Question: how do fatty acids get inside cells?

Anais Kahve answered on 8 Mar 2016:

Excellent question! Firstly, let me explain a bit about a cell. Cells are basically bubbles: the outside of the bubble is made up of fats, proteins and carbohydrates which forms a layer to protect the inside of the cell. This outer layer is called the plasma membrane. In the 1970s it was believed that fatty acids entered cells via a process called ‘passive diffusion’ through the plasma membrane. This meant that the fatty acids, no matter what their shape, could go through this membrane freely and without any help. But in the early 2000s evidence suggested that actually this isn’t the case and that some proteins that are embedded in the plasma membrane help the fatty acids go through the plasma membrane. Scientists have found many proteins to be involved in this process by removing them and seeing how much fatty acid goes through the plasma membrane. But no one has tried to see ‘why’ some proteins are more essential than others or ‘how’ the structure of the fatty acid actually makes it more likely or less likely to pass through the plasma membrane. Some scientists are developing drugs that target some of these proteins to prevent fatty acids from entering cells but these have not been successful. If we can better understand what is happening at a molecular level then we can make better drugs.