In the Light Reaction of Photosynthesis, the sun excites electrons in pigment molecules in the photosystems. These excited electrons and (H+ ions) go through electron transport systems. Keep in mind that if this process continued as stated, the pigment molecules would run out of electrons, but fortunately there is a way in which the excited electrons are replaced. Explain how the electrons are ultimately replaced and what the important byproduct is.

In the Light Reaction of Photosynthesis, the sun excites electrons in pigment molecules in the photosystems. These excited electrons and (H+ ions) go through electron transport systems. Keep in mind that if this process continued as stated, the pigment molecules would run out of electrons, but fortunately there is a way in which the excited electrons are replaced. Explain how the electrons are ultimately replaced and what the important byproduct is.

BIOLOGY:CONCEPTS+APPL.(LOOSELEAF)

10th Edition

ISBN:9781305967359

Author:STARR

Publisher:STARR

Chapter20: The Protists

Section: Chapter Questions

Problem 4CT: Melvin Calvin and Andrew Benson determined the steps in the light-independent reactions of...

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Melvin Calvin and Andrew Benson determined the steps in the light-independent reactions of photosynthesis by exposing the green alga Chlorella to CO2 labeled with the radioisotope carbon 14. By looking at which compounds the C14 ended up in, they were able to identify all intermediates in this cyclic pathway. Why did they predict correctly that the same set of intermediates would be formed in the light reaction in land plants?
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Assume a thylakoid is somehow punctured so that the interior of the thylakoid is no longer separated from the stroma but the photosystems and membrane proteins of the electron transport chain are unharmed. This damage will have the most direct effect on which of the following processes?
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Bacterium Y is photosynthetic. You want to decrease the ability of Bacterium Y to produce glucose through photosynthesis. Explain how you could manipulate the light reactions of photosynthesis to decrease glucose production during the dark reactions in Bacterium Y. Include the name of the pathway that makes glucose during the dark reactions, which/how molecules from the light reactions are used in this pathway, and what specific steps of this pathway would be affected by your manipulations.
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After electrons are raised to high energy levels in photosystem II, they travel down an electron transport chain. As they are stepped down in energy, the lost energy is used to power which process. The pumping of high energy electrons into the intermembrane space. This creates a large difference in concentration and in electric charge between the intermembrane space and the lumen of the thylakoid. When these high energy electrons rush back into the thylakoid lumen, they are forced to travel through one of the ATP synthase molecules that sits embedded in the thylakoid membrane. ATP synthase uses the flow of hydrogen ions to phosphorylate ADP, converting it to ATP. The pumping of hydrogen ions into the stroma. This creates a large difference in concentration and in electric charge between the stroma and the lumen (watery interior) of the thylakoid. When When the hydrogen ions in the stroma rush back into the thylakoid lumen, they are forced to…
In biochemistry, the exergonic process ofconverting glucose and oxygen to carbon dioxide and water in aerobic metabolism can be considered the reverse of photosynthesis,in which carbon dioxide and water are converted to glucose andoxygen. Do you expect both processes to be exergonic, both endergonic, or one exergonic and one endergonic? Why? Would youexpect both processes to take place in the same way? Why?
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