Surface Area to Volume Question?

Question

Why is the theory of SA:V important to limiting cell size? Isnt the bigger the ratio the better diffused a cell is? I did an exercise where i had to build two different sized people. one was big and one was small. But they both had the same volume and different surface areas...did i measure it wrong? thank you ^^

Answer 1

Consider how a cell gets its nutrients and how much nutrient is required to sustain a cell. The amount of required nutrient is proportional to the volume of the cell. How fast it can get nutrients is proportional to its surface area.

That means that the ratio of required food to ability to acquire food is proportional to R, assuming a spherical cell for simplicity. That means that at some point, an ever increasing cell size would outstrip the cell's ability to get nutrients.

Answer 2

Because the surface area of any object is proportional to the square of its average linear dimension, whereas the volume is proportional to the cube.

To get a better idea of this, consider a cube of length=3 units on each edge. The edge is the linear dimension; when you put 4 edges together at right angles you form a square, which has an area of not 3 but 9 units, or 3-squared.

Now if you stretch this square into the third dimension to make a cube, its volume is 3x3x3 or 27 units-cubed.

So as a cell grows bigger, its volume increases faster than its surface area, and that makes it more difficult for enough material to move in and out of the cell. This puts a size limit on how big functional cells can be.

Answer 3

There are many factors that limit the SA:V ratio. A sphere has the best volume/surface area ratio. But, to address your example, which person was colder? Heat loss is a problem with larger surface areas. More area=greater heat loss and cells have to maintain a given temperature for activity to ocurr in that cell. Animal cells also have a phospholipid bilayer membrane and not a cell wall like bacteria have. This means that, like an overfilled water balloon, when the cell gets to big, it will rupture (its SA increases but the volume increases faster).

Answer 4

Think of a sphere that is 1" in diameter, compared to one that is 2" in diameter. The larger sphere has twice the diameter, 4 times the surface area, and eight times the volume.... in other words, only half the SA:V ratio of the smaller sphere. Cells need a large SA:V in order for gases to be able to diffuse to their interior.

It is possible to increase the SA:V for a given objectby making its surface more wavy or crinkly: that increases the syrface area without changing the volume.

Answer 5

that's the heaviest solids if weight and shape have been the identity features. Take 2 gadgets of same weight and shape. The densest one, consisting of plutonium might have least quantity. extremely those days 2 new factors have been got here across at Berkeley - 116 and 118 (pointed out via their style of protons). yet once you're in seek of a shapewise answer then it would be a flat sheet. The flatter, the extra suitable to fulfill your requirement to shrink quantity to floor. and that i declare that is not any longer correct what 2 dimensional shape it took see you later because it became flat. As a theory test, think of that an merchandise ought to be flattened all the way down to a million molecule thick. you will have all molecules uncovered and the section may be the portion of a million molecule situations the style of molecules interior the article. So the two dimensional shape would not be counted. Flatness is the main.

Answer 6

Unfortuanettly you might have calculated it wrong.The smaller a cell is the better because if it is small it is easier to work in and easier to send information back and forth.