The Data Table:
Questions:
1. In terms of maximizing diffusion, what was the most effective size cube that you tested?
In terms of maximizing diffusion, the most effective sized cube that we tested was the 1cm cube with a SA:V ratio of 6:1. It had the highest diffusing rate of about 73%, while the 2cm cube had a diffusion rate of 45% and the 3cm cube had the lowest rate of 30%.
2. Why was that size most effective at maximizing diffusion? What are the important factors that affect how materials diffuse into cells or tissues?
The 1cm cube was the most effective size at maximizing diffusion because it had a large surface area ratio and a smaller volume ratio (6:1). For a cell to diffuse effectively, it must have a large surface area and a small volume. The surface area represents the plasma membrane in the cell, and the more plasma membrane it has compared to the volume the more materials it’s effectively able to transport within the cell (Meehan, 2021). The important factors that affect how materials diffuse into cells or tissues would be the temperature, concentration gradient, the polarity, the shape and size of the cell, and the specific type of material that is used.
3. If a large surface area is helpful to cells, why do cells not grow to be very large?
Cells don’t grow very large because as the surface area of the cell becomes larger, so will the volume of the cell and they won’t have that large membrane. The volume would become larger at a faster rate than the surface area. This would then result in a decrease in the SA:V ratio, and the cell not being able to diffuse very effectively. Even though the cell would have a large surface area, the volume would also grow becoming much larger than the surface area.
4. You have three cubes, A, B, and C. They have surface to volume ratios of 3:1, 5:2, and 4:1 respectively. Which of these cubes is going to be the most effective at maximizing diffusion, how do you know this?
The cubes that would be the most effective at maximizing diffusion would be cube c, which is the 4:1 ratio. This cube would be the most effective because as mentioned before the cell/cube with the largest surface area and smallest volume will have the highest rate of diffusion. This allows for substances to enter and the leave the cell in an effective manner.
5. How does your body adapt surface area-to-volume ratios to help exchange gases?
Our bodies have adapted to surface area-to-volume ratios to help exchange gases by having large organs with large surface area to volume ratios. For example, in the lungs tiny sacs called alveoli contribute to a high surface area to volume ratio due to being folded into many tiny sacs. This creates a much larger surface area for gas exchange to effectively occur in the lungs (Vanstone, 2022).
6. Why can’t certain cells, like bacteria, get to be the size of a small fish?
Bacteria cannot become the size of a small fish because when they grow the surface area and volume would increase. Consequently, this would result in the volume growing at a faster rate than the surface area and then there wouldn’t be as high of a diffusion rate. As, the SA:V ratio would start to decrease and not increase. If the SA:V ratio begins to decrease and the bacteria gets too large, then it begins to divide to obtain that ideal SA:V ratio.
7. What are the advantages of large organisms being multicellular?
The advantages of large organisms being multicellular would be they are much more complex, which results in many varieties of cells that would have different ranges of jobs. For example, there would be different types of cells for each organ systems in the body. This helps the organism to become much more efficient, live longer, and have better ranges of movement. When the cells work together, it will also result in less stress as there isn’t just one cell that is performing every single function inside the organism. A large organism being multi-cellular can also eliminate the size limits that diffusion has, and they can continue to divide cells that are efficient at diffusing (Miller, 2017).
Citations:
Meehan, Elizabeth. “Cell Size & Surface Area to Volume Ratio.” Study, 23 Dec. 2021, https://study.com/academy/lesson/cell-size-scale-surface-area-volume-ratio-organelles.html. Accessed 5 Mar. 2023.
Miller, Brandon. “8 Pros and Cons of Multicellular Organisms.” Greengarageblog, 12 Jul. 2017, https://greengarageblog.org/8-pros-and-cons-of-multicellular-organisms. Accessed 5 Mar. 2023.
Vanstone, Emma. “Sugar Cube Surface Area to Volume Ratio Investigation.” Science-Sparks, 3 Feb. 2022, https://greengarageblog.org/8-pros-and-cons-of-multicellular-organisms. Accessed 5 Mar. 2023.