Movement in and out of cells- topic 3 Flashcards
(13 cards)
What is active transport?
Movement of particles from low to high concentration using energy from respiration.
What is a concentration gradient?
A difference in molecule concentration across regions.
What is diffusion?
Net movement of particles from high to low concentration down a gradient.
What does “selectively permeable” mean?
A membrane that allows only some substances to pass through.
What is a turgid cell?
A plant cell full of water with cytoplasm pushing against the cell wall.
What does “flaccid” mean?
A cell that has lost water and become soft.
What is osmosis?
Osmosis is the diffusion of water molecules from a dilute solution (high concentration of water) to a more concentrated solution (low concentration of water) across a selectively permeable membrane.
What affects the rate of diffusion
Temperature, surface area to volume ratio, and concentration gradient.
What is isotonic in osmosis?
When there’s no net movement of water – the solution and the cell have equal concentration.
How can osmosis be tested in tissues?
By measuring mass/length changes in potato slices in sugar/salt solutions.
What makes active transport different from diffusion?
Active transport needs energy and moves particles against the concentration gradient.
What type of molecules move by osmosis?
Only water molecules.
What are examples of active transport?
Glucose into the blood from intestines; mineral ions into root hair cells.
