#Question id: 9587
#Unit 6. System Physiology – Plant
The structure of the four major protein complexes in the thylakoid membrane are organised form such as ;
a.) PSII is located predominantly in the stacked regions of the thylakoid membrane and Cytochrome b6f complexes are evenly distributed
b.) PSI and ATP synthase are found in the unstacked regions protruding into the stroma
c.) Lateral separation of the two photosystems requires that electrons and protons produced by PSII be transported directly to PSI and the ATP coupling enzyme
d.) Four main protein complexes of the thylakoid membrane, shown also are the two diffusible electron carriers—plastocyanin, which is located in the thylakoid lumen, and plastohydroquinone (PQH2) in the membrane, The lumen has a positive electrical charge with respect to the stroma
Which of the following statements correct?
#Question id: 9588
#Unit 6. System Physiology – Plant
The light-absorbing antenna systems are organised in different manner, which of the following statements about antenna would be Incorrect?
#Question id: 9589
#Unit 6. System Physiology – Plant
The physical mechanism by which excitation energy is conveyed from the chlorophyll that absorbs the light to the reaction centre, By this mechanism the excitation energy is transferred from one molecule to another by a nonradioactive process, this mechanism is known as
#Question id: 9590
#Unit 6. System Physiology – Plant
The efficiency of energy transfer between the two tuning forks depends on their distance from each other and their relative orientation, as well as on their vibrational frequencies, or pitches, Energy transfer in antenna complexes is usually very efficient;
#Question id: 9591
#Unit 6. System Physiology – Plant
In light reaction, the funneling of excitation from the antenna system toward the reaction centre has been shown,
a.) The excited-state energy of pigments increases with distance from the reaction centre; that is, pigments closer to the reaction centre are lower in energy than those farther from the reaction centre
b.) The energy gradient ensures that excitation transfer toward the reaction centre is energetically favorable and that excitation transfer back out to the peripheral portions of the antenna is energetically unfavourable
c.) Some energy is lost as heat to the environment by this process, but under optimal conditions almost all the excitation energy absorbed in the antenna complexes can be delivered to the reaction centre
d.) The excited-state energy of pigments decreases with distance from the reaction centre
Which of the following above combination is true?
#Question id: 9592
#Unit 6. System Physiology – Plant
The function of light is to excite a specialized chlorophyll in the reaction centre either by Direct absorption or more frequently, via energy transfer from an antenna pigment, This excitation process can be envisioned as
a.) An electron from the lowest-energy filled orbital of the chlorophyll to the highest-energy unfilled orbital
b.) An electron in the upper orbital is only tightly bound to the chlorophyll and is difficult to fetch the electron nearby molecules
c.) The electron in the upper orbital is only loosely bound to the chlorophyll and is easily lost if a molecule that can accept the electron is nearby
d.) The promotion of an electron from the highest-energy filled orbital of the chlorophyll to the lowest-energy unfilled orbital
Which combination is CORRECT?