10 wave lengths effect on photosythesis

Aim of what were trying to investigate

chloroplasts contain many different pigment each absorb different wave length of light. by using filters were able to block out light certain rays of light only leaves one colour this will decrease the rate of photosynthesis.

how can we measure rate

using volume of gas collected ( in this case oxygen)

method

1. place a piece of bond weed into a beaker

2. use aluminium foil to block out light and cover other sides with a filter

3. add sodium hydrogen carbonate to the water to provide CO2

4. leave for 5 mins to equilibrate

5. measure the rate of photosynthesis

6. repeat with different filters

what do we add to the water to provide carbon dioxide

sodium hydrogen carbonate

what is a photosynthometer what does it measure

A photosynthometer is an apparatus used to measure the rate of photosynthesis by measuring the oxygen produced per unit time

what would the conclusion / findings be from this study

• when you have a filter on the rate of photosynthesis decreases

• when the filter is green photosynthesis will be at its lowest as only green light passes through ( transmitted) and this is light wave length/ colour reflected by plants not absorbed

• volume of gas produced proportional to rate

hazards of this practical

variable to control

1. distance of light source

2. temp

3. CO2 conc ( so amount of sodium hydrogen carbonate )