Nida Ali's Argumentation of Cell Size and Diffusion

Diffusion Cube Argumentation

My group members and I are supporting the explanation that cells that have a larger surface area to volume ratio are more efficient at diffusing essential nutrients. We used a variety of shapes and sizes that ranged from a small cube to a large cross. The cube with dimensions of 1cm by 1cm by 1cm was the first to dissolve at 15:28 minutes and had the largest surface area to volume ratio of 6:1. Quickly after, the small rectangle with the dimensions of 2cm by 1cm by 1cm  was the second to dissolve at 16:14 minutes with the second largest surface area to volume ratio of 5:1. The cubes that had the largest surface area to volume ratio were among the smallest cubes that diffused the weak acid quicker than the rest by reaching the center point of the cube from each side of the cube. Even though the small cross with a large surface to volume ratio of 4.4:1, it was the last to completely diffuse the weak acid at 33 minutes. Due to this occurrence, it refutes the claim that cells that have a larger surface area to volume ratio are more efficient at diffusing essential nutrients. Since my group members and I decided to compile all of the cubes into one container with the weak acid, some cubes were on top of one another. The small cross was at the bottom of the container, which resulted in limited amount of the cube (membrane) to be completely exposed to the weak acid as seen in the image below.  

Once placed in vinegar, the cells began to diffuse. Cells were piled on top of one another which slowed down the process of diffusion for the cells that were at the bottom of the container. The yellow edges of the cell represents that diffusion has taken place. 

The piled shapes took longer to diffuse since less area of the “cells” were exposed to the weak acid. In doing so, the smallest cross took the longest to diffuse since it was piled beneath the larger cube as well as the large cross. The large cube diffused at 24 minutes with a surface area to volume ratio of 3:1. In addition, the large cross with a surface to volume ratio of 2.2:1 finished before the large cube at 21:56 minutes which goes against the previously stated claim. The large cross should have been the last “cell” that diffused due to its small surface area to volume ratio. Since the small cross was piled on top of by the large cube and then by the large cross, the small cross and large cube took longer to diffuse. According to this claim, the “cells” with the smallest surface area to volume ratio should be the last one to fully diffuse. But this occurrence did not occur due to the piling of “cells”. If my group members and I decided to place each “cell” in their own container and allow it to diffuse, we would have seen that the “cells” with the larger surface area to volume ratio would have diffused first in comparison to the “cells” with the smaller ratios.

As seen here, the piling of cells
displays how the entire surface of the cell
not fully exposed to the vinegar in
comparison to the cells that are being
diffused fully due to complete exposure. 

This is what the cells looked like after they were fully diffused.
The remaining blue seen inside of one cell displays
the cell that diffused last due to remaining at the
bottom of the container. 

As seen in the left image above, the “cell” with the blue still remaining is the “cell” (small cross) that diffused last at 33 minutes due to it being piled at the bottom of container as seen in the image on the right.

The explanation that the rate of diffusion may relate to the size of the cell and sometimes the nutrients diffuse at a faster rate through small cells than they do through larger cells is what my group members and I are refuting against. The diffusion rate actually does relate to the size of the cell, but it does not support the idea that smaller cells are able to diffuse the nutrients at a faster pace than larger cells. Likewise, as seen in the large cross with the dimensions of 2cm of each side of the cross, it was typically larger than the large cube with the dimensions of 2cm by 2cm by 2cm. While figuring out the diffusion rate of the cells, we discovered that the cubes with 2cm by 2cm by 2cm made up a cube in the large cross, which thus states that the large cross is larger than the large cube since five large cubes are able to combine to form the large cross. Since the large cross had a larger diffusion rate of 2.5cm per 21:56 minutes than the large cube, which had a diffusion rate of 1cm per 24 minutes, the weak acid was able to travel faster over a longer distance. The large cube had a shorter distance to travel to the center point of the cube and did so at a slower pace than the larger cross. Even though the large cube is smaller than the large cross, it did not diffuse faster than the large cross which thus goes against the claim that nutrients diffuse faster in small cells than they do in large cells. The diffusion rate allows us to comprehend how far and quick the weak acid (vinegar) travels to the center of the cell, but the smaller the size does not mean that it will be able to diffuse to the center first, as seen in our experiment.