Plants Flashcards
Word 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 an endothermic reaction?
Photosynthesis takes in light energy, so products of the reaction contain more energy than the reactants
Glucose?
Used for respiration
Starch?
Stored in plant cells or broken down into sucrose for transport around the plant
Sucrose?
Soluble sugar transported in phloem via translocation
What causes stomata to open and close?
Water flows in guard cells and they become turgid and open or flaccid when they don’t have water and close
Leaf adaptations to photosynthesis?
Large surface area, palisade layer at the top of the leaf, lots of chloroplasts
A limiting factor of photosynthesis?
Temperature, light intensity, carbon dioxide
What happens when the temperature is too high?
Enzymes are denatured
What do roots do?
Absorb water and mineral ions
How does water travel into the roots?
Osmosis through cytoplasm and by diffusion through cell walls
What does xylem transport?
Water and mineral ions
Structure of xylem vessels?
No cytoplasm to increase area water can flow through
What does phloem transport?
Sugars-sucrose
How are root hair cells adapted?
Large surface area, thin cell walls
Diffusion and osmosis?
Down concentration gradient and requires no energy
Active transport?
Against concentration gradient and requires energy
Transpiration?
Movement of water from roots, up xylem leaves where it evaporates through stomata
Translocation?
Transport of sugars from leaves around the plant in the phloem
How do plants adapt to hot environments?
No leaves to reduce water loss
Diffusion?
Down a concentration gradient. From high to low concentration
Osmosis?
Movement of water particles through a partially permeable membrane from an area of high concentration to low concentration of water
Affect of increasing light intensity?
Increasing light intensity increases rate of photosynthesis until it levels off due to a limiting factor
Companion cells?
Next to phloem vessel with small pores. Contain mitochondria to provide energy for active transport
How does light intensity affect rate of transpiration?
Light intensity- increases rate- stomata open wider(allows CO2 in and water out)
How does wind speed affect transpiration?
Wind speed- increase transpiration- water is moved away from stomata quicker
Temperature increase affect on transpiration?
Temperature increase- increases transpiration- increased diffusion/evaporation
Humidity increase affect on transpiration?
Humidity increase- decreases transpiration- more water around leaf affects concentration gradient
Xylem adaptations?
Cells are dead, no cytoplasm, leaving space to transport water and minerals. Top and bottom cell walls are gone but side walls stay and have lignin to keep it solid so it can withstand water pressure
Adaptations of phloem?
Siege cell has little cytoplasm and no nucleus, this makes more space to transport sucrose.
Companion cells have lots of mitochondria to help release energy for active transport
Differences between xylem and phloem?
Xylem- dead, empty, lignin in walls, transport water and minerals
Phloem- alive, companion cells have nucleus, vacuole and mitochondria, active transport, transports sugars
Affects photosynthesis?
Chlorophyll, water, carbon dioxide, sunlight
How much carbon dioxide affect on photosynthesis?
Increasing photosynthesis with increasing % of CO2 until limiting factor stops increase
Temperature affect on photosynthesis?
As temp increases, so does photosynthesis, until it reaches optimal temp, then after enzymes are denatured
Light intensity affect on photosynthesis?
No photosynthesis in the dark. Then increases as intensity increases until limiting factors stop the increase.
Cuticle?
Waxy layer on leaf
Upper epidermis?
Covers plant
Palisade mesophyll?
Where photosynthesis happens
Spongy mesophyll?
Space for gas exchange
Lower epidemis?
Covers plant
Guard cells?
Open and close to allow transpiration
