Movement of Substances Flashcards
Define diffusion.
Movement of molecules from a high to a low concentration.
What is osmosis?
Movement of water across a semi-permeable membrane from high to low water concentration.
What is active transport?
Movement of substances against a concentration gradient using energy from respiration.
Give an example of diffusion in humans.
Gas exchange in the lungs (oxygen and carbon dioxide).
How do root hair cells use active transport?
To absorb minerals from the soil.
What is a concentration gradient?
A difference in concentration between two areas.
Why does active transport require energy?
It moves substances against their concentration gradient.
What is turgor pressure in plant cells?
Pressure exerted by water inside the vacuole against the cell wall.
How does osmosis help plants stay upright?
Water moves into cells, keeping them turgid.
How do animals use diffusion to obtain energy?
Glucose and oxygen diffuse into cells for respiration.
