Active Transport Flashcards
Active transport =
Low to high
What is an example of active transport?
The Sodium Potassium Pump. The sodium is sent outside and the potassium is sent inside using the same channel. The aim is to create a concentration gradient i.e. high concentration of sodium outside the cell, the sodium is used as a co-transport molecule for glucose uptake.
What is active transport?
Active transport allows the cell to take up a substance against the concentration gradient. It uses selection protein carrier molecule, the protein is intrinsic and the molecule will bond with the protein when they come into contact, they are complementary. The bond makes the protein change its shape, after the molecule leaves the protein, the protein will change back to its original shape.
What will there be in cells where a lot of active transport occurs?
Cells where a lot of active transport occurs e.g. in epithelial cells in the small intestine, will have many mitochondrion for the production of ATP.
Does it require ATP?
Yes it requires ATP, ATP binds to the protein inside and is broken down: ATP ➡️ ADP + Pi, this causes the protein to change shape.
What is the rate of active transport effected by?
- the number of proteins available
- the effectiveness of the proteins
- the availability of ATP from the mitochondria
What do the villi and micro villi do?
They are finger like projections in the small intestine which absorb nutrients.
What is the sodium glucose co-transport system?
Glucose is absorbed from the small intestine via facilitated diffusion. It uses carrier molecules called co-transport proteins in the CSM of the empirical cells. The glucose is bought in with the sodium ion that is coming down the the concentration gradient, it occurs in the ileum. The protein carriers only transport glucose in the presence of sodium ions. Sodium is actively transported out of the cell into the blood to lower the concentration of sodium compared to the ileum by the NaK Pump. As a concentration gradient has been achieved the sodium diffuses back through the carrier proteins and a glucose molecule is transported into the cell. The glucose molecules pass from the cells into the blood by facilitated diffusion of another carrier.
Summary of active transport?
Example of molecule transported by it is sodium, it occurs against the concentration gradient, it only occurs in one direction, it requires proteins in the membrane and ATP.
What does endocytosis and exocytosis do?
Removes enzymes and waste products, it occurs in both direction and requires ATP.
