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Light Dependent Reactions of Photosynthesis

Light Dependent Reactions of Photosynthesis

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Photosynthetic Pigments: Capturing the Light

This tutorial begins with the various photosynthetic pigments of the leaf. It then explores how the pigments capture photons of light energy and transfer them to the Photosytems in the thylakoid membrane.

Source: M. O'Mahony, open source figures.

Student Notes Part A

Student note template for the first part of this lesson on Photosynthetic Pigments and the capture of light.
A word document of this is saved in Ms O's notes on First Class as well.


Source: M. O'Mahony and Open Source figures

The Light Independent Reactions of Photosynthesis

This screen capture looks at the electron transport chain of the chloroplast and the role that photons of light, the two Photosystems and water play in it.
Comparison is made between the Mitochondrial ETC - which should be kept in the back of the watcher's mind during this screen capture.

Source: M. O'Mahony, Koning, Ross E. 1994. Light Reactions. Plant Physiology Information Website. (11-13-2014) (used with permission)

Student Notes Part B

This Student Notes Template is for the lesson on the Light Dependent Reactions - specifically the electron transport chain of the Chloroplast.


Source: M. O'Mahony

LabBench: Photosynthesis Experiments

Go to LabBench at The Biology Place Classic Edition

Lab 4 Plant Pigments and Photosynthesis contains 2 excellent virtual labs.

I. Chromatography separates pigments using paper chromatography.

II. Photosynthesis explores the activity of the Light Independent Reaction using DPIP.  DPIP is a chemical that               changes colour when it accepts electrons.


Source: The Biology Place, Classic Edition

BioCoach: Photosynthesis

BioCoach, another section of The Biology Place, Classic Edition from Pearson Education has an excellent interactive tutorial on photosynthesis.

It can be found at:


Source: The Biology Place, Classic Edition

Viten: Photosynthesis

This interactive tutorial is a clear, albeit simple overview of the Light Dependent Reactions of Photosynthesis and an introduction to the Light Independent Reactions (the Calvin Cycle).
The questions found in the Workbook are excellent and it is highly recommended that you work through these!

Source: Viten (Norwegian Centre for Science Education)

VCAC Animations

Photosynthesis:  The Light (Independent) Reactions

Photosystem II:


Source: National Science Foundation, US Dept of Education

Animations and Short Videos

This is a nice video from  It begins with the Properties of Light, Structure of the Chloroplast, Light Independent Reactions.  I will be reposting this in the next Tutorial (The Light Independent Reactions) for you to watch the segment on the Calvin Cycle.                                              Nice animation of non-cyclic photophosphorylation.                                                                                     A simpler animation focussing just on the Electron Transport Chain in the Chloroplast.

Source: McGraw Hill;

Photosystems I and II in the Protein Data Bank (PDB) Molecule of the Month

Photosystem II was the "Molecule of the Month" in November 2004. 

Check out their clear and well-written explanation and awesome figures at:

Photosystem I was the "Molecule of the Month" in October 2001!



Source: doi: 10.2210/rcsb_pdb/mom_2004_11 (PDF Version, ePub Version )

Cytochrome - Molecule of the Month

Cytochrom bc1 was added to the PDB in May 2011.

This protein is found in both the mitochondrial and photosynthetic electron transport chains.

Check it out at:

AND:  This article confirms that while 2 electrons move 2 protons move through proton pumps!

Source: doi: 10.2210/rcsb_pdb/mom_2011_5

Science Daily: Deep within spinach leaves, vibrations enhance efficiency of photosynthesis

Recent (July 2014) research at the University of Michigan was summarized in a Science Daily article.  The abstract reads:

""Biophysics researchers have used short pulses of light to peer into the mechanics of photosynthesis and illuminate the role that molecule vibrations play in the energy conversion process that powers life on our planet."

Check out this summary.  If you want more details you can go to the published article: 

Franklin D. Fuller, Jie Pan, Andrius Gelzinis, Vytautas Butkus, S. Seckin Senlik, et al. Vibronic coherence in                        oxygenic photosynthesis. Nature Chemistry, 13 July 2014 DOI: 10.1038/nchem.2005

Source: University of Michigan. (2014, July 13). Deep within spinach leaves, vibrations enhance efficiency of photosynthesis. ScienceDaily. Retrieved November 12, 2014 from

Science Daily: Quantum mechanics explains efficiency of photosynthesis

9 Jan 2014 from research conducted at University College, London

Light-gathering macromolecules in plant cells transfer energy by taking advantage of molecular vibrations whose physical descriptions have no equivalents in classical physics, according to the first unambiguous theoretical evidence of quantum effects in photosynthesis.

Research article can be found at:

 Edward J. O’Reilly, Alexandra Olaya-Castro. Non-classicality of the molecular vibrations assisting exciton energy                 transfer at room temperature. Nature Communications, 2014; 5 DOI: 10.1038/ncomms4012

Source: University College London. "Quantum mechanics explains efficiency of photosynthesis." ScienceDaily. ScienceDaily, 9 January 2014. .

The Light Reaction Game

A reminder that you need an account on Spongelab to access the resources. It is free to set up an account.

Search: Photosynthesis  then look under "Games and Simulations".

Source: Spongelab