The nucleoli of senescent cells will become larger, and the chromatin will consolidate, what is the

Cellular senescence: Nuclei increase in size.

Characteristics of cellular senescence:

1. Cells shrink with less water, become smaller in size, and slow down cell metabolism.

2. The activity of a variety of enzymes is reduced, such as the decrease in tyrosinase activity, and the decrease in melanin synthesis leads to gray hair.

3. The permeability of the cell membrane is changed, which reduces the material transport function.

4. The volume of the nucleus increases, the nuclear membrane folds inward, the chromosomes shrink, and the staining deepens.

Cellular senescence: Nuclei increase in size.

Analysis: The main characteristics of cell senescence can be summarized as "one large": the volume of the nucleus increases, and "one small":

Cell volume decreases, "one more": hyperpigmentation (such as the appearance of age spots), "three lows": metabolic rate, activity of some enzymes, and decreased material transport function.

The nucleus, cytoplasm and cell membrane of senescent cells all have obvious changes

Intracellular water decreases, the volume becomes smaller, and the rate of metabolism slows down;

decreased activity of intracellular enzymes;

Pigments accumulate within the cells;

The rate of intracellular respiration slows down, the size of the nucleus increases, the number of mitochondria decreases, and the volume increases;

The permeability function of the cell membrane is changed, which reduces the function of material transport.

One. To be precise, this phenomenon is called swelling of the nucleus. This question involves a lot of senescent cell changes, and the main ones are as follows:

1.As a result of cellular senescence, transcriptional capacity decreases, histone proteins decrease, and chromatin condensation decreases, affecting the transcription of related proteins.

2.The composition of the nuclear skeleton changes, the nuclear fiber layer has a supporting role in the nuclear membrane, and the cell aging causes the structure of the nuclear fiber layer to loosen, and the supporting role of the nuclear layer is reduced.

3.Alteration of ion concentration: due to cell aging, the stability of the nuclear pore complex and nuclear membrane decreases and permeability increases. The extremely strict difference in the concentration of ions inside and outside the nucleus affects the tension of the membrane and the concentration and amount of the internal nuclear matrix, resulting in the swelling of the nucleus.

Two. Because the cell enters a state of programmed death, it is also called apoptosis. This is the pathway for senescent cells to die. More details have not yet been studied.

Three. The senescence of cells is mainly determined by the senescence of the nucleus! This is related to factors such as decreased telomerase activity, shortening of the DNA molecule, and methylation modifications! It's not something that can be explained in a sentence or two. The increase in the size of the nucleus may be a characteristic manifestation of the regulation of aging.

Four. In Mr. Cheng Kwok-cheung's "Cell Biology", there is no increase in the volume of the nucleus in the description of the characteristics of cell aging, but he points out that the ratio of the nucleus to the cytoplasm decreases, and the growth rate gradually decreases, and even some cells eventually even disappear from the nucleus, such as mammalian red blood cells.