Question

Emerson’s enhancement effect and Red drop have been instrumental in the discovery of
a. Photophosphorylation and non-cyclic electron transport
b. Two photosystems operating simultaneously
c. Photophosphorylation and cyclic electron transport
d. Oxidative Photophosphorylation

Answer 1

Robert Emerson was the name of the scientist who discovered the Emerson enhancement effect. In this effect, the rate of photosynthesis increases. The drop off in the photochemical efficiency with wavelength more than 680 nm is called Red drop effect. In the quantum field, it decreases the sharp.

Complete answer:
The rate of photosynthesis increases after the chloroplasts are exposed to light wavelength 670 nm (red light) and 700 nm (far-red light) and this process is known as the Emerson enhancement effect. The rate of photosynthesis will be higher than the sum of red and far-red light when they both are simultaneously exposed to the light of both wavelengths in the photosynthesis rate. The efficiency of 700 nm is shown which is a huge drop and the overall phenomenon is known as the Red drop effect.

When the wavelengths are greater than 680 nm then a sharp decrease in quantum yield is noticed and this will present in the red part of the spectrum. Thus, the quantum yield of photosynthesis says that the number of oxygen molecules released per quanta of light. This whole process was first detected by Robert Emerson and after that, it named the Emerson Enhancement effect.
Therefore, in both the above processes two photosystems are included in the light reaction of photosynthesis.

- The process of conversion of ADP to ATP by using sunlight energy through photosystem II (PS II) activation.
- Non-cyclic electron transport is the process of electron transfer from water to ferredoxin through two light reactions and in between carriers.
- In cyclic electron transport, only photosystem (I) is involved. The process of photolysis of water does not take place in this.
- The cycle which is made from the two connected components which are named as electron transport chains and chemiosmosis is called Oxidative Phosphorylation.

Hence, the correct answer is option (B).

Note: Both the effects are introduced and consist of two photosystems PSI and PSII. The photosynthetic experiment of the Emerson effect takes place on Chlorella. The red drop effect observes on monochromatic light. The Emerson Enhancement effect observes on synchronized light of 680 nm and 700 nm. Both processes take place in the photosynthesis of plants.