Movement in and out of cells

• The higher the temperature, the faster ions, atoms, and molecules move.
• Living organisms obtain many of their requirements through diffusion.
• Living organisms get rid of many of their waste products through diffusion.
• Carbon dioxide diffuses from the air into the leaves of plants, through the stomata. This is because there is a lower concentration of CO2 in the leaf, as the cells are using it up. In the air, there is a higher concentration, therefore molecules diffuse into the leaf.
• Diffusion moves from a high to low concentration gradient.
• Oxygen is a waste product of photosynthesis and diffuses out of the plant through the stomata.
• Diffusion is important in gas exchange for respiration in animals and plants.
• The cell membrane is fully permeable to oxygen and carbon dioxide, so they can diffuse easily in and out of cells.
• Water can make up to 80% of some organism's bodies.
• Water has many different functions, including acting as a solvent for many different substances.
• Substances are transported around the body dissolved in the water in blood plasma.
• Visking tubing is a partially permeable membrane. During osmosis, it lets water pass through pores, but not sugar because sugar molecules are too large.
• Only water molecules will be able to pass through the partially permeable membrane. Movement of water molecules will even out the concentration of sugar.

  
• Dilute Solution: Has a high water potential
• Concentrated Solution: Has a low water potential
• Water molecules in osmosis move from a high to low concentration.
• Inside large animals, cells are surrounded by tissue fluid.
• In the soil, the roots of plants are often surrounded by a film of water.
• Cell membranes separate the cytoplasm from the outsides of the cell. If the solutions have different concentrations, osmosis will occur.
• Water molecules diffuse from the dilute to the concentrated solution, however as more and more water enters the cell, it could burst.
• As molecules diffuse out of the cell, the cytoplasm shrinks and the cell shrivels up.
• Plant cells do not burst in pure water. Plant cells are surrounded by a cell wall meaning that it will let any molecules go through it.
• Plant cells also have a partially permeable membrane, so it will take in water through osmosis and as the water goes in the cytoplasm and vacuole will swell.
• Plant cells have a cell wall surrounding it and it will stop the plant cell from bursting with water. The cytoplasm presses against the wall, but the cell wall resists and presses back.
• When a plant cell is swelling with water but isn't bursting due to the cell wall, it is said to be turgid.
• The pressure of the cytoplasm on the cell wall is called turgor pressure.
• The turgidity of its cells helps the plant to stay upright and keeps the leaves firm. Plant cells are usually turgid.
• When cells lose water due to osmosis, the cytoplasm shrinks and the cell becomes floppy, also known as flaccid.
• When plant cells become flaccid, they lose their firmness and begint o wilt.
• If an outside solution is very concentrated the cytoplasm and vacuole in a plant will continue to shrink, but since the cell wall is very firm, it will get left behind.
• If a cell membrane gets left behind during osmosis, the cell becomes plasmolysed.
• Plasmolysis isn't very common as cells aren't usually surrounded by high concentrated solutions, however if it does occur the plant will die because the cell membrane is damaged as it is teared away from the cell.