U2 Topic 2-Cell size video notes

Use the formulas provided to calculate SA:V ratio and determine which cell option would have the highest SA:V ratio. Then continue the video to see if you were correct.

Which size cell will always be best at exchanging material through the plasma membrane?

• Large cell

• Small cell

Practice problem 1. SA:V ratio: ____ (round to a hundredth. Example 1.00)

Practice problem 2. SA:V ratio: ____ (round to a hundredth. Example 1.00)

5. Practice Problem #5. Calculate the SA of a spherical cell with a radius of 2um: _________ (round to nearest hundredth)

5. Practice problem #7. Calculate the Volume(V) of a spherical cell with a radius of 7um: __________(round to the nearest hundredth)

9. Practice problem #9. Calculate the SA:V ratio of a spherical cell with a radius of 12um: __________ (round to the nearest 100th)

Practice problem #10: Calculate the SA:V ratio of a spherical cell with a radius of 8um:________(round to the nearest hundredth)

Eukaryotic cells can reach above 100μm in diameter, while prokaryotic cells, like bacteria, remain

small, reaching only to about 10μm in diameter. How are eukaryotic cells able to become so much

larger than prokaryotic cells while still efficiently exchanging material through the plasma membrane?