How is Light Energy Converted into Chemical Energy during Photosynthesis?

(Last Updated On: January 19, 2021)

The participation of a few significant elements (water, sunlight, chlorophyll) altogether causes a chemical reaction, and then the light energy converts into chemical energy.

Plants are called autotrophs. That means they produce their food, take it and ensure survival and growth. The life-cycle of plants in scientific words is known as photosynthesis. The plant’s procedure of cooking meals is the scientific version of converting light energy into chemical energy.

Here, you will know how a photosynthesis process occurs and why it is crucial for both plants and living beings. Let’s learn more!

Elements of Photosynthesis

Only the presence of each element can ensure to perform complete photosynthesis. So let’s have a look at every individual ingredient and the importance.

a) Sunlight

Sunlight is the primary energy source of any plant. With its help, the photosynthesis process goes on, and the plants could arrange their meal. When plants can have plenty of sunlight around, the specific seasons are visible by plants’ vigorous growth.

Similarly, when the sunlight is just out of reach, the plants do not get enough light to produce enough food for them. The result of it is broadly noticeable in the winter season. Many indoor gardeners use artificial grow light for indoor plants where sunlight not reach.

b) Water

Water is a mixed compound of Hydrogen and Oxygen. Both of these molecules together have responsibilities to participate in performing photosynthesis.

The plant’s sugar compound has hydrogen, oxygen, and carbons. Now you might understand where they come from. Though the final processing and getting the actual result has a long way to get the sugar, the reason for photosynthesis.

c) Carbon Dioxide

Plants receive carbon dioxide from the air. While the carbon dioxide gas has hampered our healthy living on earth at the same time, it holds the most importance in producing the energy for plants to live and grow.

Indeed, surprises of nature!

The sugar or glucose, you may say, has several carbons in each molecule. To create enough glucose for the plant cells, the amount of carbon dioxide they need is enormous.

d) Chlorophyll

Now that we have discussed all the external resources at work to perform photosynthesis, it’s time to know a bit from the internal resource that hosts all the processes and get the benefits.

Chlorophyll is nothing but a molecule in the plant’s leaf. But that is where all the complex functionalities of photosynthesis take place. Chlorophyll can absorb light of a limited region of spectrums.

So it attracts all the outer elements, and with the assistance of each other, they finally accomplish the task.

Production from Photosynthesis

After using all the elements and going through the complex functions, photosynthesis produces these two following products.

A. Carbohydrate

Carbohydrates are those essential products that the plant restores from photosynthesis. There are several procedures to go through before having stable sugar or glucose for plants. After carbon-fixation, all the carbons in use for photosynthesis form as an energy source for plants.

The excess carbohydrates can be kept stored in different forms, such as starch or glycogen. The plants can reuse them whenever they feel the need.

B. Oxygen

In the whole process, producing oxygen was never the goal. Oxygen is a by-product that originates from the photosynthesis process but not usable for plants, so they release it to nature.

You have already seen the elements to perform photosynthesis. The atoms of water (H2O) are interlinked, and that is how, when it is used in photosynthesis, the molecules of oxygen stay unchanged while the hydrogen takes part in producing sugar for plants.

Analyze step-by-step conversion of light energy to chemical energy. By now, you should have explicit knowledge of each element to be used and produced in photosynthesis. To know the procedure step by step, clear your mind, and concentrate on the coming section.

Step-1. The Entry of Carbon Dioxide (CO2)

A plant’s leaf has epidermal pores, and they are responsible for transferring the gases or water vapours it collects from nature.

To conduct photosynthesis, the carbon dioxide already in the climate enters the leaf via stomata. The stems or epidermal pores, later on, transfer the co2 to the host where the photosynthesis would occur.

Step-2. Consumption of Water (H2O) in Leaves

Plants can only soak water from the soil. And then it makes sure to supply the water top to bottom with the stems.

Initially, the roots of any plant soak water from the soil. Through the stems, the water reaches all the leaves on that plant so that every single one can participate in photosynthesis with other elements.

Step-3. Absorption of Light

When we suppose all the elements are present in a leaf, the photosynthesis process only starts while the sunlight falls onto it.

The chlorophyll in leaves attracts the sunlight and absorbs all the needed spectrum to split the ingredients and produce sugar. The sun’s duration and the availability of other elements determine how long the process would continue to run.

Step-4. Main Production

Finally, all the primary molecules break and form in carbohydrates to serve the plants at this stage. Whereas extra atoms of oxygen released to nature through stomata as a waste product.

Here another procedure establishes the reduction of the electrons and forms a result. If you are ready to dive deeper, let’s know more about it.

The Calvin Cycle

The Calvin cycle occurs in the stroma. It divides the fixed compounds with the help of ATP NADPH, the light reactors. This procedure is known as light-independent as it doesn’t require direct light.

The Calvin cycle accomplishes its task in three different steps. The first step is Carbon Fixation, where the five-carbon molecule combines with RuBP (Rubisco) and turns into six-carbon molecules. Later on, it splits into two molecules, which is a compound of three-carbons each.

In the second step, by reducing ATP and NADPH electrons, the two molecules of three carbons convert into sugar. Here the 3-Phosphoglyceric Acid (3-PGA) converts into Glyceraldehyde-3-Phosphate (G3P) – Sugar mainly.

In the last step, all the separate atoms reproduce the molecules, form carbohydrates, and restore the extra glucose as starch, fat, or oil or recycle to use in another way.

Photosynthesis Formula/Equation

6CO2 + 6H20 + (energy) → C6H12O6 + 6O2 

Carbon Dioxide + Water + Sunlight → Glucose + Oxygen

Why Is Photosynthesis Important to Ecological Balance?

A balanced ecosystem has so many necessities why you should not take it lightly. However, we are well aware of that and it is still widely visible how everyone ignores it, as we will survive without plants or oxygen.

Now that I have your attention allow me to show you an extensive overview.

a) Reproduction of Oxygen

Photosynthesis is the most common source of getting adequate oxygen for all living beings. Oxygen gets off as a waste product from photosynthesis and spreads in nature. It enables the air to have enough oxygen for our respiratory system.

There is no alternative source of getting sufficient oxygen for all living creatures other than the photosynthesis process. Thus, who would dare to mess the balance by putting the life of humankind at stake?

b) Eliminating Carbon Dioxide

Carbon dioxide, on the contrary, has only harm to offer humans and animals. You must know we breathe-out carbon dioxide and inhale oxygen. The plants are designed to do the opposite.

By following our system, unconsciously, we have contributed to nature. But it can be hampered while both sides won’t have a similar amount of oxygen and carbon dioxide to offer.

c) An Energy source for Heterotrophs

Heterotrophs are those who cannot produce their meal like the autotrophs (Plants, Algae, Iron Bacteria) does. The autotrophs use sunlight, water, carbon dioxide and make their food.

The autotrophs are a massive energy source for the heterotrophs. The fruits, leaves and other edible portions fill the hunger of humans and animals also it has immense nutritions that everyone needs to live a healthy life.

Would you still think of an alternative to photosynthesis?

d) Balancing Food Chain

As you have read, plants do not only concentrate on their survival by performing photosynthesis. It does several other benefits to us, and balancing the food chain is another of them.

Plants are supplying foods for humans and animals and, at the same time, responsible for making their meals by photosynthesis. Numerous consumers are interlinked in this food chain. Any fall on a specific group may create unwanted situations for other livings.

e) Additional Acquisition

The plants have an indirect contribution to reducing high temperatures. Excess carbon dioxide in the air raises the warmth in the climate. Thereby, more plants performing more photosynthesis can consume extra carbon gases, which offers a cold and calmer environment.

Frequently Asked Questions

What is Photosynthesis?

Photosynthesis is a procedure of converting light energy into chemical energy. It occurs with the combined participation of sunlight, water, and carbon dioxide and takes place at the plant’s leaves. The whole process is conducted to generate food (carbohydrate) for plants, essential in their growth and survival, while some ecological terms also have been taken care of.

What is the name of the sugar formed during photosynthesis?

The sugar forms during photosynthesis are known as “Glucose.” Thousands of glucose molecules are connected to build carbohydrates.

What are the three things used to make glucose in photosynthesis?

A plant receives carbon dioxide from air, sunlight, and water from nature to complete the photosynthesis process. Glucose is the product a plant gets from the process.

What do plants do with extra glucose?

Plants store the extra energy as starch and use them for multi-purpose. The excess glucose can be in the form of oil and fat and blend with fruits as a sucrose form. The primary task of starch is to structure plant cells.

How is energy transferred to photosynthesis?

By using three natural elements, photosynthesis converts light energy into chemical energy. To be more precise, ATP and NADPH are the two chemical molecules that transport energy.

Does photosynthesis produce oxygen?

Oxygen is produced as a by-product whenever plants perform photosynthesis. Consuming co2 and releasing o2 has maintained balanced ecological terms in both worlds of plants and living beings.

Do plants steal oxygen at night?

Most plants seem to consume minimal oxygen at night but do not release as photosynthesis cannot occur at night. However, Aloe Vera plants are exceptional. They filter the air from toxins and release oxygen at night.


Apart from other benefits, the plants offer us food to eat and oxygen to breathe via photosynthesis is unavoidable. Whereas carbon dioxide consumed by plants befalls nature on another height of supremacy, therefore, how much we know continuous science is happening around us.

However, to keep the balance in the ecosystem and our survival, never-ending photosynthesis is a must. For which, no numbers of plants on earth will ever be enough to draw the secure line. Undoubtedly, the more, the better.

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