Movement into and out of cells Flashcards
What is diffusion?
the net movement of particles from a region of their higher concentration to a region of their lower
concentration as a result of their random movement
Where does the energy for diffusion come from?
the energy for diffusion comes from the kinetic energy of random movement of molecules and ions
How does diffusion occur in the body?
some substances move into and out of cells by diffusion through the cell membrane
Describe the importance of diffusion of gases and
solutes in living organisms?
The diffusion of gases and solutes is important as without it, molecules which are needed for life, for example, glucose and oxygen for respiration, would not be able to get to the places they are needed.
Investigate the factors that influence diffusion?
Concentration gradient
Temperature
Surface area
Distance
What is osmosis?
Net movement of water molecules from a region of
higher water potential (dilute solution) to a region of lower water potential (concentrated solution) through a partially permeable membrane
Describe the role of water as a solvent in organisms?
The role of water as a solvent in organisms to aid with digestion, excretion and transport
How does the concentration affect osmosis?
Conc. of solute outside cell = conc. inside cell → no change in size
Conc. of solute outside cell > conc. inside cell → cell shrinks (Flaccid/Plasmolysis)
Conc. of solute outside cell < conc. inside cell → cell swells (Turgid)
What is active transport?
the movement of particles through a cell membrane from a region of lower concentration to a region of higher
concentration using energy from respiration
Explain the importance of active transport?
Active transport is needed when an organism wants to optimize the nutrients it can take up. E.g ion uptake by root hairs cell.
What do protein carriers do?
move molecules or ions across a membrane during active transport
