Simple diffusion in cell membrane from wikimedia commons
Some questions to tackle this week:-
- Do you know what a phospholipid is?
- Can you draw a labelled diagram of a cell membrane?
- What other structures are present in the membrane to help it perform its function of allowing substances into and out of cells?
- How does this relate to diffusion?
- Can you explain why the membrane is described as fluid?
Here are some links to images and animations that might help you understand the answers to these questions.
Simple diagram of cell membrane. More complex diagram of cell membrane.
Animation showing that the cell membrane is selectively permeable by only allowing molecules that are small enough to pass across.
This animation shows how protein channels can help diffusion of larger molecules across the membrane.
This interactive animation explains diffusion and how it relates to membrane structure.