The Wavelemgth of Light and Its Energy

The Wavelemgth of Light and Its Energy

  • Submitted By: cdk058
  • Date Submitted: 02/24/2009 11:17 AM
  • Category: Science
  • Words: 865
  • Page: 4
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1) Describe the physical properties of light and explain the relationship between a wavelength of light and its energy.

□ Light consists of particles called photons that move as waves. Photons with shorter wavelengths have more energy than those with longer wavelengths.

2) Diagram the internal structure of a chloroplast, and explain how its components interact and facilitate the process of photosynthesis.

□ In plants, photosynthesis occurs in chloroplasts, which are located mainly within mesophyll cells inside the leaf.
□ Chloroplasts are organelles enclosed by a double membrane; the inner membrane encloses the stroma in which membranous, saclike thylakoids are suspended. Each thylakoid encloses a thylakoid lumen. Thylakoids arranged in stacks are called grana.
□ Chlorophyll a, chlorophyll b, carotenoids, and other photosynthetic pigments are components of the thylakoid membranes of chloroplasts.

3) Describe what happens to an electron in a biological molecule such as chlorophyll when a photon of light energy is absorbed.

□ Photons excite biological molecules such as chlorophyll and other photosynthetic pigments, causing one or more electrons to become energized. These energized electrons may be accepted by electron acceptor compounds.
□ The combined absorption spectra of chlorophylls a and b are similar to the action spectrum for photosynthesis.

4) Describe photosynthesis as a redox process.

□ During photosynthesis, light energy is captured and converted to the chemical energy of carbohydrates; hydrogens from water are used to reduce carbon, and oxygen derived from water becomes oxidized, forming molecular oxygen.

5) Distinguish between the light-dependent reactions and carbon fixation reactions of photosynthesis

□ In the light-dependent reactions, electrons energized by light are used to generate ATP and NADPH; these compounds provide energy for the formation of carbohydrate...

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