Movement Of Substances Flashcards
What is diffusion?
The movement of substances from an area of high concentration to low concentration until a state of equilibrium is reached.
What is active transport?
The movement of substances across a concentration gradient using energy from respiration
What is osmosis?
The movement of water molecules from an area of high concentration to an area of low concentration.
Osmosis takes place across a partially permeable membrane until a state of equilibrium is reached.
What is water potential?
The ability of water molecule to move freely.
How is the rate of diffusion increased?
A steep concentration gradient
High temperatures
A large surface area to volume ratio
What is the concentration gradient?
The difference between the concentration of substances in different areas
What is turgid?
When a plant cell absorbs water and develops an internal pressure
The vacuole swells and pushes against the cell wall
What is the term given to a plant cell that has absorbed lots of water by osmosis?
Turgid
What is flaccid?
When a plant cell loses water
The vacuole shrinks
The cell loses shape
Why do unicellular organisms not have a circulatory system?
Because their surface areas to volume ratio is high.
Their cell surface membrane has a large enough area to supply all the oxygen (by diffusion) that their volume demands
Why do multicellular organisms have circulatory systems?
Because the surface area to volume ratio is lower than that of unicellular organisms
Special gas exchange organs and circulatory systems have evolved to ensure effective gas exchange
What term is given to the water potential of a dilute solution?
Hypotonic: low concentration of solute
HIGH water potential
What term is given to the water potential of a concentrated solution?
Hypertonic: Hugh concentration of solute
LOW water potential
What term is given to the water potential of a solution with equal concentration of solute?
Isotonic
reached the state of equilibrium
