Question #dd711
1 Answer
Mother Nature needs no reason...
Explanation:
I don't think you will ever be able to find a satisfactory answer to that question.
Don't forget, life started (OK, allegedly!) due to the cooperation of macromolecules...
Over millions, if not billions of years, with gazillions of mutations (of which by far most ended in tears) it evolved into life as we know it now.
Though life is incredibly diverse in its myriad of expressions, the core systems are virtually unchanged: all known mechanisms use the same 20 proteinogenic amino acids for instance, indeed the Genetic code is deemed to be " universal ", and though Mother Nature keeps on experimenting with mutations, as mentioned, most of them end in tears, often resulting in the new organism not even making it to birth...
More specifically, regarding the enzyme that forms GDP (Succinate—CoA ligase), don't forget that the Citrate Cycle takes place in the Mitochondrion.
It is assumed that in eons past Mitochondria were bacteria in their own right, with one tremendous evolutionary advantage: oxidative phosphorylation . It is assumed that other cells started to live in symbiosis with them: Enveloping them, thereby protecting them and giving them access to nutrients, in return for the added advantage of OP.
Over time, and due to the "right" mutations, mitochondria eventually became nothing more than just another cell organelle.
Nevertheless, Mitochondria, due to their origins as independent organisms , retain their own DNA. The major complexes in the Electron Transport Chain are partly coded for by Nuclear, partly by mitochondrial DNA.....
Mitochondrial DNA is highly conserved: mutations in this mDNA do not fare very well: most of them are lethal. This is partly caused by the fact that there is no cross-over with other chromosomes:
For starters, mDNA is situated in the Mitochodrion itself, not the Nucleus, so there is a physical barrier.
Secondly: You inherit mitochondria from your Mother by means of presence in her Ovum, the father plays no part in this respect whatsoever.
Summarising: GDP was probably used by Mitochiondria in the distant past, and that is left unchanged over time. If it isn't broken, don't fix it, and apparently, if Mother Nature tries, it is lethal...
IDP (Inositol) is also used, by the way.....
