Date: Around 1993
What is the purpose of the mitochondria which float around inside
of a cell?
Mitochondria produce energy for the cell in the form of a
compound called ATP. By a process known as "oxidative phosphorylation",
mitochondria take energy derived from nutrients that the organism provides to
its cells through the bloodstream, and oxygen provided to the cell, and
convert the energy into ATP. ATP has three phosphate chemical groups linked
to it by special bonds. When one of these bonds is broken, converting 3
phosphates (ATP) to 2 (ADP), energy is released that the cell can then use for
other purposes, such as contraction (in the case of a muscle) or other things.
Mitochondria have received a lot of attention recently because
they have their own DNA which inherited only from the mother. by comparing
mitochondria DNA from people all over the world, geneticists can estimate how
long homo sapiens has been around, and the surprising results were: only a
few hundred thousand years and it looks like we all descended from one mother!
This is called the Eve theory and is VERY controversial. Some scientist
believe that mitochondria were once independent life, and that a symbiotic
relationship arose between them and early, primitive single-cell plants and
animals. That would help explain why they have their own DNA.
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Update: June 2012