Understanding how cells move things in and out is really important for GCSE Biology. Here are some reasons why:

1. Basic Ideas: Cell membranes are like gates. They control what goes in and out of the cell. About 85% of things that happen in a cell involve moving stuff through these membranes.

2. Types of Movement:

   • Passive Transport: This doesn’t need energy. For example, diffusion is when substances move from places where there’s a lot of them to places where there’s less.
   • Active Transport: This needs energy (called ATP) to move substances against the normal flow. About 40% of a cell's energy goes to this type of transport.

3. Biological Activities: Moving things around is really important for processes like osmosis (the movement of water), taking in nutrients, and getting rid of waste. Around 70% of cells use osmosis to keep the right balance of fluids.

4. Exams: You will often see questions about these transport methods on tests. They can make up about 20% of the total marks in the Cell Biology section.