Topic 6 Flashcards
(18 cards)
What is photosynthesis?
Photosynthesis is the process where plants are able to make complex carbohydrates using the energy from light
What is the word equation for photosynthesis?
Carbon dioxide + Water → Glucose + Oxygen
What is the symbol equation for photosynthesis?
6CO2 + 6H2O → C6H12O6 + 6O2
What is chlorophyll used for in photosynthesis?
Chlorophyll is used to absorb light energy and transfer it into chemical energy so that it can be used to build complex organic molecules (e.g. glucose).
What are the five uses of glucose made by the plant?
Respiration, stored as starch, coverted to sucrose, making cellulose, making nectar
How can the importance of chlorophyll in photosynthesis be shown experimentally?
Find a leaf that has green parts and non-green parts
Keep the plant in the dark for 2 days and then test both the green and non-green parts for starch
Move the plant into sunlight and then wait another 2 days and test both parts of the plant again
The green parts contain chlorophyll and these should be the only ones testing positive for starch in the second test
How can the importance of light in photosynthesis be shown experimentally?
Put a plant in the dark for 48 hours
Remove the plant and place a strip of opaque tape over part of a leaf
Leave the plant in the sun for 48 hours
Remove the tape and test the part of the plant that did not have the tape on and also the part that did have the tape on for starch and compare the results
The uncovered section should be the only one that tests positive for starch
How can the importance of CO2 in photosynthesis be shown experimentally?
Place transparent plastic bags over 2 separate plants
Place sodium hydrogencarbonate inside the bag of one (produces CO2)
Place soda lime in the other (absorbs CO2)
Test the plant leaves for starch a day later
What is a limiting factor?
A factor that limits the rate of a reaction when there is not enough of it
When may light be a limiting factor for photosynthesis?
In a dense forest or at night
When may temperature be a limiting factor for photosynthesis?
In winter
How can hydrogencarbonate indicator be used to investigate what happens to plants in the dark?
Cover one plant’s leaves with tin foil, keep another exposed to the light
Place each plant in a boiling tube containing hydrogencarbonate indicator and set up another tube containing hydrogencarbonate indicator only as a control
The test tube with the tin foil covered plant will have yellow coloured indicator due to CO2 from respiration
The test tube with the uncovered plant will have purple indicator as the carbon dioxide will have been removed by photosynthesis
The control will remain red
What are nitrate ions used for in plants?
They are used in the synthesis of amino acids
What are magnesium ions used for in plants?
They are used to make chlorophyll
How is the spongy mesophyll layer adapted for photosynthesis?
It is packed loosely which allows gases to diffuse through the plant for photosynthesis (CO2 in, O2 out)
How is the palisade mesophyll layer adapted for photosynthesis?
It contains long and thin cells with many chloroplasts and lots of chlorophyll to carry out photosynthesis
What is the importance of the vascular bundles in photosynthesis?
The xylem is adapted to transport water which is useful to provide the cells with a constant supply of water for photosynthesis
The phloem is adapted to transport sugars to where they are needed from the photosynthesising tissues that produce them
How are the guard cells adapted to aid the process of photosynthesis?
Guard cells can change shape to open or close pores in the leaf which controls the exchange of gases needed for photosynthesis
