General Knowledge - Biology - Discussion

Why no photosynthesis takes place in blue color light, and why minimum photosynthesis takes place in green color light, and Why the rate of photosynthesis is maximum in red color light?

Answer 1:

That is a great question, light is a very tricky thing as it comes in various forms of energy levels. UV light (close to purple and blue) is very high energy and that's why we get sunburned. On the other side of the spectrum is Infrared (close to red) which is seen in night vision goggles and can be seen from heat emitting from our bodies, a relatively low energy light. Plants, just like us can only tolerate certain wavelengths of light, especially for the chemical reactions of photosynthesis. Photosynthesis occurs when pigments, molecules in the plant cell, absorb light photons and transfer them around to create chemical energy. These pigments are picky in terms of which light they can use. There are two types of Chlorophyll pigments, A and B. Chlorophyll A absorbs a lot of red and some blue while Chlorophyll B absorbs a lot of blue and some red. Neither absorb green much which is why plants appear green.

Answer 2:

Chlorophyll absorbs red light. No light gets absorbed by chlorophyll means the plant can't do photosynthesis.

Answer 3:

Trees and plants are green because of a green pigment called chlorophyll. This pigment absorbs red light the best, and converts the light into energy that it uses for metabolism. As you likely know, this pigment allows plants to use light as a form of energy, as a part of a process called photosynthesis. Instead of eating food to build molecules, plants can take light from the sun and use the energy to convert carbon dioxide from the air into useful molecules! However, the pigment doesn't strongly absorb blue or green light, so plants can't use this energy for photosynthesis. Interestingly, we know this even from the color of plants! White light contains all the colors, and plants appear green because they absorb the red light, leaving what appears to us as green light, to be seen by our eyes! If the light isn't being absorbed by the plant, it can't be used for photosynthesis!

My dear first we know about colour & it's Temperature.

Temperature Colour
30,000-60,000K blue
10,000-30,000k blue-white
7,500-10,000k white
6,000-7,500k yellow-white
5,000-6,000k yellow
3,500-5,000k orange
3,500-3,500k red

Temperature of Sun's photosphere is average about 5'773.15 - 6,273.15k is very low from blue and higher then red. photosynthesis is a process to get maximum energy by solar light. It is also dependent on producing by solar, so it is higher in white.We can show green leaf always green colour in white light. In red blue and yellow we show it dark colour.

Emerson's Enhanced Effect tells us that in polychromatic light (provided in a discontinuous manner), the rate of photosynthesis increases as both PS 1 and PS 2 will be excited and hence both cyclic and non-cyclic photophosphorylation will take place. White light i.e. sunlight is a polychromatic light.

According to Emerson's Red Drop Effect if only red light i.e. Monochromatic light is provided to plants, photosynthetic yield will decrease as only PS 1 will be excited resulting in only cyclic photophosphorylation as red light has a wavelength of 700 nm at which only PS 1 is excited because PS 2 requires light of wavelength 680 nm for photoexcitation.

If someone has the knowledge of enhancement effect then he will come to know that although rate of photosynthesis is higher maximum in red light then followed by blue and then other colors but when they are given together the rate increases.

Interesting point is that suppose we have rate unit as simple number e.g, for red 2 and for blue 3 and when they are given together it should be 2+3=5 but interestingly it will greater than 5.
i.e, 6 or something else greater than 5 this is called enhancement effect.

Hopefully, I could explain the fact behind the answer white light is the correct answer and one-word explanation is enhancement effect.

My dear, yeah I agree with you white is not included in VIBGYOR. But it outgrowth of all the 7 colors. Red and blue color are needed in green plants.

So instead of individually getting red or blue color, white color suits the best as it produces both red and blue color whichever color (that is red and blue color) chlorophyll may need to absorb, its present in white color.

Hence, increasing the rate of photosynthesis.

I think red is the answer. Since photosynthesis takes place in red and blue light. But I partially agree that it is white because when white light is present it not only has the red region but also has the blue.

Therefore PS rate increases when supplied with white light. So, maybe white light is the correct answer after all.

Not all wavelengths of light can support photosynthesis. The photosynthetic action spectrum depends on the type of accessory pigments present. In green plants generally red n blue light needed, in red algae red, green n blue light is needed n white light is mixture of all colour so the answer should be white.

As far as the rate of photosynthesis is concerned, it is fastest in white light making the rate of photosynthesis maximum.

After White, We Have Violet Light Where Photosynthesis Occur To A Higher Extent as It Has The Shortest Wavelength Hence Has The Max Energy.

In red light only ps 1 will be excited, so only cyclic pathway will be operated but in white or mixed light both ps 1 and ps 2 will be excited. So, photosynthetic yield will increase.

This is Emerson's red drop effect and enhancement effect.

My dear friends red and blue light is the answer.

Whatever a plant getting that is white light only in that white light contains the 7 colors those are VIBGYOR. In this situation chlorophyll will absorb the red and blue light maximum.