photosynthesis lab

photosynthesis lab - light versus dark and boiled versus...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Tinuke Omolara Due: November 7, 2006 AP Biology Lab Photosynthesis In the light reaction of photosynthesis, light energy excites electrons in plant pigments such as chlorophyll and boosts them to a higher energy level. These high-energy electrons reduce compounds (electrons acceptors) in the thylakoid membrane, and the energy is eventually captured in the chemical bonds of NADPH and ATP. To measure light transmittance in chloroplasts a colorimeter will be used. The reason behind measuring the light transmittance is to calculate the rate of photosynthesis in the chloroplasts. A solution called DPIP will be used in place of NADP to judge the absorbance of the chloroplast solutions. The colorimeter is used to measure the color change, which gives an indication of the rate of the light reactions of photosynthesis under various conditions. Our goal is to determine the rate of photosynthesis under different conditions such as
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: light versus dark and boiled versus unboiled chloroplasts. Fingerprints on either the paper or the cuvettes may have affected the experiment because the oil from your hands can get on the surfaces and affect the colorimeter reading. The foil on the dark cuvette made the surface cleaner because it was handled with the foil wrapped most of the time. The foil covering may have also beena hinderance for it may not have done its job covering the cuvette properly. After taking the foil off to take the absorbancy reading, it may have become slack. Table 1 Time (min) Absorbance unboiled Absorbance in dark Absorbance boiled .239 .311 .25 5 .073 .186 .179 10 .073 .035 .166 15 .077 .022 .157 20 .094 .032 .157 Table 2 Chloroplast Rate of Photosynthesis Unboiled .005 Dark .0144 Boiled .00416...
View Full Document

This note was uploaded on 04/18/2008 for the course CHEM 1034 taught by Professor Devicaris during the Spring '08 term at Temple.

Ask a homework question - tutors are online