BIOENERGETICS
PHOTOSYNTHESIS
Endothermic reaction
CARBON DIOXIDE + WATER > GLUCOSE + OXYGEN
RATE OF PHOTOSYNTHESIS
o Temperature: the rate of photosynthesis increases with an increase in temperature
o Light intensity: the higher the light intensity the faster the rate of reaction
o Carbon dioxide concentration: as the concentration increases so does the rate of
reaction
o Amount of chlorophyll: if there is less chlorophyll the rate of photosynthesis
decreases
RATE OF PHOTOSYNTHESIS EXPERIMENT
o Put a 10cm piece of pondweed into a beaker of water
o Cover the pondweed with an inverted filter funnel
o Fill the measuring cylinder with water
o Use the ruler to position the beaker of pondweed 1m away from the light source
o Start the stop watch and:
Count and record the number of bubbles released in three minutes
Record the volume of gas produced and collected in the measuring cylinder
in the same time
o Repeat the experiment, moving the light source 20cm closer each time
LIMITING FACTORS
o A limiting factor is something that can affect the rate of a chemical reaction
o LIGHT INTENSITY
As the light intensity increases, so does the rate of photosynthesis
The rate of reaction begins to level off as there is another limiting factor
Further increases in light have no effect because the other factor is limiting
the rate of reaction
o CARBON DIOXIDE CONCENTRATION
As the carbon dioxide concentration increases, so does the rate of
photosynthesis
The rate of reaction begins to level off as there is another limiting factor
Further increases have no effect because the other factor is limiting the rate
of reaction
o TEMPERATURE
As the temperature increases so does the rate of reaction - the particles
have greater energy so there are more successful collisions
At the optimum temperature photosynthesis occurs at its fastest rate
Any further increases in temperature cases the enzymes to denature and
the rate of photosynthesis falls quickly
PHOTOSYNTHESIS
Endothermic reaction
CARBON DIOXIDE + WATER > GLUCOSE + OXYGEN
RATE OF PHOTOSYNTHESIS
o Temperature: the rate of photosynthesis increases with an increase in temperature
o Light intensity: the higher the light intensity the faster the rate of reaction
o Carbon dioxide concentration: as the concentration increases so does the rate of
reaction
o Amount of chlorophyll: if there is less chlorophyll the rate of photosynthesis
decreases
RATE OF PHOTOSYNTHESIS EXPERIMENT
o Put a 10cm piece of pondweed into a beaker of water
o Cover the pondweed with an inverted filter funnel
o Fill the measuring cylinder with water
o Use the ruler to position the beaker of pondweed 1m away from the light source
o Start the stop watch and:
Count and record the number of bubbles released in three minutes
Record the volume of gas produced and collected in the measuring cylinder
in the same time
o Repeat the experiment, moving the light source 20cm closer each time
LIMITING FACTORS
o A limiting factor is something that can affect the rate of a chemical reaction
o LIGHT INTENSITY
As the light intensity increases, so does the rate of photosynthesis
The rate of reaction begins to level off as there is another limiting factor
Further increases in light have no effect because the other factor is limiting
the rate of reaction
o CARBON DIOXIDE CONCENTRATION
As the carbon dioxide concentration increases, so does the rate of
photosynthesis
The rate of reaction begins to level off as there is another limiting factor
Further increases have no effect because the other factor is limiting the rate
of reaction
o TEMPERATURE
As the temperature increases so does the rate of reaction - the particles
have greater energy so there are more successful collisions
At the optimum temperature photosynthesis occurs at its fastest rate
Any further increases in temperature cases the enzymes to denature and
the rate of photosynthesis falls quickly
