Imagine a spherical cell with a radius of 10 μm. What is the cell...

Question

Imagine a spherical cell with a radius of 10 μm. What is the cell's surface area in μm2? Its volume, in μm3? (Note: For a sphere of radius r, surface area = 4πr2 and volume = 4/3πr3. Remember that the value of π is 3.14.) What is the ratio of surface area to volume for this cell? Now do the same calculations for a second cell, this one with a radius of 20 μm. Compare the surface-to-volume ratios of the two cells. How is this comparison significant to the functioning of cells?

Accepted Answer

Hey everyone. Let's take a look at this question together. Surface volume ratios are critical for nutrient exchange between cells and their surroundings. Cells are microscopic in order to maintain the blank surface volume ratios needed to blank the rate of exchange of substances. So let's recall what we know about surface volume ratio as well as nutrient exchange and how that relates to the size of a cell. So we know when we're talking about the surface volume ratio in respect to the size of a cell, we know that a large cell as a low surface area to volume ratio and this low surface area to volume ratio means that they can exchange substances fast enough. So if they consume too much food they could lead to death or they'd run out of space to store that food so it could lead to starvation. And so cells want to have a high surface area to volume ratio. Which means they have to be super small because of that inverse relationship. So a small cell as a high surface area to volume ratio. So we can go ahead and eliminate answer choice C. And D. Because we need high we're talking about a high surface area to volume ratio. And cells are microscopic. And so when we're talking about that rate of exchange we're talking about how fast the cells can release the waist so that they can continue to consume food to prevent that death and starvation. And so in order to do that they need to maximize that exchange rate because of the surface area to volume ratio. Making answer choice a the correct answer. Because we know that since cells are microscopic, they have a high surface area to volume ratio. And because of that high surface area to volume ratio, they have to maximize the amount of space that they have to have that high rate of exchange of substances. So answer choice A is the correct answer. I hope you found this video to be helpful. Thank you and goodbye.

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