Difference Between Chlorophyll a and Chlorophyll b

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Arpita Srivastava

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Chlorophyll is a crucial pigment found inside the tissues of plant cells. It assists plants in absorbing energy from the sun and converting them into food.

  • We have conducted various research studies that have shown the presence of chlorophyll in the human body.
  • According to various studies, it helps in the prevention of cancer. 
  • They also have many antioxidant properties that elevate the nutrients in the bloodstream, keeping our bodies healthy. 
  • Green plants and algae use chlorophyll to produce energy from sunlight, water, and carbon dioxide through photosynthesis.
  • During photosynthesis, water and carbon dioxide are converted into glucose, releasing oxygen into the environment.
  • When you examine the process of photosynthesis, you will see that the pigment that facilitates the process is chlorophyll. 
  • With this article, you will get answers to questions such as what chlorophyll is, why we need it, its types, and differences. 

Key Terms: Difference Between Chlorophyll a and Chlorophyll b, Chlorophyll a, Chlorophyll b, Chlorophyll, Photosynthesis, Pigments, Plants, Carbon Dioxide, Glucose


Difference between Chlorophyll A and Chlorophyll B 

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Given below are the main points of difference between Chlorophyll a and Chlorophyll b which are as follows:

Chlorophyll A Chlorophyll B
Chlorophyll a is the most important pigment found in photosynthesis. It is associated with capturing and storing sunlight. Chlorophyll b is an additional pigment used in the process of photosynthesis. Its sole function is to capture sunlight and pass it on to chlorophyll a.
It can be found extensively in all plants, algae, cyanobacteria, phototrophs, and bacteria. Its presence is limited to only green algae and plants.
The range of absorption lies somewhat between 430 mm to 660 mm. The range of absorption varies between 450 mm to 660 mm.
The structure includes a chlorine ring of chlorophyll with a methyl group lying in the third position. In the case of chlorophyll b, it consists of an aldehyde connected to the chlorine ring in the third position.
Chlorophyll a seems to absorb violet-blue and orange-red colour from the spectrum. Chlorophyll b absorbs only the orange-red light from the sunlight.
It emits and reflects blue-green colour. This reflects a yellow-green colour.
Chlorophyll a is highly soluble in petroleum ether, whereas it has low solubility in polar solvents. Chlorophyll b shows a high rate of solubility in both methyl alcohol and polar solvents.
It consists of a CH3 side group in the porphyrin ring. It also consists of a CHO group in addition to the CH3 group in the porphyrin ring.
Chlorophyll a has a molecular formula of C55H72O5N4Mg. The molecular formula of Chlorophyll b is C55H70O6N4Mg.
It possesses a molecular weight of 839.51 gmol. It has a molecular weight of 907.49 gmol.
The process constitutes 3/4th parts of the total chlorophyll. The process takes 1/4th parts of total chlorophyll.
It acts as the base reactive centre of the antenna array of core proteins. It is responsible for deciding the size of the antenna.

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Chlorophyll

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You may have heard about chlorophyll many times, but do you really know what it is? Chlorophyll is one of the many pigments found in plants. It is crucial for photosynthesis and gives the plant essential nutrients and energy to survive. 

  • The word is derived from the Greek words khloros, which denotes pale green, and phyllon, which means leaf. 
  • The presence of chlorophyll helps plants absorb energy from the sun’s light, but they are poor at absorbing green light
  • It usually captures the blue light and the red light of the spectrum.
  • Leaves appear green because the green light is absorbed less by the tissues present in the plant cell
  • Chlorophyll serves many important functions, including absorbing light from the environment and feeding the plant. 
  • Their sole function is to transfer this captured light energy to a particular pair of chlorophyll to the plant’s reaction centre.
  • This pair charges separation, which ultimately ends up in biosynthesis. 

Chlorophyll
Chlorophyll


Types of Chlorophyll 

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Chlorophyll has been categorized into six different types. Let us know about them.

Chlorophyll a

Chlorophyll a is the primary pigment in photosynthesis which harvests light from the sun. It can be found in all organisms which are photosynthetic in nature. 

Chlorophyll b

Chlorophyll b is the element that captures sunlight and transfers it to chlorophyll a. 

Chlorophyll c

Chlorophyll c is an important element which is found in marine algae. They have a wavelength absorption range of 447 mm to 452 mm.

Chlorophyll d

Chlorophyll d is extensively found in photosynthetic organisms that live deep underwater. 

Chlorophyll e

Chlorophyll e is a very rare pigment found in limited species of algae, such as golden algae. 

Chlorophyll f

This type of chlorophyll can be seen in aquatic organisms. They are known for the absorption of infrared light. 

Types of Chlorophyll
Types of Chlorophyll

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Things To Remember 

  • Chlorophyll is the most important component of a plant cell. 
  • This pigment assists in photosynthesis, where light energy is broken down and transformed into chemical energy. 
  • There are six different types of chlorophyll, namely: chlorophyll a, chlorophyll b, chlorophyll c, chlorophyll d, chlorophyll e, and chlorophyll f. 
  • They are of different natures and have equal importance in the plant’s food-making process. 
  • Many industries utilise synthetic chlorophyll as a food colour additive. 
  • They also serve many health benefits and can be found in many green vegetables in the form of a natural compound. 
  • Chlorophyll a and chlorophyll b are in complete contrast with each other.
  • The former absorbs violet-blue and orange-red light, whereas the latter absorbs only orange-red light. 
  • Chlorophyll b is limited to only plants and algae, whereas chlorophyll a can be found in many areas. 

Sample Questions 

Ques. Where is chlorophyll located? (2 marks)

Ans. Chlorophyll is present within the thylakoid membrane of the chloroplast. These are tiny structures located in the plant cells and the powerhouse of photosynthesis. It is found in all green plants, cyanobacteria, algae and other photosynthetic organisms. The high concentration of phytoplanktons are the reason sometimes water appears to be green in colour. 

Second Answer

Ans. Chlorophyll, the pigment that gives plants their green color, plays a vital role in photosynthesis. It resides within the thylakoid membranes of chloroplasts, tiny organelles found in plant cells. These chloroplasts act as the powerhouses of photosynthesis, capturing sunlight and converting it into energy. In fact, the high concentration of chlorophyll-rich phytoplankton (microscopic marine plants) is often the reason why some bodies of water appear green.

Ques. What function does chlorophyll serve? (2 marks)

Ans. Chlorophyll helps plant cells to capture energy and essential nutrients from the sun. It is a pigment among many other pigments which provides plants with food with the help of photosynthesis. 

Second Answer

Ans. Chlorophyll is the key pigment that enables photosynthesis in plants by capturing light energy from the sun. The molecules within chloroplasts help in the absorption of specific wavelengths of sunlight, primarily blue and red wavelengths. During photosynthesis, oxygen is released into the atmosphere.

Ques. Mention some characteristics of chlorophyll a? (3 marks)

Ans. Some important characteristics of chlorophyll a are,

  • Chlorophyll a have an absorption range of 430 mm to 660 mm
  • It is abundantly found in cyanobacteria, phototrophs, and algae
  • The pigment is associated with capturing and storing sunlight
  • It has high solubility when it comes to petroleum ether.

Second Answer

Ans. The important features of chlorophyll a are as follows:

  • Chlorophyll a is a vital pigment for oxygenic photosynthesis, where organisms produce oxygen.
  • It acts as the primary reaction centre in the light-dependent reactions of photosynthesis. 
  • The pigment captures light energy and initiates the transfer of electrons needed to produce ATP.

Ques. What are the properties of chlorophyll b? (3 marks)

Ans. Some important characteristics of chlorophyll b are,

  • Chlorophyll b absorbs only orange-red light.
  • It is soluble in methyl alcohol and polar solvents.
  • The pigment eflects a yellow-greenish colour.
  • It captures sunlight and passes it on to chlorophyll a.

Second Answer

Ans. The important features of chlorophyll b are as follows:

  • Unlike chlorophyll a, chlorophyll b selectively absorbs light mainly in the orange-red wavelengths.
  • It's more soluble in polar solvents, like methyl alcohol, compared to chlorophyll a.
  • Chlorophyll b reflects yellow-greenish light, contributing to the overall coloration of plants.
  • While it can capture sunlight, chlorophyll b primarily functions by transferring the captured light energy to chlorophyll a, which acts as the reaction center in photosynthesis.

Ques. Name the types of chlorophyll? (2 marks)

Ans. There are essentially 6 types of chlorophyll. These are Chlorophyll a, Chlorophyll b, Chlorophyll c, Chlorophyll d, Chlorophyll e, and Chlorophyll f. Each of them serves different purposes and possesses unique wavelengths. Chlorophyll a is mainly found in red and green algae, whereas chlorophyll c can be seen in brown algae and dinoflagellates.

Second Answer

Ans. Chlorophyll isn't a single molecule, but rather a family of pigments. There are six main types: chlorophyll a, b, c, d, e, and f. Each pigment absorbs light at slightly different wavelengths, allowing plants and other photosynthetic organisms to capture a wider range of sunlight energy.

Ques. Why are plants green in colour? (2 marks)

Ans. A chemical called chlorophyll is present which breaks essential compounds thereby turning them into food. It is because of the special pairs of chlorophyll working together in the tissue of plant cells. They seem to absorb the red light more due to which the green light is reflected. Therefore the plants appear to be green in colour. 

Second Answer

Ans. Plants are green in colour because they use blue and red light for photosynthesis, and the leftover reflected light wavelengths are what we see as green. It's a clever adaptation that allows them to capture energy for survival while appearing green to the human eye.

Ques. Define photosynthesis? (2 marks)

Ans. Photosynthesis is a process with the help of which green plants convert light energy into chemical energy. It is done through cellular respiration where carbon dioxide and nutrients are broken down into useful nutrients required for the plant’s growth.

Second Answer

Ans. Photosynthesis is a complex but fundamental process by which plants, algae, and some other organisms convert light energy from the sun into chemical energy. This chemical energy is stored in the form of sugar molecules, which the organisms can then use to fuel their growth, development, and various cellular functions.

Ques. Name some factors affecting photosynthesis? (3 marks)

Ans. The factors affecting photosynthesis are,

  • Light - The intensity of light is a major factor. The higher the intensity of light, the more vigorous the rate of photosynthesis. 
  • Temperature - The optimal range of temperature lies between 25 degree to 35 degree celsius. 
  • Water - Scarcity in the amount of water can affect the process of photosynthesis to a great extent. 

Second Answer

Ans. The factors affecting the process of photosynthesis are as follows:

  • Light intensity plays a major role. As light intensity increases, so does the rate of photosynthesis, up to a certain point.
  • Temperature also has a significant impact. The optimal range for photosynthesis typically lies between 25 degrees Celsius to 35 degrees Celsius.
  • Water scarcity can significantly affect photosynthesis. When water is limited, plants close their stomata (tiny pores on leaves) to conserve water. Unfortunately, this closure also restricts carbon dioxide uptake, hindering photosynthesis.

Ques. What is the role of photosynthesis? (3 marks)

Ans. Photosynthesis has a vital role to play when it comes to plant life. These are, 

  • The primary function of photosynthesis is to break down water and convert it into carbon dioxide, and carbon dioxide into sugar. In this process, sunlight acts as a catalyst and speeds up the process.
  • Tiny plant cells known as chloroplasts help contain chlorophyll within them and facilitate the growth of the process of photosynthesis.
  • The main responsibility of the process is to transform the energy of the sun and turn it into a food source for green plants. As humans, we are highly dependent on them to complete our food chain. 

Second Answer

Ans. The role of photosynthesis are as follows:

  • Sunlight acts as a catalyst, not by breaking down anything, but by providing the energy to drive the reactions.
  • Chloroplasts are tiny organelles within plant cells containing chlorophyll, the pigment that gives plants green color. 
  • Photosynthesis doesn't directly convert water to carbon dioxide or vice versa. 
  • Instead, it uses the captured light energy to convert water and carbon dioxide into sugar (usually glucose), the primary food source for plants.
  • Through this process, plants transform light energy into a usable food source. 
  • We, humans, and other animals are ultimately dependent on this plant-produced food, either directly by consuming plants or indirectly by consuming herbivores that feed on plants.

Ques. What are the four different types of plant pigments? (3 marks)

Ans. The four different types of plant pigments include chlorophylls, anthocyanins, carotenoids, and betalains. These pigments form most of the naturally derived colors from plants. As per analysis, many pigments are pH sensitive and cause degradation when exposed to incompatible pH.

Second Answer

Ans. The four different types of plant pigments include 

  • Chlorophylls: These are the green pigments essential for photosynthesis.
  • Anthocyanins: They are responsible for the reds, blues, and purples in fruits, flowers, and some leaves.
  • Carotenoids: These yellow, orange, and red pigments are abundant in carrots, tomatoes, and many other fruits and vegetables.
  • Betalains: Betalains are responsible for the vibrant red hues in beets and some flowers.

Ques. What is Calvin Cycle? (3 marks)

Ans. Calvin Cycle is a type of light-dependent reaction that is used for conversion of carbon dioxide and hydrogen molecules into glucose. The process is carried out in the stroma of plant cells. The stroma is found outside the thylakoid membrane of the chloroplasts.

  • Calvin Cycle is usually carried out during the day when NADP and ATP are found in abundance.
  • The process is responsible for storing malic acid inside the vacuoles during the night.
  • It will produce the triose phosphates, 3-phosphoglycerate, glyceraldehyde-3P, and dihydroxyacetone phosphate.
  • These chemical compounds are further synthesised into hexose phosphates fructose-1,6-bisphosphate and fructose 6-phosphate

Second Answer

Ans. The Calvin Cycle is a kind of light-dependent mechanism that produces glucose from hydrogen and carbon dioxide molecules. Plant cells' stroma are where the procedure takes place. Outside the chloroplasts' thylakoid membrane is the stroma.

  • During the day, when ATP and NADP are abundant, the Calvin Cycle is typically completed.
  • The procedure is in charge of keeping malic acid overnight within the vacuoles.
  • Triose phosphates, dihydroxyacetone phosphate, 3-phosphoglycerate, and glyceraldehyde-3P will all be produced by it.
  • These chemical substances are synthesized further to yield fructose-1,6-bisphosphate and fructose 6-phosphate, two hexose phosphates.

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