# Surface area to volume ratio effect on diffusion

The result here is higher than the curve of best fit for the graph. Extracts of this project must not be included in any projects that you submit for marking. I tried to keep all the variables except for the size of the gelatin blocks the same for all the experiments.

It takes longer to reach the centre of the cube even though the rate of diffusion is the same for all the cubes. A better overall result would be obtained by repeating the experiment more times because any errors in one experiment should be compensated for by the other experiments.

Anomolies The graph produced shows a smooth curve with a decreasing gradient as the surface area to volume ratio goes up.

The concentration of oxygen in the cell is always lower than outside the cell which causes the oxygen to diffuse in. This would ensure that diffusion could occur evenly through all the sides of the cube. The lungs have a very large surface area because they contain millions of sacs called alveoli which allow oxygen to diffuse into the bloodstream.

Larger organisms such as mammals have a relatively small surface area compared to their volume so they need special systems such as the lungs in order to get enough oxygen.

You have been warned. The line of best fit for the graph suggests that the average should be around 3 seconds. Surface area to volume ratio is very important in lungs where a large amount of oxygen has to get into the lungs. A small cradle could be used to suspend the blocks in the acid which would mean that all six sides of the cube should be in contact with the acid.

Doing this could lead to being disqualified from all the subjects that you are Surface area to volume ratio effect on diffusion.

This surface area is sufficient for all the oxygen we need to diffuse through it and to let the carbon dioxide out. The results for the 5 x 5 x 5 block ranged from 4. The anomalous result was probably due to experimental error as a result of this being the first block size that I used in the experiment.

The most likely explanation is that I was unsure of how to judge when all the dye had disappeared and as a result delayed pressing the stop button of the stop watch. Disclaimer This is a real A-level school project and as such is intended for educational or research purposes only.

If you like this post please consider linking to it using this code: It is important that cells have a large surface area to volume ratio so that they can get enough nutrients into the cell. A living cell would not survive if it had to wait 48 minutes for oxygen to diffuse through it so living cells need to be very small.

Interpretation In all the blocks of gelatin the rate of penetration of the hydrochloric acid from each side would have been the same but all the blocks take different amounts of time to clear because they are different sizes.

When the surface area to volume ratio goes down it takes longer for the hydrochloric acid to diffuse into the cube but if the ratio goes up then the hydrochloric acid diffuses more quickly into the block of gelatin. The only anomaly is the result for the 5 x 5 x 5 block. This means that the hydrochloric acid is able to diffuse to the centre of the smallest block much faster than the largest block.

The cell membrane is made up of a lipid bi-layer with many proteins integrated into it. By having millions of these alveoli the lungs are able to cram a very large surface area into a small space. Single celled organisms such as amoebas have a large surface area to volume ratio because they are so small.

The larger blocks have a smaller proportion of surface area than the smaller blocks. The smallest block has 1. They can increase their surface area by flattening and becoming longer or by having a rough surface with lots of folds of cell membrane known as villi.

By increasing the surface area the rate of diffusion will go up. The largest block only has 0. Extension Work This experiment could be improved in a number of ways. As the blocks get bigger it takes longer for the hydrochloric acid to diffuse through all the block and so clear the dye.

However, in reality it is impossible to keep all the variables precisely the same. As the experiment progressed with the other block sizes I probably got better at making this judgement. I measured the sizes to the nearest mm so the sizes of block that I used should be correct to the nearest mm.

The concentration of carbon dioxide outside the cell is lower than the concentration in the cell so the carbon dioxide will always dissolve out of the cell. Some shapes have a larger surface area to volume ratio so the shape of the object can have an effect on the rate of diffusion.

Limitations To help make this experiment more accurate, I repeated it three times for each block size and then used the average of all the results to plot a graph with a line of best fit. Precautions a All the gelatin used should be taken from the same block to ensure that all the blocks are made up of the same materials.

The acid took 48 minutes to diffuse to the centre of the largest block but only 1 minute in the smallest block.• To investigate the effect of a change in the surface area to volume ratio on the rate of diffusion.

• Determine how surface area and volume relate to one another Hypothesis If the size of the jelly is large, then the rate of diffusion will be lower. If the surface area of the cell increases, then the rate of diffusion will decrease.

As the agar cubes were cut smaller the ratio of surface area to volume became larger and this affected the diffusion rate by making it faster.

The results show a clear trend that supports my knowledge on how the diffusion rate speeds up when there is a larger surface area to volume ratio. Surface area to volume ratio, in simple means the size of surface area to the volume of substance that can pass through it at a particular time.

Amoeba and some bacterias are flat and have large surface area to volume ratio. So the diffusion rate is very high due to large surface area. How do surface area and volume affect diffusion? Update Cancel. Surface area/ volume ratio controls the the diffusion rate through membranes/ semipermeable membranes.

In a spherical body, like a bacterial cell, when the ratio is more than 1 (like in newly divided cell, more solutes diffuse in the cell from the aqueous outside. Some shapes have a larger surface area to volume ratio so the shape of the object can have an effect on the rate of diffusion.

It is important that cells have a large surface area to volume ratio so that they can get enough nutrients into the cell. Surface Area to Volume Ratio and the Relation to the Rate of DiffusionAim and BackgroundThis is an experiment to examine how the Surface Area / Volume Ratio affects the rate of diffusion and how this relates 3/5(1).

Surface area to volume ratio effect on diffusion
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