[Creature]-There are limits on how to understand the number of cell division.

Source: http://hi.baidu.com/ccd2093/blog/item/3248302da2405736349bf71a.html

 

The reason why humans die is that human cells are split for a limited number of times. For example, fiber cells can only breed for 50 generations, and then they will inevitably die. but what I don't understand is that a mother cell is split into two cells, and the two cells should be the same. The number of Split times decreases accordingly until 50th generations, cannot be split. but in this case, for single-cell organisms, there is also a limit on the number of splits. Isn't it necessary to become extinct long ago? Is there a problem with my understanding? One mother cell splits into two cells, one of which is the Mother Cell and the other is the Child cell. Can the child cells still generate 50 generations, and the Mother Cell can only breed 49 generations? But in this way, it's not that people can't die again, because there are constantly updating cells.

 

 

 

Ccd2093 we recommend you read a document first. This document is good and easy to understand.

So far, contemporary science has not yet provided an accurate explanation of the causes and Mechanisms of aging, we have not proposed a systematic theoretical or practical countermeasure for the end of aging and aging-death.

Scientists have used experiments to prove that, for single-cell organisms, cells cultured in vitro can be split as long as the conditions are appropriate. But is it true that the cells of a large multi-cell collection are the same? The scientific fact is irrefutable: No.

In September 1961, scientists used fiber cells for in vitro culture, proving that the fiber cells pass through the process ~ After 50 split times, the cells become larger and the cell cycle becomes longer (from 21 h to 24 h or more), and eventually no longer splits and dies. The experiment further proves that, the number of Split times of fiber cells is also fixed. After 20 split fiber cells are frozen for several years, they can still be split for about 30 times and then aged and died. In addition, it can be further proved that the "Clock" that determines the number of splits seems to exist in the nucleus. For example, if you move 10 split fiber cells into 30 split fiber cells and remove the original nucleus, the cell of the young nucleus will split 40 more times based on the number of split of the young nucleus. Otherwise, if you replace a split nucleus that has been split for 30 times with a split nucleus that has been split for 10 times, then the cell with the "old new kernel" can only be split for about 20 times. In addition, fiber cells in the elderly are slower than those in young people, and can be split less frequently during in vitro culture. The above scientific experiments and facts fully prove that fiber formation has a certain life cycle, and will always die from aging unless the cancer occurs. The essential reason is that the number of Split times of fiber cells is fixed.

Speaking of this, someone may come up with hula cells as a counterexample to refute the above ideas. Indeed, hula cells do not seem aging. The lady has been away for nearly 50 years, but the cells from her cervical cancer continue to split and multiply. This seems to indicate that cells have the ability to get rid of aging and "keep young ". Even fiber cells with fixed life cycle can no longer die from aging if they become cancer. However, what I want to point out here is that haila cells are abnormal cells, and normal fiber cells with fixed life cycle become abnormal cancer cells, "youth forever" appears ". This means that a normal person without cancer will suffer from cell aging, which eventually leads to death. The cells of an abnormal human with cancer will eventually return to the normal state of nature due to being "squeezed out of normal.

The following further demonstrates what factors have prevented the split of fiber cells. Existing experiments have showed that the old fiber cells are used to promote cell division molecules, such as platelet growth factor (FIB) and growth factor from epithelial cells) neither insulin nor insulin is sensitive, and some necessary transcription functions are lost. They can only stay in stage G0, but cannot enter stage G1 to re-split, and eventually become aging and die.

Cancer cells have many differences with normal cell division due to changes in the genetic material or genomic composition of cells. Cancer cells continue to split without being influenced by adjacent cells, and thus become a multi-layer culture of bulge. This is because the surface of cancer cells changes and there is no longer any contact inhibition, so they do not know each other, and other cells, so they move around in the body, leading to the transfer of cancer cells. The split of cancer cells is not restricted by the two control points in the cell cycle. Therefore, as long as there is no nutrient, the split can be infinitely split and can be stopped at any time, therefore, the number of chromosomes varies greatly.

From the perspective that cancer cells can survive and become fiber cells always die after aging, it seems that the life of cells determines the cell itself. That is to say, aging is the genetic property of cells, so cells always need to aging. Changing conditions may regulate the expression of aging genes, thus delaying cell aging, or even making aging genes unavailable, such as cancer cells. However, in general cells, although aging may be delayed, aging always occurs.

 

After ccd2093, note: we have actually explained an important biological clock theory. For example, a human's cell division is determined by the biological clock for 50 times. A chicken's cell division is 25 times that a mouse splits only 12 times. However, there are still some ways to prolong the life. For example, scientists have found that cell division speeds are variable and slow at low temperatures, while algebra does not change but the lifetime can be prolonged. Therefore, it is suggested that if the temperature of a person is reduced by 2 degrees Celsius, the life cycle can be extended to 200 years. If the temperature is reduced by 4 degrees Celsius, the person can live for 700 years, and the quality of life remains unchanged. Some people think that reasonable and beneficial hunger can greatly improve people's life, which is also due to the principle of slowing down the speed of cell division. Therefore, it is currently believed that the life cycle of humans and animals is specific inheritance. Program It is decided that the current situation cannot be changed, and the aging of people is inevitable at this stage.