Osmosis Flashcards
Give four uses of water in plants
Cooling
Transport
Photosynthesis
Turgor/support
Define Osmosis
Osmosis is the diffusion of water from a high water concentration to a low water concentration through a semi-permeable membrane
How do you calculate percentage change in sucrose concentration?
(Change ,divided by, Initial) X 100
Describe and explain the effect of temperature on the process of transpiration.
High temperature increases rate of transpiration as the diffusion gradient is greater as there is less water outside than inside the plant cell.
In many plants, the stomata close in very hot weather. Give one disadvantages and one advantage of this to the plant.
Advantage - reducing loss in water through evaporation
Disadvantage - no photosynthesis
Describe the process of transpiration
Transpiration is the evaporation of water from spongy mesophyll cells, followed by diffusion through air spaces and then through the stomata
Leaf surface area also affects transpiration rate. Describe and Explain the relationship between leaf surface area and rate of transpiration.
The larger size of the leaf surface means larger amount of stomata, more stomata means more stomata for water to evaporate from meaning higher rate of transpiration
Describe and explain how increasing light intensity affects the rate of water uptake in plants
More water uptake
More photosynthesis with more light
More water needed or used for photosynthesis
What is transpiration
Transpiration is the evaporation of water from aerial parts of the plant
Describe and explain how water moves from the xylem out to the atmosphere
Water moves by osmosis from the xylem to the spongy mesophyll cells
Water evaporates from the surface of the spongy mesophyll cells to the air spaces
Water vapour diffuses from the air space through the stomata into the atmosphere
Factors which increase the rate of transpiration ( 4 Terms )
High temperature
High light intensity
High wind speed
Low humidity
Factors which decrease the rate of transpiration (4 terms)
Low temperature
Low light intensity
Low wind speed
High humidity ( clear plastic bag )
Describe the process of plasmolysis ( 5 Points )
When a plant cell is places in a strong sugar
Explain what happens when a red blood cell is placed in water
Water absorbed by cell by diffusion from a high water concentration to a low through the process of osmosis through a semi permeable membrane which causes lysis ( swell and burst )
What happens when a plant cell is placed in water
Water moves into the cell through osmosis through a semi permeable membrane however does not burst as the cell membrane resist outward force causing it to push against the cell wall stopping water intake and becoming turgid
