Definition of Cell Cycle

All the living creatures are formed from cells. Their sizes and functions may be different, but they all have in common the presence of three structures: a membrane, the cytoplasm and the genetic material found in the nucleus. The membrane is the layer that surrounds the cell, protects it from the external environment and allows the function of nutrition.

The cytoplasm is a substance that is located between the membrane and the nucleus and is where all the organelles are. The nucleus is the most important organ, since it regulates the functioningmobile and it is also the center where the genetic material that is transmitted from one being to another is found.

The cells of an organism have a life cycle in which there are different stages. Each stage has a specific function.

Stages of cell development

There are stages g or also called stages of growth (the letter g is used, since it comes from the English grown, which means precisely growth). During this period or stage the cell grows in the number of organelles and thus prepares itself for when the moment of cell division arrives (during this stage the synthesis of

protein). On the other hand, the cell grows by increasing its volume. In this phase the duplication of the DNA, which is the most specific of the synthesis phase. When the cell is ready, the phase of mitosis or meiosis occurs depending on the type of cells. It should be noted that some types of cells do not divide, as occurs with neurons in the brain.

Regulation of the cell cycle

If conditions are optimal, some eukaryotic cells can divide every 20 minutes. However, the frequency of cell division varies depending on the species and the tissues.

In optimal nutritional conditions, temperature and PH the duration of the eukaryotic cell cycle is constant for each cell type. It should be noted that there are certain regulatory molecules in all eukaryotes that control the cell cycle.

These regulatory molecules are found in all kinds of organisms alive and thanks to them a sequence of specific events are triggered within the cell cycle. These molecules act as genetic programs and allow each stage of cell development to be can be completed properly (for example, if a cell produces damaged DNA, the cell cycle interrupts).

Among the molecules that intervene in the regulation of the cell cycle, we must highlight the protezymes, which are enzymes that activate other proteins by phosphorylation, which is the metabolic process that allows the cellular respiration.

Photos: Fotolia - Azuki / besjunior

Cell Cycle Topics