What is Chlorophyll?
Chlorophyll is a plant pigment responsible for the color green, formed on the chloroplast during the photosynthesis process and plays a crucial role in creating plant’s food during this process. The sunlight is absorbed by the chlorophyll and uses the energy given for converting carbon dioxide and water in oxygen and glucose. During this process, essential carbohydrates for the plant growth and development are formed. All this process happens inside a specific organelle for performing this task, called chloroplast. As a light absorbing pigment, chlorophyll absorbs the colors red, blue and white of the light spectrum, therefore reflecting the green color.
Chlorophyll exists in two mainly forms:
– Chlorophyll A (found in all plants, algae and cyanobacteria)
– Chlorophyll B (found mostly in plants).
Type A – chlorophyll is the most important pigment in the photosynthetic process since it acts as the main electrons donor in the photosynthesis electron transport chain. Besides, chlorophyll A- transfers energy light trapped to specific photosystems (P680 and P700) present in the thylakoid membrane of the chloroplast.
In plants, chlorophyll B- acts as the secondary pigment of photosynthesis by trapping light energy and transporting the electrons to chlorophyll A.
Both chlorophyll types have a similar chemical structure, consisting in a chlorine ring with four nitrogen atoms surrounding the magnesium ion and several side chains of hydrocarbons. During autumn and winter, some plants change theirs leaves color, meaning that chlorophyll as degraded and pigments like carotenoids (with the colors red and yellow) become majoritarian and consequently more visible.
What is Chloroplast?
Chloroplasts are plants organelles with important functions for plant development and growth (fatty acids, amino acid, carotenoids and chlorophyll synthesis, sulphate and nitrate assimilation). All these abilities are possible due to a special membrane system with the capacity to perform transport functions.
Chloroplasts are plant’s characteristic organelles which exhibit prokaryotic features due to their origin. About 1000 million years ago a cyanobacterial endosymbiont was primarily acquired by a eukaryotic host giving origin to different organisms, namely green algae plants.
These organelles contain chlorophyll pigments that capture energy from the light, driving the light phase of photosynthesis. Besides, chloroplasts have the crucial enzymes and needed space to carry photosynthesis light and dark reactions. During this process CO2 and H2O produce glucose with the aid of sunlight.
Each plants cell has about 10 to 100 lens-shaped chloroplasts which have 3-10µm in diameter and 1-3µm thickness.
They have 3 membrane systems
Outer – allows molecules to pass to maintain the great conditions inside the chloroplast
Inner – allows molecules to pass to maintain the great conditions inside the chloroplast
Thylakoid – Arranged in grana, they are membranous sack that keeps the photosynthetic pigments. Grana are connected to each other via stromal thylakoids.
The chloroplast’s thylakoid membrane is the location for light reactions and ATP synthesis. This ATP is used by the stroma trapped as energy in form of carbohydrates, specifically on carbon-carbon bonds.
Chloroplast stroma is the name given to the matrix of chloroplasts, which contains DNA (cpDNA), 70s ribosomes and starch granules. The different phases of photosynthesis occur in different sites, light reactions happen in the thylakoid membrane. Dark reactions happen in the stroma. This structure contains the most important enzymes required for the process of carbon assimilation.
Difference between Chlorophyll and Chloroplast
Both chlorophyll and chloroplasts are essential for photosynthesis in plants and algae. Since chloroplasts are membrane-bound organelles, they can only be found in eukaryotes, plants and algae. On the other hand, chlorophylls can be found both in prokaryotes and eukaryotes.
In the case of eukaryotes, chlorophylls are found inside the thylakoid membrane of chloroplasts, trapping light and therefore allowing the light and dark reactions of photosynthesis.
Pigment involved in the photosynthesis process, gives the color green to plants, algae and cyanobacteria
Organelle responsible for photosynthesis
Traps electrons form light and passes it to photosystems
Provides the great conditions (enzymes and space) for the photosynthesis process
Chlorophyll can be found on the thylakoid membrane of chloroplasts
Chloroplast are in all plant, but mainly on leaves
Can be found in plants, algae and cyanobacteria
Can be found in all plants and algae
- Structure, size and shape
Groups of 10 to 100 lens-shaped chloroplasts which have 3-10µm in diameter and 1-3µm thickness.
There are several types of chlorophyll (from A to F), although A and B types are the most abundant
In nature, it’s possible to find types of chloroplasts, in algae and plants
Chlorophyll is present in the chloroplast, hence the chloroplast is part of the plant cell
Chlorophyll is located inside the chloroplast, while chloroplasts are located in all plant cells, especially in leaves.
Chlorophyll is responsible for the color green in plants because it reflects this color and absorbs red and blue
Chloroplasts are essential in the photosynthesis process and carbon-assimilation reactions
There are two mainly types of chlorophyll, A and B
Chloroplasts are present in plants and algae, chlorophyll is found in all plants, algae and cyanobacteria
Since chlorophyll is a pigment, it doesn’t contain any DNA, on the other hand chloroplasts have their own DNA, called cpDNA