Factors which limit cell size

Each internal region of the cell has to be served by part of the cell surface. As a cell grows bigger, its internal volume enlarges and the cell membrane expands. Unfortunately, the volume increases more rapidly than does the surface area, and so the relative amount of surface area available to pass materials to a unit volume of the cell steadily decreases. Finally, at some point, there is just enough surface available to service all the interior; if it is to survive, the cell must stop growing.

Surface Area to Volume Ration. A cell cycle is a series of events that takes place in a cell as it grows and divides. A cell spends most of its time in what is called interphase, and during this time it grows, replicates its chromosomes, and prepares for cell division. The cell then leaves interphase, undergoes mitosis, and completes its division. Every time chromosomes reproduce, telomeres get shorter. As telomeres dwindle, cell division stops altogether.

Incorporating stem cell-friendly foods into your diet is a tremendous first stem to boosting promoting natural cell growth. Intermittent fasting is a stem cell activator and has been found to trigger rapid cellular regeneration. Hematopoietic growth factors are hormone-like substances that stimulate bone marrow to produce blood cells. Prolonged fasting forces the body to use stores of glucose and fat but also breaks down a significant portion of white blood cells.

During each cycle of fasting, this depletion of white blood cells induces changes that trigger stem cell-based regeneration of new immune system cells. Smaller single-celled organisms have a high surface area to volume ratio, which allows them to rely on oxygen and material diffusing into the cell and wastes diffusing out in order to survive. The higher the surface area to volume ratio they have, the more effective this process can be. Larger animals require specialized organs lungs, kidneys, intestines, etc.

Increased volume can lead to biological problems. King Kong, the fictional giant gorilla, would have insufficient lung surface area to meet his oxygen needs, and could not survive. For small organisms with their high surface area to volume ratio, friction and fluid dynamics wind, water flow are relatively much more important, and gravity much less important, than for large animals. However, increased surface area can cause problems as well.

More contact with the environment through the surface of a cell or an organ relative to its volume increases loss of water and dissolved substances. High surface area to volume ratios also present problems of temperature control in unfavorable environments. Learning Objectives Describe the factors limiting cell size and the adaptations cells make to overcome the surface area to volume issue.

Key Points As a cell grows, its volume increases much more rapidly than its surface area. Since the surface of the cell is what allows the entry of oxygen, large cells cannot get as much oxygen as they would need to support themselves.