What is Photosynthesis?

Although seemingly simple in concept, the photosynthesis process is very complicated. Follow these links to articles that discuss photosynthesis at varying degrees of complexity.

• Introduction to Photosynthesis and Its Applications -- A basic introduction to photosynthesis which explains many areas studied by photosynthesis researchers and highlights much of the work we do at the Photosynthesis Center. Written by Prof. Wim Vermaas from our own Photosynthesis Center. [level: middle school and above]

• Photosynthesis and the World Wide Web -- An article presented at the XI^th International Photosynthesis Congress (Aug. 1998), that discusses how to find photosynthesis-related information on the web.

• Why Do Leaves Turn Color in Fall?--Reproduced by permission from Science Made Simple, an excellent source of science information for elementary through middle school children (and their parents!). Includes some easy experiments/demonstrations. [level: elementary through middle school]

• Once you know why leaves turn color, Fall Foliage on the Web is a great place to look if you want to know when and where the leaves are changing.[level: all ages]

• Photosynthesis: Don't "Leaf" Out Fall's Most Valuable Lesson! from Education World also discusses photosynthesis and fall leaves. [level: elementary through middle school]

• Newton's Apple TV program on Photosynthesis--some very basic definitions and projects [level: elementary through middle school]

• Photosynthetic Pigments--why plants are green and other colors, from the University of California Museum of Paleontology [level: elementary through college]

• Using photosynthesis in a high school biology class--a section of the National Science Education Standards from the National Academy of Sciences showing how photosynthesis can be used to teach the scientific method and show the development of scientific knowledge. [level: high school]

• Photosynthetic Pictures--Are Worth More Than a Thousand Words--a good classroom guide to preparing starch photos. [level: high school]

• Photosynthesis--by M. J. Farabee. An excellent introduction to the entire photosynthetic process. [level: high school to undergraduate]

• Photosynthesis--a very good hypertext book from the Massachusetts Institute of Technology. [level: high school to undergraduate]

• ASU Research: The Power of Green--a cover story and related articles about what we do at the ASU Photosynthesis Center. [level: high school to undergraduate]

• Lecture 7 on Photosynthesis from the University of Illinois--a very good graphic introduction to plant and leaf photosynthesis. The section on the Virtual Chloroplast is great! [level: high school to undergraduate] [Link has died, searching for new one]

• How Plants Cope with Desert Climate from the Arizona-Sonora Desert Museum--explains how plants in desert areas use a special photosynthetic adaptation called CAM. [level: all ages]

• Form and Photosynthesis in Vascular Plants--from Prof. Thomas J. Herbert, University of Miami: explains why plants have leaves and why some move around. A simple model of canopy photosynthesis rates is also presented. [level: high school to undergraduate]

• Modelling of Canopy Photosynthesis--looks at photosynthesis rates of groups of plants in their environment. [level: undergraduate college] [Link has died, searching for new one]

• Photosynthetic Antennas and Reaction Centers--a good introduction to some of the technical aspects of photosynthesis by Robert E. Blankenship from our own ASU Photosynthesis Center [level: undergraduate college]

• The Photosynthetic Process--a good review of photosynthesis by John Whitmarsh and Govindjee from the University of Illinois [level: high school to undergraduate]

• Bacterial Photosynthesis--a good site from the University of Illinois, Dept. of Microbiology, many nice figures [level: high school to undergraduate]

• Light Harvesting in Bacterial Photosynthesis--from the Theoretical Biophysics Group at the University of Illinois, Urbana: very good up-to-date coverage of the topic and many excellent figures. [level: undergraduate college]

• Introduction to Cyanobacteria--from UC Berkeley: an introduction to some very important bacteria and includes information about cyanobacterial fossils. [level: high school to undergraduate]

• Everyday Photosynthesis--from Kapi'olani Community College/University of Hawaii: photosynthetic redox equations. [level: high school to undergraduate college]

• The First 100 Picoseconds of Photosynthesis--from Cornell: information about antenna systems; includes MPEG movie. [level: undergraduate college]

• The bc₁ Complex Home Page--from Tony Crofts' lab at the University of Illinois. Contains numerous links to illustrations and other labs studying the bc₁ complex. [level: high school to undergraduate college]

• Structure and Function of Photosystem II--from Tony Crofts' lab at the University of Illinois. [level: undergraduate to graduate college]

• The Photosynthetic Reaction Center from the Purple Bacterium Rhodoseudomonas viridis --by Peter Nixon from the Dept. of Chemistry, Imperial College, London. Note: this site requires Chime^TM, a Netscape plug-in which is available here. [level: undergraduate college]

• Field Photosynthesis Measurement Systems --a group from New Mexico State University shows how instruments are used to measure photosynthesis rates outdoors in nature. [level: high school to undergraduate college]

• Chlorophyll Fluorescence--from Opti-Sciences, a manufacturer of fluorometers. [level: undergraduate college]

I Didn't Know That!

• Faux photosynthesis
  "Greg Van Patten may be the only materials scientist who claims chlorophyll as his muse. A bioscience researcher at Los Alamos National Laboratory, Van Patten is developing films that could be used to coat roofing tiles.Dyes in the film would imitate photosynthesis, collecting energy from the sun and converting it to electricity. On a clear day, the sun transmits about a kilowatt of power per square meter. While plants use that energy to convert water and CO2 into food, Van Patten's tiles can use the energy to power your VCR or Mr. Coffee - and we're talking about hours of video and many pots of coffee. Traditional semiconductor solar cells collect only a limited portion of the light spectrum, but the Los Alamos tiles are treated with layers of films, each tinted with a dye designed to absorb a particular wavelength of light. A stack of different-colored layers can soak up many wavelengths of light." From a Wired article Small Parts: A users' guide to out-of-the-box living.

• "The oceans cover over 70% of the Earth's surface. Just from the sheer coverage and volume, the phytoplankton environment can be thought of as the world's most expansive jungle. Its affect on the Earth's life, climate, and geology is significant. Being at the bottom of the pelagic food-chain, it is literally the source of most oceanic life. Through photosynthesis, it may affect the Earth's climate by absorbing a significant portion of the world's carbon dioxide. When phytoplankton die, if their carbon is not consumed by other living creatures first, it settles on the ocean bottom and eventually is locked-up in sedimentary rock. This rock can reenter the Earth's crust from which it may be eventually emitted back into the atmosphere again through volcanism; part of the process known as the carbon cycle, which affects long-term global change. " From: MODIS OPP/SCF: Overview, NASA scientists that are studying phytoplankton.

• "An average hectare of corn produces enough oxygen per hectare per day in mid summer to meet the respiratory needs of about 325 people. This means that the one million or so hectares of corn grown in Ontario produce enough oxygen for the annual respiratory needs of Ontario's 10 million residents in about 11 summer days!" From: Corn and Photosynthesis

• "It is hard to see under the sea-particularly if you are 120 meters down, lying beneath a thick covering of ice during the endless nights of the Antarctic winter. Yet even in this deep night, hoards of tiny algae live inside sponges, soaking up carbon dioxide and, in turn, producing nutrients for their hosts. The mystery has been where these minute green plants get the light they need to drive photosynthesis." From: Scientific American: Science and the Citizen (February, 1997)

• "The Aztecs settled near the marshy shores of Lake Tenochtitlan. Since this fresh water lake was surrounded by marshes and rising hills, the Aztecs were faced with the problem of trying to find a place to grow food. They solved this problem with the incredible ingenuity which led them to become a great civilization." From: The Hydroponic Instructional Package from Cornell University. A good introduction to growing plants without soil. But you'll still need the sun, water, and carbon dioxide for photosynthesis!

• "Besides its role in catalyzing plant growth, Rubisco has two traits that invite--and defy--analysis. While most enzymes catalyze only one reaction, Rubisco triggers two. One is carbon fixation, the basis of photosynthesis, which enables plants to make food. The other--and here's the rub--is a competing, oxygen-fixation reaction that actually undoes photosynthesis. Picture a nozzle pumping gasoline into your car, and inside, a smaller siphon removing gas at the same time." From: Life Sciences - Staff of Life

• "The iron hypothesis, developed by the late John Martin of Moss Landing Marine Laboratories, has received international notice over the past few years. This idea was linked to global climate by Martin, who realized that the atmospheric transport of large amounts of dust to the ocean could stimulate photosynthesis by microscopic marine plants, called phytoplankton. Increased plant production in the ocean would then draw down atmospheric carbon dioxide, a "greenhouse" gas, thus cooling the earth, Martin believed. Records of ancient atmospheric conditions preserved in ice cores on the Antarctic continent suggest that this process has, in fact, occurred in the past." From: NSF And ONR-Supported Oceanographers Report Results of "Iron Experiment": Findings Shed Light on Ocean/Atmosphere Climate Link

• "Scientists have recently discovered microorganisms living within igneous formations -- extremely hard rock lacking organic nutrients. The industrious residents of these rocks fashion their own organic molecules out of the barest of inorganic materials.
  Relying only on hydrogen, water, and carbon dioxide -- all of which are products of Earth's interior --these microbes are unique among the vast array of living species. All other organisms depend to some extent on the sun's energy, which is harnessed through photosynthesis and creates food for surface life. Even organisms living near seafloor vents rely indirectly on the oxygen supplied by photosynthesis, says Todd O. Stevens of Battelle." From: Deep Dwellers: Microbes Thrive Far Below Ground (Science News, 151: 192-193--not all life needs photosynthesis, but the exceptions are pretty amazing!

Student Pages

High School Level:

• Photosynthesis is Fun!--created by students at Community High in Ann Arbor, MI

College Level:

• Photosynthesis in the Ocean--Included in "Biological Productivity in the Oceans" by Paul Hopkinson at UC Santa Barbara

• Non-Destructive Coral Health Monitoring--an interesting Senior Thesis project by Chris Mattia of St. Mary's College of Maryland using photosynthesis techniques to monitor the health of coral reefs.

Other

Revised Thursday, March 30, 2000

Visit the Photosynthesis Center home page