Susanna Pilny for redOrbit.com – Your Universe Online
Let’s get right down to it.
Mitochondria are intelligent, microscopic organisms that live inside the cells of all things. When present in high numbers, they allow their host to sense the Force. Jedi—
No wait, that’s midi-chlorians. Sorry.
Mitochondria are similar, though. The most common explanation you hear is that mitochondria are “cellular power plants,” which is true, but isn’t extremely scientific. To be more scientific, we’ll say: Mitochondria are microscopic components of almost every cell in your body, known as organelles. They take oxygen and sugar from the cell and, through a complicated series of steps that tend to cause nervous breakdowns in biochemistry students, create water, carbon dioxide, and energy in return—otherwise known as the Krebs Cycle and oxidative phosphorylation, or “Why didn’t I take anatomy instead?”
In humans, the energy made is contained in the form of ATP and GTP, which can be used to power more or less anything that needs an input of energy in the cell. (Hence the “powerhouse” explanation, or in midi-chlorians, the Force.)
Mitochondria are their own beast
But mitochondria go way beyond being just another bit of cell machinery, because scientists think they used to be their own organisms. The prevailing theory is that originally they lived as bacteria inside eukaryotic cells (the type of cells animals are made of). They received food from their hosts in exchange for energy from themselves—otherwise known as symbiosis. Over the years, the two cells became a single cell, and mitochondria became relegated to a sub-structure of eukaryotic cells.
[STORY: Mitochondrial ‘smart bomb’ could treat brain tumors]
Scientists think this because, unlike anything else in our cells, mitochondria have their own DNA completely separate from what we consider generally consider normal DNA. “Normal” DNA comes from both of our parents, forming double helices in our cells. Mitochondrial DNA comes only from one parent: the mother. In fact, all the mitochondrial DNA in the world can be traced back around 100,000 years to one woman, whom scientists like to call “Mitochondrial Eve”. This woman, out of the probable thousands of others alive at the time, produced the only unbroken chain of female heirs to survive to today. In every other case, somewhere between now and 100,000 years ago, the other lines died out or only males were left in the line—meaning their children wouldn’t inherit their female-passed DNA.
All this being said, it’s easy to see why mitochondrial disease can be so devastating—you can’t survive without energy. Beyond that, mitochondrial issues have been linked to many other diseases like Alzheimer’s, Parkinson’s, and some cancers as well as aging. But there is hope on the horizon, especially for women with mitochondrial diseases who are looking to have children: Researchers have created a way to substitute in mitochondrial DNA from other women into your own eggs. This means that the child will still have your “normal” DNA, but will just have different mitochondria.
—–
Follow redOrbit on Twitter, Facebook, Google+, Instagram and Pinterest.
Comments