Photosynthesis Flashcards
What does photosynthesis occur in?
Plants and algae
What type of reaction is photosynthesis?
Endothermic reaction as it takes in more energy than it releases
Where is light energy from environment tranferred to?
To the chloroplast in leaves
What’s the equation for photosynthesis?
carbon dioxide+water->glucose+oxygen
What are the symbols for all of them?
Co2, H2O, O2, C6H12O6
What are the three factors that affect rate of photosynthesis?
Temperature, light intensity, carbon dioxide concentration
How does temperature affect ROR?
As temp increases the rate of photosynthesis also increases. As the reaction is controlled by enzymes if the temp increases past a certain point then the enzyme will denature and rate of reaction will decrease
How does light intensity affect the ROR?
The higher the light intensity, the faster the rate of photosynthesis
How does carbon dioxide concentration affect the ROR?
As carbon dioxide is crucial for the process of photosynthesis and to make glucose, if the carbon dioxide concentration increases the rate of reaction also increases
What is a limiting factor?
Something that restricts the rate of photosynthesis or anything else from occurring.
Carry out the experiment of oxygen production so you calculate the rate of photosynthesis?
Put pondweed in a test tube filled with water and seal the top with a bung.
A capillary tube containing water leads into the test tube and is attached to a syringe.
Place a lamp at a measured distance fro, the test tube.
As it photosynthesises, oxygen is produced and a gas tube is formed in the capillary tube.
The distance the bubble has moved is measured using a ruler to calculate the volume of oxygen produced.
Many variable can be changed to observe their affect on photosynthesis like changing temperature (water bath), how long pondweed stays in tube for, and the light intensity also.
It’s also important to control all the factors too that may affect photosynthesis except you independent variable (one you want to observe) so it’s a valid experiment.
What does it mean when a graph involves one limiting factor?
It has one line which levels off, with the factor of the horizontal line and rate of photosynthesis on the vertical axis.
What does it mean when a graph involves two limiting factors?
It has two lines which level off in two experiments. It involves increasing the factor on the horizontal axis and is carried out at two different other environmental conditions, like two different temperatures.
What does it mean when a graph involves three limiting factors?
Same as two limiting factors however another factor is stated on each line, which will be the same in each.
Light intensity is directly proportional to what?
Light intensity is directly proportional to the rate of photosynthesis. This is because the higher the light intensity the more photons hit the chloroplasts in leaves, and more photosynthesis can occur.
What is light intensity inversely proportional to?
Light intensity is inversely proportional to the square of the distance. This is called the INVERSE SQUARE LAW
Light intensity=1/distance^2
What are root hair cells?
They are specialised to take up water by osmosis and mineral ions by active transport from soil to the tips of roots.
What are root hairs cells adaptations?
Have a large surface area to allow more water to move in.
Large permanent vacuole which affects the speed of movement of water from soil to cell.
Mitochondria to provide energy for active transport of mineral ions into root hair cells.
What are xylem cells?
Specialised to take up water and mineral ions from roots to shoots.
What are the adaptations of xylem cells?
A chemical called lignin is deposited which cause the cells to die. This makes them become hollow and joined end to end to form a continuous tube so water and mineral ions can move through.
Lignin is deposited in spirals to withstand the pressure of the water
What are phloem cells?
Specialised to take up the products of photosynthesis to all parts of the plant.
What are the adaptations of phloem cells?
When cell walls die they create structures called sieve plates allowing movement from cell to cell.
Unlike xylem these cells within phloem are alive.
Despite losing many sub cellular structures the energy is supplied by nearby mitochondria of other cells.
These cells use this entertainment to transport sucrose around plant.
