Today was an amazing lecture by Dr. David Lee about mitochondria and its role in aging. Dr. Lee started with an overview of what mitochondria is and what it does. You may have heard that the origin of mitochondria is bacteria that was engulfed by the cell early in the course of evolution. There are several things that back this «endosymbioic» theory:
- Mitochondria self-replicates
- It has two membranes
- It has its own independent DNA
- The ribosomes are similar to those of bacteria
- The sizes are very alike
- Mitochondrial DNA shares similar to bacterial structural motifs
- The inner mitochondria membrane has a more bacterial-like lipid composition
Mitochondria vary from 0.5 to 10 micrometers in size. Their outer membrane is freely permeable, it let’s in and out proteins less than 5000 daltons. The inner membrane, however is tightly regulated, nothing gets in or out without the special transport. Inner membrane forms cristae that curve inside to maximize the surface for energy production.
Have you ever watched the The İnner Life Of The Cell movie? You should. I’ve watched it many times, but I can’t get tired of that real beauty. The beauty of reality.
This video was produced by the scientific animation company XVIVO for the BioVisions program at Harvard’s Department of Molecular and Cellular Biology. The fascinating animation sheds light to what’s happening beneath the membrane of a leukocyte that interracts with an endothelial cell. You can see the cytosceleton, assembling actine fibers and microtubules, protein synthesis in the cytoplasm, a vesicle leaving Golgi apparatus and excreating what it had inside into the extracellular space and, of course, the kinesin, which paces proudly along the microtubule carrying its heavy load – a vesicle.
There’s another amazing video – Powering the Cell: Mitochondria « XVIVO. This one shows the ATP production in the mitochondia – a rather complex set of processes to understand if one’s just reading the description. I think this is how all textbooks should look like, especially in such complicated subjects as Biology. At some point of time in the future I hope to open up one of those books, or should I say click ‘play’?
Read more about miraculous scientific animations in New York Times
Avoiding disease, maintaining physical and cognitive function, and continuing social engagement in late life are considered to be key factors associated with what some gerontologists call “successful aging.”
First and foremost, let me strongly disagree here with those gerontologists. I believe the term “successful aging” is absolutely intolerable. Just think about it. How on Earth can aging be somewhat successful? Aging brings diseases, mental incapacity and other deteriorating effects on the human body. We cannot call that successful under any circumstances. So for the purpose of this article, we have replaced the term “successful aging” with “less destructive aging.”
While conducting studies of Amish families in Indiana and Ohio, a group of researchers led by William K. Scott, PhD, Professor of Human Genetics at the University of Miami Miller School of Medicine, began to notice that a significant number of people over age 80 in these communities demonstrated the three main factors associated with less destructive aging.