Plants Flashcards
What is the equation for photosynthesis?
Carbon dioxide + water -> glucose + oxygen
Where does photosynthesis take place?
Chloroplasts
What is an ‘endothermic reaction’ ?
A reaction that takes in energy.
Why is photosynthesis a endothermic reaction?
Photosynthesis takes in light energy.
What is glucose used for in a plant?
Used for respiration.
What is starch used for in a plant?
Stored in plant cells or broken down into sucrose for transport around plant.
What is sucrose used for in plants?
Soluble sugar transported in phloem via translocation.
Ways leafs are adapted for photosynthesis?
Large surface area
Palisade layer at top of the leaf
Lots of chloroplasts
What is a limiting factor?
A factor that limits the rate of photosynthesis.
Examples of limiting factors?
Temperature
Light intensity
Carbon dioxide
What does increasing light intensity do?
Increases rate of photosynthesis.
What is the effect of temperature on photosynthesis?
As temp increases enzymes have more energy and more collisions happen which increases rate of photosynthesis BUT when temp is too high the enzymes are denatured.
What would happen to the light intensity if you doubled the distance from the light?
Would quarter the light intensity.
What do roots do?
Absorb water and mineral ions.
How does water travel into the root?
Enters by osmosis through the cytoplasm and by diffusion through the cell walls.
What is transpiration?
Movement of water from roots up xylem to leaves where it evaporates through stomata (one way movement)
What is translocation?
Transport of sugars from leaves around the plant in the phloem (2 way movement)
What does xylem transport?
Water and mineral ions
What is the structure of xylem vessel?
No cytoplasm to increase area water can flow through
Thick walls so water pressure doesn’t burst the cells
What does phloem transport?
Sugars - sucrose
In what ways are root hair cells well adapted for their job?
Large surface area
Thin cell walls
What are and what do sieve cells do?
Part of phloem vessels and contain pores for transfer of molecules through phloem.
No nucleus and very little cytoplasm to create a wide channel.
How are plants adapted to hot environments?
No leaves to reduce the water loss
Stomata will only open at night to reduce water loss as it’s cooler , so less water will leave the stomata.
Factors that effect rate of transpiration are…
Light intensity
Wind speed
Temperature increase
Humidity increase
What are companion cells?
Next to phloem vessel with small pores. Contain many mitochondria to provide energy for active transport.
Diffusion is ….. concentration gradient.
Down
Osmosis is …. concentration gradient.
Down
Active transport is …. concentration gradient.
Against
Does diffusion require energy?
No
Does osmosis require energy?
No
Does active transport require energy?
Yes
