What is diffusion?
The movement of molecules from an area of high concentration to an area of low concentration.
What is osmosis?
The movement of water molecules through a semi-permeable membrane from an area of low solute concentration to high solute concentration.
What is active transport?
The movement of molecules against a concentration gradient, requiring energy (ATP).
What is facilitated diffusion?
Movement of molecules across a membrane with the help of transport proteins, without energy.
What are the key differences between passive transport and active transport?
Passive transport does not require energy and moves molecules with the concentration gradient. Active transport requires energy and moves molecules against the gradient.
What is a concentration gradient?
The difference in the concentration of a substance between two areas.
What is an isotonic solution?
An isotonic solution has the same concentration of solutes as the inside of the cell, causing no net water movement.
What happens to a cell in a hypotonic solution?
Water enters the cell, causing it to swell and potentially burst (lysis).
What happens to a cell in a hypertonic solution?
Water leaves the cell, causing it to shrink (crenation).
What is the effect of an isotonic solution on a cell?
The cell retains its normal shape because there is no net water movement.
How does osmosis differ from diffusion?
Osmosis specifically refers to the movement of water molecules, while diffusion can refer to any molecules.
What is the role of protein channels in cell membranes?
Protein channels help specific molecules cross the cell membrane in processes like facilitated diffusion and active transport.
What type of transport does not require energy?
Passive transport (diffusion, osmosis, facilitated diffusion).
How does active transport differ from facilitated diffusion?
Active transport requires energy to move molecules against the concentration gradient, while facilitated diffusion does not require energy and moves molecules with the gradient.
What is endocytosis?
A process by which a cell engulfs material from the outside environment into the cell via vesicles.
What is exocytosis?
A process by which materials are expelled from the cell via vesicles.
What happens to a plant cell in a hypotonic solution?
The cell becomes turgid due to water entering, but the cell wall prevents bursting.
What happens to a plant cell in a hypertonic solution?
The plant cell undergoes plasmolysis, where the cell membrane pulls away from the cell wall due to water loss.
What is the function of aquaporins in cell membranes?
Aquaporins are channels that specifically facilitate the movement of water across the cell membrane.
Why is osmosis important to cells?
Osmosis helps maintain the proper balance of water within cells, which is crucial for cell function and homeostasis.
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