B8: Photosynthesis Flashcards
Where is the chloroplasts situated?
In the leaf
Where is chlolorphll
Pigment inside
What does photosythesis allow?
Plants to create their own food
Where and when does photosythesis occur?
In the green parts of plants(chloroplasts which contain a green substance called chlorophyll)when there is light
How is energy transferred during photosythesis.
Energy is transferred from the envriroment to the chloroplasts by light
What is the energy used for?
To convert carbon dioxide and Water to glucose(a simple sugar) -oxygen is a by product
What type of reaction is photosythesis?
Endothermic reaction
What do endothermic reactions need?
An input of energy from the enviroment
What is the word equation for photosythesis?
Carbon dioxide + water-light-glucose+ oxygen
What is the symbol equation for photosytheis?
6CO2 + 6H2O-light- C6H12O6+6O2
How can we tell if water molecules are being produced
Air bubbles
What are 6 adaptations of the leaves for photosythesis?(so a plant can photosythesise as much as possible
- leaves are broad(bigger SA for light)
- leafes are thin(diffusion for gases are short)
- they contain chlorophyll in the chloroplasts to absorb light
- veins-water from the xylem
- air spaces allow CO2 to get into cells and oxygen to leave by diffusion
- guard cells open and close to regulate gas exchange
What are 3 possible limiting factors of photosythesis?
- light(intensity)
- temperature(photosytheis is controlled by emzymes)
- carbon dioxide concentration(needed for photosythesis)
When can a plant not make enough chlorphyll?
When it does not have enough minerals (esspecially magnesium)
What does the inverse square law state?
As tne distance of light from the plant increases, the light intensity decreases
Light intensity= 1/distance squared
What is the reverse of photosythesis?
Respiration
Startch is ____ in water
Insoluble
What is needed for plants to grow as fast as possible?
- warm enviroment
- plenty of light
- CO2
- water
How manipulate the enviroment for plants?
Garden greenhouse
How dpes a greenhouse affect the rate of photosythesis?
-the glass means the enviroment is much more controlled than in a feild
it increases the rate of photosythesis and allows us to plant crops that wouldn’t grow well pousidd
Why is controlling everything important?
-it prevents natural limiting factors from the time of day(temperature, light ect)
What is the name of the system that allows all limiting factors to be controlled?
Hydroponics
Is keeping the conditions in greenhouses just right expensive?
Yes but less staff are needed and there a greater number of crops and the crops are cleaner(profit)
Which chemical in the leaves is required for photosynthesis?
Chlorophyll
In which cell organelle do the reactions of photosynthesis take place?
Chloroplast
In which layer of the leaf does the most photosynthesis take place?
Palisade layer
The diagram shows the experimental setup to investigate the effect of light intensity on the rate of photosynthesis.
What is the function of the beaker of water?
Acts as a heat shield
Why does temperature increase the rate of photosynthesis (up to a certain point)?
As temperature increases the rate of enzyme activity also increases.
Look at the diagram. On focus eLearning you completed this practical to investigate the effect of light intensity on the rate of photosynthesis.
Identify the independent variable in this investigation.
Distance the lamp is from the plant
Look at the diagram. On focus eLearning you completed this practical to investigate the effect of light intensity on the rate of photosynthesis.
Identify two control variables in this investigation.
- volume of water in the test tube
- concentration of carbon dioxide
The graph shows the effect of temperature on the rate of photosynthesis.
Explain why the the graph decreases to a rate of zero.
The enzymes have become denatured and can not longer catalyse the reactions.
Point B on the graph is called the compensation point. This indicates where…
The rate of photosynthesis is equal to the rate of respiration.
What type of reaction is phototythesis”
Endothermic
