Introduction

All of the energy that exists within the ecosystems on Earth originated with the Sun.

This energy must first be converted from light energy into chemical energy, and plants use a process called photosynthesis to achieve this.

We call plants producers because they produce all of the planet’s food.

Plants don’t consciously make food for consumers, but make food for themselves to grow and function.

Thankfully, plants make so much food from the sun, that there is plenty of energy left to support all other organisms.

When plants receive sunlight, they use the energy to make a sugar, called glucose. Glucose is a molecule made up of three elements: carbon, hydrogen and oxygen.

The elements needed to make glucose come from the water the plant takes in from the ground and the carbon dioxide that it takes in from the air.

During this chemical reaction inside the plant, oxygen gas is also made. It is released by the plant back into the atmosphere.

This is helpful to animals, like us, that breathe in oxygen to survive.

Let’s take a look at the process of photosynthesis written as a chemical equation and use it to review.

Plants take in carbon dioxide and water and use the energy of the sun to convert it into glucose and oxygen.

This chemical reaction takes place in tiny structures, called chloroplasts, inside plant cells.

Chloroplasts contain a green pigment, called chlorophyll, that absorbs the sun’s energy.

That is why plants are green!

Because of chlorophyll, plants are able to produce the glucose and oxygen that cells, like those in this caterpillar, need to function and grow.

Like all other organisms, our cells require glucose and oxygen that plants produce.