Please enable JavaScript.
Coggle requires JavaScript to display documents.
Movement In and Out of Cells - Coggle Diagram
Movement In and Out of Cells
Diffusion
particles have more kinetic energy at higher temperatures
more kinetic energy = faster movement
happens when molecules move randomly and spread fairly evenly across the room
high concentration = lot of molecules
DEFINITION: the net movement of particles from an area of high concentration down a concentration gradient due to the random movement of particles
Diffusion in Living Organisms
also important for gas exchange for repiration in animals and plants
cell membranes are freely permeable to oxygen and carbon dioxide
particles are free to move in the cytoplasm so they diffuse, spreading to all parts of the cytoplasm
Osmosis
DEFINITION: the net movement of water molecules from a region of high water potential (dilute solution) to a region of low water potential (concentrated solution) through a partially permeable membrane
Water potential and osmosis affect how and when organisms take up and lose water
Osmosis and Animal Cells
Cell membranes are partially permeable
They let water through easily, but other molecules and ions often cannot
Osmosis takes place across cell membranes
Pure Water
Osmosis takes place and water enters the cell through the partially permeable membrane
If an animal cell is placed in
PURE WATER
the water
ENTERS
the cell and the cell
SWELLS
and
BURSTS
Concentrated Solution
Osmosis takes place and water diffuses out of the cell through the partially permeable membrane
If an animal cell is placed in a
CONCENTRATED
solution, the water
LEAVES
the cell and the cell
SHRINKS
Osmosis and Plant Cells
Plant cells have fully permeable membrane
Pure Water
water ENTERS the cell by osmosis. The cell SWELLS but does not burst (strong cell wall)
the cytoplasm presses out against the cell wall, but the wall resists and presses back on the contents
the pressure of the water pushing outwards keeps the cell strong and firm (supports the plant leaves). This is
turgor
pressure
turgid
: plant that is tight and firm
Concentrated Solution
water moves out, the cytoplasm and vacuole shrink and pull away from the cell wall
the contents do not push out on the cell anymore so it becomes FLACCID
plant loses firmness and begins to wilt
flaccid: plant cell that is soft
Active Transport
aerobic respiration in mitochondria, releases energy for the cell to use. some of this energy is used for active transport
definition: movement of molecules or ions through a cell membrane from a region of lower concentration to higher concentration using energy from respiration
PROCESS
1) nitrate ion enters the carrier protein
2) the carrier protein changes shape. The energy needed for it to do this is provided by respiration in the cell
3) the change of shape of the carrier protein pushes the nitrate ion into the cell