Photosynthesis Investigation and Light
LIGHT IN PHOTOSYNTHESIS
Theory:
Leaf discs float normally. When the air spaces are infiltrated with the solution the overall density of the leaf disc increases and the disc sinks. The infiltration solution includes a small amount of sodium bicarbonate. The bicarbonate ions serve as the carbon source for photosynthesis. As photosynthesis proceeds oxygen is released into the interior of the leaf which changes the buoyancy – causing the discs to rise. Since cellular respiration is taking place at the same time, consuming oxygen, the rate of which the discs rise is an indirect measurement of the net rate of photosynthesis.
Aim:
To find out if light affects the rate of photosynthesis through an investigation with leaf discs of a spinach leaf.
Hypothesis:
If the light source is removed or becomes limited, then it will take much longer for the leaf disc to rise as cellular respiration will no longer be taking place as part of the equation for photosynthesis will be missing; light. Indirectly, this means that the rate of which the discs rise will take longer.
Materials:
3 Leaves
Hole punch
Lamp
Diluted soap (one drop) x2
1 X 1 metre Aluminium foil x2
1 X 1 metre Glad wrap x2
300mL water x2
1g of sodium bicarbonate x2
Plastic syringe (10cc or larger)
Stopwatch
Small beaker x2
Variables:
Dependent variable: Spinach leaf disks as it is changed by not only the bicarbonate soda but also possibly light and many other factors.
Independent variable: Time as we are measuring how long the photosynthesis will take to make the leaves rise. Time is also not influenced by any other factors.
Method:
1. Prepare a solution: using scales, measure 1 gram of sodium bicarbonate. Then, using a measuring cylinder, measure 300ml of water. Place both materials into a beaker
2. Add 1 drop of dilute liquid soap to this solution.
3. Using a hole punch, cut 10 uniform leaf discs for each trial. Be careful to not cut yourself in this process. Do not use a
Theory:
Leaf discs float normally. When the air spaces are infiltrated with the solution the overall density of the leaf disc increases and the disc sinks. The infiltration solution includes a small amount of sodium bicarbonate. The bicarbonate ions serve as the carbon source for photosynthesis. As photosynthesis proceeds oxygen is released into the interior of the leaf which changes the buoyancy – causing the discs to rise. Since cellular respiration is taking place at the same time, consuming oxygen, the rate of which the discs rise is an indirect measurement of the net rate of photosynthesis.
Aim:
To find out if light affects the rate of photosynthesis through an investigation with leaf discs of a spinach leaf.
Hypothesis:
If the light source is removed or becomes limited, then it will take much longer for the leaf disc to rise as cellular respiration will no longer be taking place as part of the equation for photosynthesis will be missing; light. Indirectly, this means that the rate of which the discs rise will take longer.
Materials:
3 Leaves
Hole punch
Lamp
Diluted soap (one drop) x2
1 X 1 metre Aluminium foil x2
1 X 1 metre Glad wrap x2
300mL water x2
1g of sodium bicarbonate x2
Plastic syringe (10cc or larger)
Stopwatch
Small beaker x2
Variables:
Dependent variable: Spinach leaf disks as it is changed by not only the bicarbonate soda but also possibly light and many other factors.
Independent variable: Time as we are measuring how long the photosynthesis will take to make the leaves rise. Time is also not influenced by any other factors.
Method:
1. Prepare a solution: using scales, measure 1 gram of sodium bicarbonate. Then, using a measuring cylinder, measure 300ml of water. Place both materials into a beaker
2. Add 1 drop of dilute liquid soap to this solution.
3. Using a hole punch, cut 10 uniform leaf discs for each trial. Be careful to not cut yourself in this process. Do not use a