AP Bio - SA:V

What single factor limits the size that most cells are able to obtain?

SA:V ratio. The metabolic activity depends on the SA:V ratio.

What is the advantage of having many small cells instead of few large cells?

Having more smaller cells rather than fewer larger cells is more efficient because overall, the cells metabolism will be faster. Having fewer larger ones is more risky because cells could die easier and or not have the needed surface area for efficient metabolism.

Does the volume of a cell increase or decrease more rapidly than the surface area?

Increase

How is a cell's potential growth affected by its ratio of surface area to volume?

A cells SA:V decreases as the cell grows larger. The volume increases more rapidly than the surface area resulting in problems in transportation of materials and information demands. Therefore, cellular growth is dependent on metabolic activity. As a result, cellular growth can either be limited or boundless by the SA:V ratio.

Does a cell need a low or high SA:V ratio?

Low

What problems are face by a cell as it increases in size?

As a cell increases, information crisis is can occur. This means that there are more demands on DNA that DNA cannot meet. Too much DNA is being requested, and the cell cannot keep up. Also, too many materials, such as nutrients and waste, are produced due to the large volume. The surface area is too small for the amount of materials produced.

How does the surface area to volume ratio change as the cell grows larger?

As the surface area of a cell increases by n2, the volume increases by n3. The volume increases more rapidly than the surface area.

Why is the surface area of the cell critical for the survival of the cell?

Surface area is highly important to the rate of metabolism. Metabolism includes all of the cellular reactions required for cellular survival. The faster the reactions the better the survival. As cells get larger, The metabolism slows down due to the large surface area in which materials travel across. The larger the surface area the longer it takes for materials to travel across. The smaller the cell the metabolism is increased. Therefore, the smaller the surface area the better rate of survival for the cell because of increased metabolism.

How does the flatness of a cell affect the SA:V ratio?

The surface area is actually larger than the volume in this case. The volume stays the same.