The key difference between chlorophyll and carotenoids is that the chlorophyll is a family of green colour pigments primarily used for photosynthesis in photosynthetic organisms while the carotenoids are a group of yellow to red colour pigments including carotenes and xanthophylls that are accessory pigments.
The pigment is a colourful chemical compound that reflects a certain wavelength of visible light. It is responsible for giving the characteristic colours to many objects including flowers, paints, fruits, leaves, corals, etc. A specific pigment absorbs a particular wavelength of visible light and reflects a different wavelength that is visible to our naked eye. In photosynthetic organisms, green colour pigments called chlorophylls play a major role in the process of photosynthesis. Another pigment group called carotenoids is also able to absorb light, but they cannot involve directly with the photosynthetic pathway. They are yellow, orange and red colour pigments.
CONTENTS
1. Overview and Key Difference
2. What is Chlorophyll
3. What is Carotenoids
4. Similarities Between Chlorophyll and Carotenoids
5. Side by Side Comparison – Chlorophyll vs Carotenoids in Tabular Form
6. Summary
What is Chlorophyll?
Chlorophyll is a group of green colour pigments present in plants and other photosynthetic organisms. In fact, chlorophylls are the primary pigments of photosynthetic organisms including plants and algae. These pigments are capable of capturing light energy from sunlight and produce carbohydrates. Generally, this family has several types of chlorophyll pigments such as chlorophyll a, b, c and d.
Among the several types of chlorophyll pigments, chlorophyll a and b are the most common pigments that mainly involve in the photosynthesis. Chlorophylls absorb yellow and blue colour wavelengths from the electromagnetic radiation and reflect green. Hence, they are visible to us in reflecting colour that is green.
Figure 01: Chlorophylls
Structurally, chlorophyll molecule contains a porphyrin ring composed of carbon, hydrogen, nitrogen and oxygen molecules surrounding a central metallic ion; the magnesium.
What is Carotenoids?
Yellow, orange and red colours that we see in everywhere are due to the pigments called carotenoids. They are the chemical compounds that reflect these colours. Also, there are two main types of carotenoids; namely, they are the carotenes and xanthophylls. Carotenes are the orange to yellow colour pigments while xanthophylls are the yellow colour pigments. The typical colour of carrots is due to the beta carotenes that it contains. On the other hand, the typical colour of tomato is due to the lycopene which is another carotenoid pigment.
Structurally, carotenoids contain two small six carbon rings and a long carbon chain. Therefore, they are not soluble in water. Instead, they are soluble in fat. Also, in photosynthetic organisms, carotenoids play a role of accessory pigments. Though carotenoids are unable to transfer absorbed light into the photosynthetic pathway directly, they can transfer their light to chlorophylls and assist the photosynthesis. Hence, they are present within the chloroplasts and even in cyanobacteria, as well.
Figure 02: Carotenoids
Moreover, carotenoids are popular as important antioxidants as well. They are capable of deactivating free radicals; hence, provide health benefits. Furthermore, they have an anticancer property. Also, some carotenoids can convert into vitamin A, which is vital for the good vision and growth and development. Not only that, carotenoids are popular as anti-inflammatory compounds that prevent inflammatory conditions. Besides, carotenoids provide immune benefits as well.
What are the Similarities Between Chlorophyll and Carotenoids?
- Chlorophylls and Carotenoids are pigments.
- They are plant pigments.
- They are also present in chloroplasts.
- Furthermore, they are present in cyanobacteria as well.
- Also, both types of pigments can absorb light.
- Besides, both can absorb certain wavelengths of the light and reflect certain other wavelengths that are visible to us.
What is the Difference Between Chlorophyll and Carotenoids?
Chlorophylls are green colour plant pigments while the carotenoids are yellow to red colour plant pigments. Therefore, this is the key difference between chlorophyll and carotenoids. Furthermore, there are several types of chlorophylls; chlorophyll a, b, c and d while there are only two types of carotenoids. They are the carotenes and xanthophylls. Hence, it is another difference between chlorophyll and carotenoids.
Moreover, both types of pigments can absorb light. But, unlike carotenoids, only chlorophylls can transfer light to the photosynthetic pathway directly. Furthermore, there is also a structural difference between chlorophyll and carotenoids. Chlorophylls contain a porphyrin rings in their structure while carotenoids contain two small six carbon rings and a long carbon chain.
Summary – Chlorophyll vs Carotenoids
Chlorophylls and carotenoids are two types of plant pigments. The key difference between chlorophyll and carotenoids is the reflecting colours. Chlorophylls reflect green colour wavelength; hence, visible in green colour while the carotenoids reflect yellow to red colour wavelengths; hence, visible in yellow, orange and red in colours. Furthermore, chlorophylls are the primary photosynthetic pigments that involve directly with photosynthesis while the carotenoids are accessory pigments that transfer absorbed light to chlorophylls due to the inability of transferring directly to the photosynthetic pathway. There are several types of chlorophylls namely chlorophyll a, b, c, and d while there are two main types of carotenoids namely carotenes and xanthophylls. Thus, this summarizes the difference between chlorophyll and carotenoids.
Reference:
1.Szalay, Jessie. “What Are Carotenoids?” LiveScience, Purch, 15 Oct. 2015. Available here
2.“Chlorophyll.” NeuroImage, Academic Press. Available here
Image Courtesy:
1.”Leaf 1 web”By Jon Sullivan – PdPhoto, (Public Domain) via Commons Wikimedia
2.”Flower with carotenoids”By Kumaravel Marimuthu – Own work, (CC BY-SA 4.0) via Commons Wikimedia