In I/GCSE Biology, there are two ways that dissolved substances move in and out of Cells. 🤓
- Diffusion is where Substances move along a concentration gradient which must be in the right direction for it to be useful to cells.
- Osmosis depends on a concentration gradient of water and a partially permeable membrane. Only water moves in osmosis.
However sometimes substances needed by your body have to move against a concentration gradient (A difference in concentration levels), or across a partially permeable membrane. This process is known as active transport.
Active Transports 👇👇👇
- Active transport occurs in plant roots to get nutrients from soil into cells
- it also let marine animals to move the salt they take In from the sea into high concentrated salt glands.
Active transport allows cells to move substances from an area of low concentration to an area of high concentration (This is the opposite of Diffusion). 🧐🧐🧐
- This means that substances move against the concentration gradient.
- This also means that cells can absorb ions from very dilute solutions, and makes it possible for them to move substances like sugars and ions from one place to another through cell membranes.
It takes energy for the active transport system to carry a molecule across the membrane and then return it to its original position. This energy comes from Cellular Respiration. The higher the rate of respiration, the higher the rate of active transport. Cells involved in active transport, such as root hair cells and gut lining cells often have lots of mitochondria to provide the respiration energy needed.
That's the end of the topic!
Drafted by Joey (Biology)