Transport Across Membranes (LC 2027) (Leaving Cert Biology): Flashcards
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Practise the cards
15 cards from this deck
What is diffusion?
What is diffusion?
Molecules spread from high to low concentration naturally
Direction of diffusion
Direction of diffusion
From high to low concentration (down gradient)
Does diffusion require energy?
Does diffusion require energy?
No - it's a passive process
What is osmosis?
What is osmosis?
Diffusion of water across selectively permeable membrane
Direction of water movement in osmosis
Direction of water movement in osmosis
From high to low water concentration
What does selectively permeable mean?
What does selectively permeable mean?
Allows some substances through, blocks others
Effect of isotonic solution on cell
Effect of isotonic solution on cell
No change - same concentration as cytoplasm
Hypotonic solution effect on animal cell
Hypotonic solution effect on animal cell
Cell swells, may burst (water enters)
Hypertonic solution effect on animal cell
Hypertonic solution effect on animal cell
Cell shrinks and becomes crenated (water leaves)
What is a turgid plant cell?
What is a turgid plant cell?
Swollen and firm from water entering
What is plasmolysis?
What is plasmolysis?
Cytoplasm shrinks and pulls away from cell wall
Does active transport require energy?
Does active transport require energy?
Yes - requires ATP energy
Direction of active transport
Direction of active transport
Against concentration gradient (low to high)
How salt preserves food (osmosis)
How salt preserves food (osmosis)
Creates hypertonic environment, dehydrates bacteria
Active transport in root hair cells
Active transport in root hair cells
Absorbs minerals even when soil concentration is lower