Facilitated Diffusion Flashcards
What is facilitated diffusion?
Diffusion that uses transport proteins to move molecules across a membrane.
Is facilitated diffusion a mode of passive transport?
Yes.
How does facilitated diffusion work?
Transport proteins act like doors, allowing molecules to pass through the plasma membrane and diffuse as they usually would-this is facilitated diffusion. This is all done without the use of ATP, it is a mode of passive transport.
What is passive transport?
A form of cell transport that does not require energy in the form of ATP.
What are transport proteins?
Proteins in the cell membrane that move molecules across the membrane.
What is active transport?
Cell transport that uses energy in the form of ATP.
What happens during active transport?
You’re moving against the concentration gradient, which means you’re moving from an area of low concentration to an area of high concentration. Since it is moving against what is natural, it’s going to require energy from the cell to push it in that direction.
What do sodium potassium pumps do?
They move sodium from an area of low concentration (inside the cell) to high concentration (outside the cell), potassium from low concentration (outside the cell) to high concentration (inside the cell) and making the cell negatively charged: -3NA+ out of the cell(-3) plus 2k+ (+2).
The above readies nerve and muscle cells for an action potential.
What is Endocytosis?
A type of active transport that moves larger particles through the cell membrane that would not be able to get through on their own. Endocytosis moves particles into the cell.
What is Exocytosis?
A type of active transport that moves larger particles through the cell membrane that would not be able to get through on their own. Exocytosis moves particles out of the cell.
How does Endocytosis work?
The cell membrane will start to form a vesicle. That vesicle will then pinch off and move those particles into the cell. It’s a means of moving larger particles into the cell.
How does Exocytosis work?
A vesicle moves towards the plasma membrane, attaching to it, and then expelling whatever the contents are out of the cell. It’s a means of moving larger particles out of the cell.
What is the difference between Endocytosis and Exocytosis?
Endocytosis moves particles in, and Exocytosis moves things out.
