Active Transport Flashcards
Homeostasis
In order to survive, organisms must keep their internal environments relatively constant, and different from its external environment
Active transport is necessary to
Import and export ions that are different concentrations inside and outside of the cell
Active transport definition
The movement of molecules from a low concentration to a high concentration across a cell membrane, using ATP and a carrier protein
Cells that actively transport a lot
Have high numbers of mitochondria to provide ATP
What causes active transport to cease
- cyanide
- lack of oxygen
- respiratory inhibitors
• no ATP can be produced
Carrier protein types
- uniport carrièrs -> move a single substance in a single direction
- symport carriers -> move two substances in the same direction
- antiport carriers -> move two substances in opposite directions
Describe the graph for rate of glucose uptake by ileum cells (y-axis) against O2 concentration (x-axis)
As O2 conc. increases, rate of glucose uptake increases (due to higher rate of respiration caused by creased O2 conc causing higher rate of ATP production, so more ATP is available for active transport).
Levels off when carrier proteins become the limiting factor as they are working at maximum capacity; increasing O2 conc. further has no effect
Describe the graph of rate of glucose uptake by ileum cells (y-axis) against time (min), when cyanide is added at a certain point
Rate is constant until cyanide is added, when rate dramatically decreases, then levels off.
Cyanide inhibits respiration, inhibiting production of ATP and therefore glucose cannot be taken up by active transport
Co-transport
Form of active transport in which the pumping of one substance down its concentration gradient indirectly drives the transport of one or more other substances against conc. gradient
