Genome complexity: Protecting mitochondrial DNA (Introduction)

by David Turell , Monday, May 01, 2017, 01:21 (2546 days ago) @ David Turell

If mitochondrial DNA is damaged it can be repaired quickly:

https://www.sciencedaily.com/releases/2017/04/170428145549.htm

"The five-year study led by scientists at the University of Sheffield, published in Science Advances, reveals how the enzyme TDP1 -- which is already known to have a role in repairing damaged DNA in the cell's nucleus -- is also responsible for repairing damage to mitochondrial DNA (mtDNA).
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"Mitochondria are the powerhouses of cells, they generate the energy required for all cellular activity and have their own DNA -- the genetic material which they rely upon to produce important proteins for their function.

"During the process of energy production and making proteins, a large amount of rogue reactive oxygen species are produced which constantly attack the DNA in the mitochondria. These attacks break their DNA, however the new findings show mitochondria have their very own repair toolkits which are constantly active to maintain their own DNA integrity.

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"Each mitochondria repair toolkit has unique components -- enzymes -- which can cut, hammer and seal the breaks. The presence of these enzymes is important for energy production.

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"The team further identified a mechanism through which mtDNA can be damaged and then fixed, via a protein called TOP1, which is responsible for untangling coils of mtDNA. When the long strands become tangled, TOP1 breaks and quickly repairs the strands to unravel the knots. If free radicals are also attacking the mitochondrial DNA, then TOP1 proteins can become trapped on the mitochondrial DNA strands, making repair even more difficult."

Comment: Since mitchondria supply the energy for cells to keep working in production, once mitochondria were part of the cell this repair mechanism had to be in place, from the beginning. That is not a problem. Mitochondria were originally independent organisms according to accepted theory. They had the repair mechanism on board. But carry the thought further. Any independent single-celled animal had to have repair mechanisms from the very first time DNA was formed, or the cells would not have survived. The lesson is the only way life started in cellular form, it had to have a complete set of functions: energy, production of product, disposal of byproduct garbage, the ability to reproduce by splitting, and constant accurate repair. And each of these processes use giant molecules called enzymes, which are specific for each reaction to make it happen and quickly. Bacteria reproduce themselves about every 20 minutes. Since they never die, as sexual animals do, today's bacteria represent direct vestige's of original life. Which had to appear all at once!! Only a designing mind could create this: God