Concept explainers
(a)
To Calculate:
The value of
Introduction:
Oxygen is produced during the photosynthesis and this oxygen evolution rate is measured. Method of calibration is used having the hydrogen peroxide and the précised reading of the oxygen concentration is ensured by using the catalyst. The oxygen that is above the air saturated level is measured.
Explanation of Solution
The light quantum energy is determined using the given formula,
Where,
H=Planck’s constant
c=light speed
N=avogardo’s number
For one mole of photon 870nm we have,
As 2 moles of quanta is considered,
The free change of energy for the reaction is calculated by determining the change of the standard potential,
Now G is calculated as,
(b)
To predict:
For the plastoquinone by 700 nm light
Introduction:
Oxygen is produced during the photosynthesis and this oxygen evolution rate is measured. Method of calibration is used having the hydrogen peroxide and the précised reading of the oxygen concentration is ensured by using the catalyst. The oxygen that is above the air saturated level is measured.
Explanation of Solution
The light quantum energy is determined using the given formula,
Where,
H=Planck’s constant
c=light speed
N=
For one mole of photon 700nm we have,
As 2 moles of quanta is considered,
The free change of energy for the reaction is calculated by determining the change of the standard potential,
Now G is calculated as,
(c)
To predict:
For the plastoquinone by 680 nm light
Introduction:
Oxygen is produced during the photosynthesis and this oxygen evolution rate is measured. Method of calibration is used having the hydrogen peroxide and the précised reading of the oxygen concentration is ensured by using the catalyst. The oxygen that is above the air saturated level is measured.
Explanation of Solution
The light quantum energy is determined using the given formula,
Where,
h=Planck’s constant
c=light speed
N=Avogadro’s number
For one mole of photon 680nm we have,
As 2 moles of quanta is considered,
The free change of energy for the reaction is calculated by determining the change of the standard potential,
Now G is calculated as,
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Chapter 21 Solutions
Biochemistry
- The Relative Efficiency of ATP Synthesis in Noncyclic versus Cyclic Photophosphorylation If noncyclic photosynthetic electron transport leads to the translocation of 7 H+/2e- and cyclic photosynthetic electron transport leads to the translocation of 2 H+/e-, what is the relative photosynthetic efficiency of ATP synthesis (expressed as the number of photons absorbed per ATP synthesized) for noncyclic versus cyclic photophosphorylation? (Assume that the CF1CF0-ATP synthase yields 3 ATP/14 H+.)arrow_forwardIn cyclic photophosphorylation, it is estimated that two electrons must be passed through the cycle to pump enough protons to gener- ate one ATP. Assuming that the AG for hydrolysis of ATP under con- ditions existing in the chloroplast is about –50 kJ/mol, what is the corresponding percent efficiency of cyclic photophosphorylation, using light of 700 nm?arrow_forwardIs it reasonable to list standard reduction potentials for the reactions of photosynthesis? Why or why not?arrow_forward
- In cyclic photophosphorylation, it is estimated that two electrons must be passed through the cycle to pump enough protons to generate one ATP. Assuming that the AG for hydrolysis of ATP under conditions existing in the chloroplast is about –50 kJ/mol, what is the corresponding percent ef- ficiency of cyclic photophosphorylation, using light of 700 nm?arrow_forwardIt is believed that the ratio of cyclic photophosphorylation to noncyclicphotophosphorylation changes in response to metabolic demands. Ineach of the following situations, would you expect the ratio to increase,decrease, or remain unchanged?(a) Chloroplasts carrying out both the Calvin cycle and the reduction ofnitrite (NO2-) to ammonia (This process does not require ATP.)(b) Chloroplasts carrying out not only the Calvin cycle but also extensiveactive transport(c) Chloroplasts using both the Calvin cycle and the C4 pathwayarrow_forwardWhat is midpoint potential of redox active centers in photosynthetic organisms? What factors affect this? Also how does charge become offset during water oxidation rxns?.arrow_forward
- a Assuming that the concentrations of ATP, ADP, and P; in chloroplasts are 3.15 mM, 1.00 mM, and 11.0 mM, respectively, what is the AG for ATP synthesis at 31.0 °C? (AGO' = 30.5 kJ/mol) AG = kJ/mol Submitarrow_forwardIn cyclic photophosphorylation in photosystem I, ATP is produced, even though water is not split. Explain how the process takes place.arrow_forwardc) . solar photons. Describe two ways through which Photosystem I and Photosystem II optimize the capture of d) good oxidant and a good reductant at the same time. With a simple frontier orbital diagram, explain why the photo-excited P680 pigment is both aarrow_forward
- Identify the chemical basis for ApH and AY across the chloroplast thylakoid membrane by dragging the descriptions to their targets. Be sure to notice that the upper arrow iindicates ApH and the lower arrow indicates ΔΨ. ATP synthase complex H+ N ADP + P₁ Light energy ATP H*N Photosystem I/II- Chloroplast N side Aus PN ApH T + Thylakoid membrane HTp H+p Lumen Stroma P side Proton circuit A B High H concentration Low positive charge High positive charge Low H+ concentration Within the image, identify the types of proton translocation by dragging each label to its target. O XH₂ 2H+ + Z 2 H* ZH₂ O XH₂ Z 2H+ ZH₂ 2H+ C A B Proton pump Redox looparrow_forwardCalculate (in kJ/mol) the energy that is required by the Rhodopseudomonas viridis photophosphorylation system to synthesize 3 ATP? (Assume that the R. viridis F1F-ATP synthase c-subunit rotor contains 12 c-subunits and that the R. viridis cytochrome b/c complex translocates 2 H/e". Also assume that the wavelength of lig! is 680 nm.) Number of photons required to synthesize 3 ATP = photons Energy = kJ/molarrow_forwardThe net equation for oxidative phosphorylation can be written as 2NADH + 2 H+ + O2 →2 H2O + 2 NAD+. Write an analogous equation for the light reactions of photosynthesis.arrow_forward
- BiochemistryBiochemistryISBN:9781305577206Author:Reginald H. Garrett, Charles M. GrishamPublisher:Cengage Learning