• my on-line schedule   (I try to keep this updated.)
• Here's a link to something that both courses (Biol 1000 and Biol 1001) might find useful:
  • Photosynthesis (light reactions)

[Warning:  not all links are active yet!]

• my Biol 1000 page   Last updated March 15, 2004
• Lab Section 92 (MW 7:30-9:00pm, SC 105):
• Lab Exam 1, Lab Quiz 1, & Lab Chapters 1 & 2 scores are now available on-line.  (out of 52 pts possible)
• Check your code words for Lab Section 92

• my Biol 1001 page   Last updated March 20, 2004
• Lab Section 72 (Sat. 11:45am-2:30pm, SC 111):
  Last updated March 20, 2004
• Lab Quiz 1, Homework 1, Homework 2 (D/O graph), and Lab Exam 1 scores and statistics are now available on-line.  (out of 60 pts possible)

LAB PURPOSE

This laboratory constitutes an introduction to photosynthesis.   More specifically, we will concentrate on the concepts of reflection, absorption and transmittance of visible light.  The focus of the lab itself is on extracts of plant pigments, and the paper chromatographic analysis of the pigment extracts.  That is, we will work with paper chromatography, which is a way in which different pigments will separate from a solution at different rates, depending on their solubility in the development solution (and water).

QUESTIONS AND KEY CONCEPTS

1.   Why is the thylakoid membrane itself so important?
2.   Why do plants appear green?
3.   What is the overall purpose of the photosynthetic pathway?
4.   What is the function of a photosystem?
5.   Compare & contrast photosynthesis with respiration
      (in general terms, such as overall products & reactants).
6.   Explain how we separated and identified various pigments that make up the
      photosystems.
7.   Understand the idea of hydrophobic vs. hydrophilic substances, and how paper
      chromatography can work to separate compounds based on their attraction to
      water molecules.
8. Know that the amount of light absorbed by the extract is the sum of the light
      absorbed by the individual pigments in the extract sample.

9. What do plants get from sunlight that they don’t get from green light?

• “Substances that absorb visible light are called pigments.  Different pigments absorb light of different wavelengths, and the wavelengths that are absorbed disappear.” (page 188, Campbell)
• Reflected and transmitted wavelengths have the same wavelength “going in as coming out”.
• Fluorescence is when one wavelength of light “goes in” (is absorbed), but a different wavelength “comes out” (is emitted).

ANSWERS to QUESTIONS AND KEY CONCEPTS

9. Plants do not get the energy they need to run photosynthesis from green light.

BiologyByTheresa.com

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