Facilitated Diffusion 2.7 Flashcards
How do charged molecules or ions pass through the membrane?
Through gated ion channels
How do large polar molecules pass through the membrane?
Through channel/carrier proteins (pumps), endocytosis, or exocytosis.
How do small amounts of water pass through the membrane?
osmosis
How do large amounts of water pass through the membrane?
aquaporins
How do the passage of ions affect the membrane potential?
Ions into the cell make the potential raise, while ions moving out of the cell lower the membrane potential.
What is required for active transport?
ATP or an electrochemical gradient created by nearby channel (ex: neuron).
How is a concentration gradient established and maintained?
By active transport pumps
What is the function of an ATPase?
It pumps Na and K across the membrane, which creates membrane potential.
How does the Na + /K +ATPase maintain the membrane potential?
It consistently pumps K into the cell and Na out, meaning the membrane potential will rest at -70mv (neurons)
