The substance dichlorophenyldimethylurea (DCMU) is an herbicide that in-hibits photosynthesis by blocking electron transfer between plastoquinonesin photosystem II.(a) Would you expect DCMU to interfere with cyclic photophosphorylation?(b) Normally, DCMU blocks Oz evolution, but addition of ferricyanide tochloroplasts allows O, evolution in the presence of DCMU. Explain.

DCMU is a selective inhibitor of photosynthesis. It inhibits the photosystem 2. Cyclic…

Answered: The substance…

Biochemistry

9th Edition

ISBN:9781319114671

Author:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Publisher:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Chapter1: Biochemistry: An Evolving Science

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

What would be the effect on production of NADPH from photosynthesis, assuming no effect on enzyme/protein stability, if the pH of the chloroplast stroma were lowered? Why?
Which of the following sequences correctly represents the flow of electrons during photosynthesis? A) NADPH →→02→CO₂ B) H₂O NADPH → Calvin cycle C) NADPH →chlorophyll → Calvin cycle D) H₂O → photosystem I → photosystem II E) NADPH electron transport chain → 02 Place these events in the correct order: absorption of electromagnetic radiation by chlorophyll, synthesis of sugars, utilization of carbon dioxide by Calvin cycle enzymes, synthesis of NADPH, synthesis of ATP, conversion of water into molecular oxygen. Is NADP+ oxidized or reduced during the light reactions? How do you know this? What would you expect to happen if you inactivated the NADP+ reductase?
In cyclic photophosphorylation, it is estimated that two electrons must bepassed through the cycle to pump enough protons to generate one ATP.Assuming that the ∆G for hydrolysis of ATP under conditions existing inthe chloroplast is about -50 kJ/mol, what is the corresponding percent efficiency of cyclic photophosphorylation, using light of 700 nm?
Which of the following correctly sequences the steps of non-cyclic electron transport? a) Chlorophyll molecules absorb UV radiation exciting electrons which flow through photosystem I, returning to the chlorophyll molecules b) Electrons donated from water molecules pass through photosystem I then photosystem II before returning to the chlorophyll molecules, generating ATP in the process c) Water is oxidized by the capture of light energy; these excited electrons are passed through the dark reactions, returning to chlorophyll during the final light reactions d) The ATP and NADPH generated by the reactions of photosystem II and photosystem I are utilized by the Calvin Cycle to build high energy glucose molecules
Which of the following approaches would be the best way to detect the lack of photosystem II in some photosynthetic organisms? Determine whether they have thylakoid membranes. Determine whether they consume CO2 in the dark. Determine whether they produce O2 in the light. Determine the action spectrum for photosynthesis in these organisms.
Oxygenic photosynthesis in eukaryotes (in the chloroplasts of green algae and green plants) consumeswhich of the following substrate molecules (to generate glucose, water, and oxygen product molecules)?A. C12H22O11 + H2OB. C6H12O6 + 6O2 + 6H2OC. 6CO2 + 12H2OD. C6H12O6 + C6H12O6E. 6CO2 + 12H2S
Photosynthesis can be measured by measuring the rate of oxygen production. When plants are exposed to light of wavelength 680 nm, more oxygen is evolved than if the plants are exposed to light of 700 nm. Explain.
in 2005, a new species of green sulfur bacteria wasdiscovered near a geothermal vent at the bottom of the ocean. An exceptionally efficient light-harvesting mechanism allows these bacteria to carry out photosynthesis where the only illumination is a dim volcanic glow emanating from the vent. Cell membranes are required for electron transfer chains in the light-dependent reactions, but these bacteria have no internal membranes. How do you think they carry out the light-dependent reactions?
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.
Put the events in correct order: + A photon of light excites a pigment molecule in photosystem I + Excitation is transferred to the photosystem Il reaction center chlorophyll * The photosystem Il electron is replaced by splitting of water + Excitation is transferred to the photosystem I reaction center chlorophyll + An electron is donated to NADP+ + A photon of light excites a pigment molecule in photosystem II + The photosystem II reaction center chlorophyll donates an electron to photosystem I via an electron transport chain
When running cycle photophosphorylation and passaging electrons from PSI to two fully reduced PQH2s, how many photons would be necessary for the electrons to complete one cycle?
Describe how the structure of the mitochondria OR the chloroplast aids in function. 12. Why do the chlorophyll a molecules in photosystem II have an optimal absorbance of light at 680 nm, while the chlorophyll a molecules in photosystem I have an optimal absorbance of light at 700 nm? What does this tell you about the transfer of energy between these two photosystems during the light reactions?

SEE MORE QUESTIONS

Recommended textbooks for you

Biochemistry

ISBN:

9781319114671

Author:

Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Publisher:

W. H. Freeman

Lehninger Principles of Biochemistry

Biochemistry

ISBN:

9781464126116

Author:

David L. Nelson, Michael M. Cox

Publisher:

W. H. Freeman

Fundamentals of Biochemistry: Life at the Molecul…

Biochemistry

ISBN:

9781118918401

Author:

Donald Voet, Judith G. Voet, Charlotte W. Pratt

Publisher:

WILEY

Biochemistry

ISBN:

9781319114671

Author:

Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Publisher:

W. H. Freeman

Lehninger Principles of Biochemistry

Biochemistry

ISBN:

9781464126116

Author:

David L. Nelson, Michael M. Cox

Publisher:

W. H. Freeman

Fundamentals of Biochemistry: Life at the Molecul…

Biochemistry

ISBN:

9781118918401

Author:

Donald Voet, Judith G. Voet, Charlotte W. Pratt

Publisher:

WILEY

Biochemistry

ISBN:

9781305961135

Author:

Mary K. Campbell, Shawn O. Farrell, Owen M. McDougal

Publisher:

Cengage Learning

Biochemistry

ISBN:

9781305577206

Author:

Reginald H. Garrett, Charles M. Grisham

Publisher:

Cengage Learning

Fundamentals of General, Organic, and Biological …

Biochemistry

ISBN:

9780134015187

Author:

John E. McMurry, David S. Ballantine, Carl A. Hoeger, Virginia E. Peterson

Publisher:

PEARSON

SEE MORE TEXTBOOKS