Lesson 4 Laboratory: Photosynthesis
Introduction: Elodea is a species of aquatic plant often called waterweed. Like other plants, Elodea absorbs carbon dioxide and releases oxygen during photosynthesis.
In this lab, an Elodea specimen is submerged in water under a lamp with a filter that can change the color of the light. We will measure Elodea's rate of photosynthesis by measuring the amount of oxygen it produces. We will investigate the effects of light color and light intensity on Elodea's rate of oxygen production.
Baking soda (sodium bicarbonate, Na HCO3) breaks down to release CO2 when mixed with water, so adding it to the water increases the availability of CO2.By placing the Elodea plant into water containing varying levels of…show more content…
4. Based on what you already know about photosynthesis, write a testable hypothesis to explain the influence of an increase in carbon dioxide on the photosynthetic rate in tomato leaves.
An increase in carbon di oxide concentration increases the photosynthetic rate in tomato leaves.
To test the hypothesis
The plant is supplied with increasing CO2 levels and rate of photosynthesis is measured.
a. Write the generalized CHEMICAL reaction of photosynthesis.
6 CO2 + 6H2O Sunlight and chlorophyll C6H12O6 + 6O2
b. Explain how the light-dependent and light-independent reactions are interdependent.
The products of the light dependent reactions, ATP and NADPH, are used to drive the synthesis of sugars which occurs through the light independent reactions.
c. Summarize the light-dependent reactions of photosynthesis, being sure to indicate where the reactions occur and the products of the reactions.
Light-dependent reaction of photosynthesis light energy is absorbed by the pigments present in the antenna, and funnelled to special chlorophyll a molecules called reaction centre chlorophylls.
There are two photosystems, PS I and PS II. PS I has a 700 nm absorbing chlorophyll a P700 molecule at its reaction centre, while PS II has a P680 reaction centre that