Photosynthesis and Food Production Flashcards
What is the word equation for photosynthesis
Carbon dioxide + water ( + energy) = Glucose + Oxygen
What is the symbol equation for photosynthesis
6Co2 + 6H20 = C6 H12 O6 + 6O2
Give an organ found in the plant
The leaf
What does photosynthesis do
It converts light energy into chemical energy
Give 4 structures of the leaf and how they are adapted
Leaves are wide and flat to allow a large surface area available to absorb as much light as possible.
Leaves are thin so gasses can reach the cells easily.
Leaves have lots of veins so water can reach all the cells and carry the glucose away.
Leaves have holes called Stomata on their underside to allow gasses in and out.
What are the transparent cells near the top of a leaf called
Transparent Epidermis
What layer is the chloroplast most commonly found in the leaf
Found in the palisade layer, so they’re near the top of the leaf where they can get the most light.
What does the waxy cuticle do and where is it located
On top of the leaf and stops water evaporating away from the leaf, it also acts as barrier to the entry of diseases such as bacteria and fungi.
How would you test a leaf for starch (8)
Place the leaf in a beaker of boiling water using forceps.
Remove and push to the bottom of a boiling tube using a glass rod.
Pour just enough ethanol to cover the leaf.
Place the boiling tube back into the beaker of boiling water.
leave for 5 minuets and the leaf should turn white.
Remove from boiling tube with forceps.
Rinse in water and place on a white petri dish.
Add a few drops of iodine and if it goes black then there is starch.
Why do leafs convert glucose into starch
Because starch is insoluble
Give 3 limiting factors of photosynthesis
Carbon Dioxide
Temperature
light intensity
What is the definition of a limiting factor
Something that slows down the rate of photosynthesis . If this factor is restricted then photosynthesis will be bellow the maximin possible rate.
What happens once there is too much light or carbon dioxide.
The rate of photosynthesis will level off as the rate can’t go any higher without an increase in the other two factors
What happens if there is too much heat for the plant.
The higher the temperature the higher the rate if photosynthesis will occur until the optimum point, when the rate sharply decreases. As the enzymes become denatured
Give a method on how you would find how carbon dioxide affects the rate of photosynthesis.
Place 4 plants of the same size age and type in to 4 test tubes place a rubber band on each of them. Place a lamp of the same brightness over each of them. To each plant give 6 cm² of water in each of the the test tubes. To the first plant, record how many bubbles are released by the plant into the water in two minutes. To the second plant inject 1 cm³ of carbon dioxide. Record the amount bubbles released by the plant, (oxygen). Do this to the other two plants, with 2 cm³ of carbon dioxide to the third plant and 3cm³ of carbon dioxide to the fourth plant. Repeat this experiment again.
