Science

Building blocks of DNA essential for LIFE 'may have formed in interstellar clouds'


The building blocks of DNA, and therefore life, may have come from the heart of interstellar gas cloud. 

A simulation ran inside an ultra-cold vacuum at Japan‘s Hokkaido University found nucleosomes can be created in space. 

These compounds form one of three parts of a nucleotide — a single piece of DNA —and could help shed light on how life evolved on Earth. 

Previous theories suggest a space rock travelled to Earth and brought with it the base materials for life, and from there the vast array of nature we see today evolved.

More complex compounds were also found, including amino acids, which go on to form proteins.  

Scroll down for video   

Japanese researchers analysed the simulated environment in an ultra-high vacuum reaction chamber (pictured). A gaseous mixture of water, carbon monoxide, ammonia, and methanol was fed into a material designed to mimic cosmic dust at -263°C

Japanese researchers analysed the simulated environment in an ultra-high vacuum reaction chamber (pictured). A gaseous mixture of water, carbon monoxide, ammonia, and methanol was fed into a material designed to mimic cosmic dust at -263°C

‘Our findings suggest that the processes we reproduced could lead to the formation of the molecular precursors of life,’ says Yasuhiro Oba, of Hokkaido University’s Institute of Low Temperature Science.

‘The results could improve our understanding of the early stages of chemical evolution in space.’ 

Basic organic molecules have previously been found in various comets, asteroids and gas clouds. 

And some scientists have made links from this to the origins of life on our planet around four billion years ago. 

DNA and RNA are integral to all forms of life, from humans to bacteria and they are a jigsaw of three separate pieces joined together — a phosphate group, a sugar and a nucleosome. 

RNA is lesser known than DNA but is extremely similar, but does not have the iconic double-helix structure. 

Its main role is to help DNA be read and interpreted so the information stored in it can be used by the body.  

The sugar can change and have extra oxygen attached, if it is lacking an oxygen at the second carbon atom, it is said to be deoxygenated and therefore creates DNA. 

If oxygen is found bonded to this specific atom, it creates RNA. 

The simple change to the singular atom alters the entire structure of the genetic material but the nucleosome is integral to the whole thing.  

Previous studies have imitated the conditions in interstellar molecular clouds and found sugar and phosphate, but not nucleobases.

This latest study, published in Nature Communications, changes this. 

‘This result could be key to unravelling fundamental questions for humankind, such as what organic compounds existed during the formation of the solar system and how they contributed to the birth of life on Earth’ says Oba.

Japanese researchers joined together to analyse the simulated environment in an ultra-high vacuum reaction chamber. 

Compounds for life form one of three parts of a nucleotide — a single piece of DNA —and could help shed light on how life evolved on Earth. Previous theories suggest a space rock travelled to Earth and brought with it the base materials for life, and from there the vast array of nature we see today evolved (stock)

Compounds for life form one of three parts of a nucleotide — a single piece of DNA —and could help shed light on how life evolved on Earth. Previous theories suggest a space rock travelled to Earth and brought with it the base materials for life, and from there the vast array of nature we see today evolved (stock)

A gaseous mixture of water, carbon monoxide, ammonia, and methanol was fed into a material designed to mimic cosmic dust at -263°C. 

At almost absolute zero, this was essential for modelling how molecules and compounds interact in the frigid abyss of space.  

Two deuterium lamps, an isotope of hydrogen, were attached to the vacuum chamber and supplied ultraviolet light to kickstart the reactions.   

An icy film was created inside the ultra-cold chamber bereft of oxygen and analysis of what this was made of revealed the nucleosomes.  

Cytosine, thymine, adenine were all found in the material, which are present in conventional DNA.

Lesser known compounds, such as uracil, xanthine, and hypoxanthine wer also present. 

WHAT IS THE DIFFERENCE BETWEEN DNA AND RNA?

DNA – deoxyribonucleic acid – is widely known as the molecule found in the nucleus of all our cells that contains genetic information.

It is shaped like a double-helix and made of small sections called nucleotides. 

Each nucleotide contains a nucleobase, a sugar, and a phosphate group.

The sugar component in this particular molecule is called deoxyribose and makes up the D in DNA.

This is a cyclic carbon-based chemical with five carbon atoms arranged as a pentagon.

At the second carbon atom there is an attached singular hydrogen atom in deoxyribose.

This can also have an additional oxygen attached as well. 

In this case, the oxygenated chemical then forms what is simply known as ribose – the R in RNA. 

The deoxy prefix literally means without oxygen.

Shape of RNA and DNA

RIbose can do almost everything deoxyribose can and also codes for genetic information in some cells and organisms.  

When the oxygen is present it drastically alters how the chemicals bonds and sits alongside other molecules. 

When oxygen is present – in RNA – it can take a variety of shapes. 

When oxygen is not present in this specific location – in DNA – the molecule forms as the iconic double helix. 

Uses of RNA 

DNA is often broken down into RNA and read by the cells in order to translate and transcribe the genetic code in order to make proteins and other molecules essential for life. 

RNA uses three of the same base pairs as DNA: Cytosine, Guanine, Adenine.

The othe base pair, Thymine, is swapped out in RNA for Uracil. 

RNA is also often found in simpler organisms, such as bacteria. 

It is often also a virus, with Hepatitis, flu and HIV all forms of RNA. 

Mitochondrial RNA 

All animal cells use DNA, with one notable exception: the mitochondria.

Mitochondrian are the powerhouses of the cell and turn glucose into pyruvate and then into Adenosine triphosphate (ATP) via the Krebs cycle. 

This process is all done in this one organelle in the cells and ATP is the universal form of energy and used throughout every aerobic organism. 

In the mitochondria there is a small strand of RNA which is unique in the animal kingdom. 

It is passed down from the mother exclusively (the father’s lives in the sperm but is dissolved during fertilisation) and allows humans to trace their maternal lineage back throughout time.  

 



READ SOURCE

Leave a Reply

This website uses cookies. By continuing to use this site, you accept our use of cookies.