Chapter 3 Flashcards
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 energy for diffusion come from?
energy for diffusion comes from the kinetic energy of random movement of molecules and ions
Use of diffusion
- obtain many of their requirements
- get rid of many of their waste products
- carry out gas exchange for respiration
Factors that’s effect diffusion
Surface area, temperature, concentration gradient and distance
Describe osmosis
the 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
Osmosis Experiment
Potato in distill water increase mass, increased turgor pressure making it turgid.
potato in strongest sucrose solution less mass, plasmolyse (meaning the cell membrane has pulled away from the cell wall)
Explain the importance of water potential and osmosis in the uptake and loss of water by organisms
Plants obtain water by osmosis through their roots.The water acts as a transport medium for minerals and nitrate ions and maintains the turgidity of the cell.
Animals If the water would only diffuse out or into the cell, it would shrink or burst.Nutrients and minerals are diffused along with the water.
How are plants supported
They are supported by the pressure of water inside the cells pressing outwards on the cell wall
Define active transport
as the movement of particles through a cell membrane from a region of lower concentration to a region of higher concentration (i.e. against a concentration gradient), using energy from respiration
Importances of active transport
a process for movement of molecules or ions across membranes, including ion uptake by root hairs
What happens to protein carriers during active transport?
protein carriers move molecules or ions across a membrane during active transport
