Cell Size & Diffusion

Purpose: Students will explain why cell size is limited by the process of diffusion by using a cell model constructed of an agar cube that contains an indicator (phenopthalein) in a solution containing sodium hydroxide (NaOH) .

Hypothesis:

IF cells require a large __________ :_________ratio for diffusion to meet the needs of the cell THEN the cell model that will show the greatest amount of diffusion will be the _____ cube after 10 minutes BECAUSE the ratio of surface area:volume _________ as cells become smaller.

Remember:

Surface Area = L x W x (#of sides)

Volume = L x W x H

See Picture Set below for Lab results and Data

Agar cube models placed into NaOH solution for 10 minutes

Agar cubes cut into half after being removed from the NaOH solution....NOTE measure the changes in color (diffusion depth) for each cube