Internal and external regulators are crucial components in the control of biological processes, particularly in the context of cell division and growth.
Internal Regulators: These are proteins that respond to events occurring inside the cell. They help ensure that the cell cycle progresses only when certain conditions are met, allowing for proper surveillance of the cell’s internal environment. For instance, if DNA is damaged, internal regulators can halt the cell cycle to allow for repair mechanisms to take place. This helps prevent the propagation of mutations and ensures that cells only divide when they are ready.
External Regulators: In contrast, external regulators are signals that come from outside the cell. These include growth factors and hormones that bind to receptors on the cell surface and trigger responses that can promote or inhibit cell growth and division. For example, when a tissue is damaged, external regulators facilitate healing by promoting cell division in the affected area. Conversely, if cells are crowded, they may receive signals that inhibit further growth.
In summary, while internal regulators focus on the cell’s internal condition, external regulators oversee external conditions impacting the cell. Both are essential for maintaining the health of cells and the overall organism.