Why organisms reproduce?

Mohit Pandey · 12-22-2007

Quote:

Originally Posted by freeztar

A very good question Mohit!

The simplest answer, I suppose, would be instinct.

One must also think about "the chicken and the egg" and which came first. The organism must have come about from reproduction of another organism (unless we're talking about the first organism). So it makes sense that the organism continues with tradition because otherwise it would never have come to be.

learnin to learn! My previous post was a reply of this post.

learnin to learn · 12-22-2007

ok thank you Mohit

taijishengnv · 12-22-2007

a new news for it
An efficient way to make small molecules by repeatedly using just one coupling reaction to clip together pre-prepared chemical fragments is going commercial.

Martin Burke and colleagues from the University of Illinois, US, have demonstrated that by exclusively using Suzuki-Miyaura coupling (a popular reaction for making carbon-carbon bonds) they can make complex natural products from customised building blocks, such as double bonds and aromatic rings[1].

A range of suitable building blocks will be commercially available worldwide within eight months, ready to be bought off-the-shelf, Burke says, thanks to an agreement with a large chemical company. And the technique is already being used in the pharmaceutical industry to quickly make new collections of small molecules for drug screening.

'The impact of this, not the least of which will be making the power of small molecule synthesis available to the non-expert, could be extraordinary,' Burke told Chemistry World. 'Ultimately, we envision a collection of about 100 building blocks, and the chemistry is so simple that we feel very optimistic about automating the process.'

Burke's technique has parallels with the way small proteins are made, where amino acid building blocks are slotted together by repeated, and automated, use of peptide coupling. Just about any scientist can make or order a peptide today, but organic synthesis - even of small molecules - remains accessible only to highly-trained chemists.

All change

Burke hopes to change that with a series of haloboronic acid building blocks, of which he has published 9 prototypes so far. These reagents can be linked together repeatedly with Suzuki coupling because both the necessary coupling partners are contained in one bifunctional molecule - a halide at one end, a building block in the middle, and a boronic acid at the other end.

But such a reaction would quickly run out of control, with building blocks linking together haphazardly in any order, were it not for a key protecting group which shuts off the reactivity of the boron end, and, crucially, can also be removed without harsh reaction conditions that would affect the growing molecule. Earlier this year, Burke's team showed that the cheap and non-toxic MIDA (N-methyliminodiacetic acid) ligand masked boron's reactivity and was stable to anhydrous bases, yet could be removed at room temperature by any weak aqueous base - including sodium bicarbonate - when required [2].

This makes it possible to couple a protected fragment at its halide end only, then remove the MIDA ligand and expose the boronic acid, ready to link to another fragment and repeat.