Most human cells regenerate, although each cell type experiences a different life span. The notion that all human cells replace themselves after a period of seven to 10 years is a myth.Continue Reading
LiveScience.com reports that most brain cells, such as cerebral cortex neurons, do not replace themselves when they die. However, most cells do replace themselves on a fairly regular schedule. For example, red blood cells regenerate in roughly four months and white blood cells in about a year.
FeelGuide.com indicates that the epidermis, the skin's outer layer, regenerates about every 35 days, while the liver is capable of completely replacing itself in about six weeks. In fact the liver can regenerate in its entirety even when only as little as 25 percent of it is left. Stomach lining regenerates every four days or so, although stomach cells that make contact with digesting food regenerate in five minutes.
NYTimes.com reports that while most cell molecules are replaced periodically, human DNA is not. In other words, the same DNA is passed along during the cell regeneration process, which is why human beings continue to exhibit many of the same physical traits over the years despite regular cellular regeneration taking place many times over.Learn more about Cells
Cell theory is the scientific theory that describes the properties of cells, primarily that the cell is the basic unit of life, and all living things are made of cells and all cells come from pre-existing cells. Modern cell theory is the result of centuries of research and experimentation facilitated by the invention of the microscope. Cell theory dispels the past myth of spontaneous generation or life coming from nothing.Full Answer >
Human cells feature a cell membrane surrounding two compartments: the cytoplasm and the nucleus of the cell. Each cell also has several organelles, or structures with specific functions.Full Answer >
Human cells do not have cell walls. Cell walls are multilayered structures that are unique to plants, bacteria, fungi and some protozoa. However, only plant cell walls are made out of cellulose.Full Answer >
ATP is called the energy currency of the cell, and of life, because it is the energy molecule that all cells need in order to do anything within the human body. The molecule is used like a battery within cells and allows the consumption of one of its phosphorous molecules.Full Answer >