Biology on Surface Area to Volume Ratio Essay Example

As we all know, many chemical reactions happen within both unicellular and multicellular organisms. Many useful substances have to diffuse into different cells in order to help provide the necessary energy needed for these reactions to happen, at the same time, the waste products produced after these reactions have taken place have to be removed and excreted. As the organism increases in size through growth, more chemical activity will have to happen and the rate of metabolism will also increase, which means that more substances have to be taken in and to also be removed. This is where the surface area to volume ratio comes into place; the reason why this ratio is so important is because the surface area of a cell essentially affects the rate of the transferring of useful substances (through diffusion and osmosis etc.) in and out of the organism. On the other hand, the total volume of the organism also affects the rate of the making of material inside the cell and the ability to hold all of the substances. Whilst organisms are slowly growing and developing day by day, the volume of the organism increases, but not to the same extent as the surface area; this is because the organisms’ surface area increases at a much slower rate than its volume. Through research and experiments, it is apparent that as the organism grows, its surface area to volume ratio slowly decreases, the table to the right also proves that this theory is true; meaning that it would become increasingly difficult for the organism to obtain the required nutrients and also expelling the wastes produced by metabolism. In the end, it becomes impossible for diffusion to occur efficiently, where the cells becomes too large so they would divide through the process of mitosis. For example, the alveoli in our lungs have a relatively high large surface area to volume ratio, meaning that gas exchange in humans happen at a fast and efficient rate; the alveoli has a large surface area for diffusion to happen,