn voorbeelden te vinden van ramingen van de lengte van DNA (2 meter per cel).
In de kern-splitsing worden de base-paren gesplitst (3.2 miljard)
Met, daarin, een schatting van het aantal atomen in een DNA ‘molecule’ (204 miljard).
Waarin in feite maar een beperkt aantal soorten atomen de structuurvormen bepalen
REKEN UIT HOEVEEL ENERGIE NODIG IS ON EEN DNA MOLECULE TE SPLITSEN…
How many base pairs does DNA contain?
3.2 billion: That’s how many base pairs—or sets of genetic “letters”—make up the human genome.
20,000: That’s the approximate number of genes in the human genome.
37: That’s the number of genes in our “other” genome—the mitochondrial genome
The haploid human genome has about 3.17 billion base pairs, and if completely unwound would have a length of about 6 feet (2 meters). Most cells are diploid and have two copies, for a total of 6.34 billion base pairs (12 feet / 4 meters).
This haploid DNA is distributed among 23 chromosomes*, ranging in length from 250 million base pairs to under 50 million base pairs. So the longest single molecule of DNA in the human body would be about 6 inches (16 cm) if unwound.
* For purposes of this discussion, only nuclear DNA is considered. The human mitochondrial DNA is disregarded.
|Chromosome||Length (mm)||Base pairs||Variations||Confirmed proteins||Putative proteins||Pseudogenes||miRNA||rRNA||snRNA||snoRNA||Misc ncRNA||Links||Centromere position (Mbp)||Cumulative (%)|
How many atoms does DNA contain?
DNA only has 5 different atoms, carbon, hydrogen, oxygen, nitrogen and phosphorous.
according to one estimation there are about 204 billion atoms in each DNA .
How Many Atoms to Encode the Human Genome?
We often hear about how the deoxyribonucleic acid (DNA) macro-molecule that contains the human genome has about 3 billion base pairs, but we rarely hear about the atoms. I was curious to know how many such a complex structure required…
Warning: Back of the envelope calculations.
Here we go:
3 billion base pairs equals 6 billion nucleotides.
The human genome uses 4 types of nucleotides:
- Adenine (A)
- Guanine (G)
- Cytosine (C)
- Thymine (T)
‘T’ is always associated with ‘A’, and ‘G’ with ‘C’.
Each of these nucleotides is composed of a nitrogen-containing base, a five-carbon sugar, and a phosphate group.
To simplify, we’ll only look at Thymine, which is pretty representative of the others in size.
Thymine’s base is a pyrimidine ring compound and it contains 15 atoms. Its pentose sugar has 15 atoms also (the 5-carbon sugar used for ribonucleic acid (RNA) is very similar, but it has an extra oxygen atom). The phosphate group contains 4 atoms.
Total for a thymine nucleotide: 34 atoms.
Multiply that by 6 billion nucleotides and you get 204 billion atoms.
Of course, that’s just an estimate since human DNA isn’t composed of only ‘T’ nucleotides, and I think some of them can have more than one phosphate group (not sure). But it should be in the right ballpark.
The enzymes of DNA polymerase can copy human DNA, shuffling hundreds of billions of atoms with great precision, including proofreading and sometimes error correction, in a very short amount of time (if you know the precise timing, please let me know).
Now that is nanoscale molecular manufacturing that works! If that’s not impressive, I don’t know what is.
A DNA strand is very very long……………
Let’s break up the question a bit:
How bigger is a single unit of DNA than an atom?
A single unit of DNA is called a nucleotide.
A nucleotide is made up of a pentose sugar called deoxy ribose, a nitrogenous base and a phosphate group.
Each molecule of deoxyribose has 5 carbon atoms + 10 hydrogen atoms + 4 oxygen atoms
= 19 atoms
There are four kinds of nitrogenous bases in DNA:
Adenine, thymine, guanine, cytosine
Adenine has 8 atoms in it
Guanine has 16 atoms
Thymine has 6 atoms
Cytosine has 7 atoms
Phosphate group has about 4 atoms.
So, each nucleotide may have
19 + 8 + 4 = 31 atoms
19+16+4 = 39 atoms
19+6+4= 29 atoms
19+7+4 = 30 atoms.
Now, the average DNA strand in humans contains about 440 million of these nucleotides.
So, the total number of atoms in the DNA strand would be
440 million x number of atoms in each nucleotide.
This will give you a very rough idea of how big DNA is compared to an atom.
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.
Length of a Human DNA Molecule
Your DNA is arranged as a coil of coils of coils of coils of coils! This allows the 3 billion base pairs in each cell to fit into a space just 6 microns across. If you stretched the DNA in one cell all the way out, it would be about 2m long and all the DNA in all your cells put together would be about twice the diameter of the Solar System.
You have about 10 trillion cells in your body, so if you stretched the DNA in all the cells out, end to end, they’d stretch over 744 million miles. The moon is only about 250,000 miles away, so all your DNA would stretch to the moon and back alomst 1500 times. The sun is 93,000,000 miles away, so your DNA would reach there and back about 4 times!
A common citation for the length of DNA in our bodies is that one cell of DNA contains about 5 – 6 feet (2 meters) of DNA per cell. Estimates place the number of cells in our body at about 100 trillion in total. Not all of those cells contain DNA (blood cells do not, for example) so we can lower that number to perhaps 50 – 70 trillion DNA containing cells.
Let’s take the lower estimate. 50 trillion x 6 ft = 300 trillion ft, or about 60 billion miles. Since the moon is 260,000 miles from us, then 60 billion / 260,000 = 218,000. In short, the DNA in one human body would stretch to the moon and back 109,000 times (at least).
The Physics Factbook™, Edited by Glenn Elert — Written by his students
|Mitchel, Campbell Reece. Biology Concept and Connections. California, 1997.||“At actual size, a human cell’s DNA totals about 3 meters in length.”||3.0 m|
|McGraw Hill Encyclopedia of Science and Technology. New York: McGraw Hill, 1997.||“If stretched out, would form very thin thread, about 6 feet (2 meters) long.”||2.0 m|
|Matthews, Harry R. DNA Structure Prerequisite Information. 1997.||“The length is (length of 1 bp)(number of bp per cell) which is (0.34 nm)(6 × 109)”||2.0 m|
|Leltninger, Albert L. Biochemistry. New York: Worth, 1975.||“Chromosome 13 contains a DNA molecule about 3.2 cm long.”||1.5 m|
|“Cell.” The World Book Encyclopedia. Chicago: Field Enterprises, 1996.||“On the average, a single human chromosome consists of DNA molecule that is about 2 inches long.”||2.3 m|