Bacteria were among the first life forms to appear on the face of the Earth and have the uncanny ability to overcome even the harshest of environments, from acidic hot springs to the ice-fields of the poles and deep portions of the Earth’s crust. They are so abundant, that they make up the majority of the total biomass on earth. Astonishingly, nearly 90% of the cells that move around with humans are actually bacteria , though since they are so much smaller than human cells, they make up only about 10 percent of our body-weight. Continue reading
The human brain is the most powerful computer the world has ever seen. With its 86 billion neurons , less than originally thought (~100 billion, a myth of unknown origin ), the human brain is still at the top of the list and capable of remarkable feats, not only as far as computing power is concerned, but it is capable of self-programming, reasoning, data storage, and affords intelligence; at least in most cases. By comparison, digital computers are dumb slaves that do the bidding of their masters, the programmers, and rely on fixed nuts and bolts for their functioning. Furthermore, even the fastest computer currently in service, the Chinese NUDT Tianhe-2 with a capacity of 33.86 petaFLOPS (1015 FLoating-point Operations Per Second) , is only capable of handling one problem at a time and sequentially one bit at a time. The human brain’s computing is significantly slower, but Continue reading
Antioxidants are a direct consequence of the highly oxidizing environment (21% atmospheric dioxygen) in which we live on the third rock from the sun. The switch from anaerobic to aerobic metabolism during the evolution of the majority of organisms on this planet not only resulted in a more efficient liberation of energy from glucose (~30  vs. 2 ATP), but came at a price, since dioxygen has several alter-egos. With two unpaired electrons, dioxygen is a typical free radical, albeit that its chemistry is constrained; however, all hell breaks loose when this constraint is lifted and various highly reactive oxygen species (ROS) are formed.
The phosphoprotein p53 was trivially named after the apparent molecular mass it runs on SDS-PAGE, i.e., 53-kilodalton (kDa). Ever since its discovery in 1979 by several groups simultaneously, this extraordinary protein has captured the imagination of life scientists. p53 is likely the most extensively studied protein in cell biological research. To underscore its importance, p53 has been called a “cellular gatekeeper”  or “the guardian of the genome” , and for a long time researchers believed that p53 was the universal master switch that defined cancer onset and progression. However, this turned out to be not entirely true. Nonetheless, at least half of all cancer types carry aberrations in the p53 gene (TP53). p53 acts as a decision nodule that organizes the cell’s response to stress. Continue reading