Membrane Transport Flashcards
Unit 1 Lesson 6
What is Passive Transport?
Movement of molecules without any energy input
What is Diffusion?
The movement of molecules form high to low concentration
What molecules can pass through the membrane with passive transport?
Small non polar molecules, but large charged molecules need the help of intergal proteins.
What affects the rate of Diffusion?
Size: smaller molecules move faster then big one
Charge: neutral molecules move quicker
Concentration Gradient
Distance: harder to move into a large cell
Temp: Higher = Faster
Pressure: High = Quick
What is Osmosis?
The movement of Water molecules for high to low concentration
What does it mean for a cell to be isotonic?
Concentration of solutes outside the cell = to the concentration of solutes inside the cell
no movement of water across the cell membrane, and therefore the cell will neither shrink nor swell
What does it mean for a cell to be hypotonic?
Solution around cell has a lower concentration of solutes compared to inside the cell
causing more water to move into the cell resulting in the cell swelling or potentially bursting if the difference in solute concentration is large enough
What does it mean for a cell to be hypertonic ?
Solution around cell has a higher concentration of solutes compared to the cell’s inside environment, causing water to move out of the cell ,resulting in the cell shrinking;
What is a turgid cell?
A plant cell that is swollen/ firm due to being filled with water
Causing pressure against the cell wall
Making the cell appear inflated and rigid
What is Facilitated Diffusion?
Diffusion involving a carrier or channel protein
Moving form high to low with a bit of help
What is active transport ?
movement of molecules against the concentration gradient with a little help
energy used form the cell
The energy in active transport comes from?
A molecule of ATP
Sometimes an electrical gradient if ions are involved
for example the sodium-potassium pump
What are the 2 forms of MAT
Endocytosis & Exocytosis
What is MAT used for?
Moving large molecules trough the membrane
What are the 3 forms of Endocytosis?
Phagocytosis
Pinocytosis
Receptor-Mediated Endocytosis
What is Phagocytosis?
“cell eating”
membrane goes out and grabs material then pull it inside cell and form a vesicle
What is Pinocytosis?
“cell drinking”
a small vesicle is formed as both fluid and small particles are ingested/ sucked in
What is Receptor-Mediated Endocytosis?
Like Pinocytosis but with receptors
What is Exocytosis?
The reverse of endocytosis -Used when the cell wants to export material
A vesicle containing material produced in the cell fuses with the cell membrane and then lets the material go
