Mitochondria

Mitochondria can allow life or kill us. Mitochondrial DNA has only 37 genes. From those 37 genes comes just 13 proteins. Those 13 proteins code for the electron chain transport complexes. The remainder of the genes code for tRNA. Mitochondria also cant grow outside the cell. They require the 30,000 genes in the nucleus to make up another 1500 proteins for them to function. Mitochondrial DNA and nuclear DNA have to have precise lock and key fit to generate energy production. If not, the cell eliminates itself by apoptosis (levee 19) fast. If It works well, this combination is naturally selected for future cell division to generate energy. Aging is quantified by how "leaky" our mitochondria are to free radicals at complex ones in electron chain transport. Their own DNA is adjacent to the first complex in electron chain transport. So the more leakage, the more damage is done to its DNA and energy production will fall. Moreover, that is the signal to make more mitochondria or undergo cell suicide! This first complex (NADH) is by far the most leaky to free radicals of all the complexes. This paradox of fate caused evolution to select for 10-20 copies of mitochondrial DNA in each cell to sustain energy production of an organ in question. So mitochondria can breathe life into us and end it based upon how many good mitochondria we have in a tissue.

Now, we know definitely that Leptin controls all energy production by regulating all the hormones in the body. But, do you wonder what happens when that regulation goes awry in the muscles? Well, here is some information about one part of how Leptin works to keep us fit when your body is sensitive to it. When Leptin was discovered in 1994, no one really had a clue as to its many functions. One function that was particularly murky was how the brain controlled peripheral energy utilization and optimized it. It is awfully hard to realize that the hypothalamus (size of a pea) can control the need for fuel of 20 trillion cells in the human body. Well in the last few years, scientists found out about uncoupling proteins (UCP). So far five have been discovered in mammals. The one we will discuss today is UCP3. This protein, UCP3, allows Leptin to work inside of peripheral cells like the muscle cell. For UCP3 to work optimally, it requires optimal functioning of Leptin and thyroid hormone simultaneously. In muscle cells, UCP3 is the dominant UCP in humans. So it is vital to maximizing efficiency in exercise and energy use. What UCP3 allows the muscle to do, is to shift out of regular oxidative energy production done at the mitochondria and making energy in the form of ATP, and into making pure heat without generating ATP. This biochemical action decreases ROS (levee 3) at the mitochondrial level, decreasing cellular stress. And therefore the energy is dissipated mostly as heat. Another protein, UCP1, is dedicated to doing this same action when it is activated 100{a7b724a0454d92c70890dedf5ec22a026af4df067c7b55aa6009b4d34d5da3c6} of the time.