So all life on earth depends on plants. We would not be here if plants were not on the planet. That's because plants can turn the energy in sunlight into a chemical form, sugars, by an amazing process called photosynthesis.
This process happens inside plant cells in the chloroplast, these little organelles inside plant cells, where this amazing reaction takes place. They have inside there a special pigment called chlorophyll, and the chlorophyll traps that energy that's coming down from the sun in the UV light, and it uses that energy to turn water and carbon dioxide, these two very, you know, inert, not particularly exciting things that are pretty abundant on the planet, we've got lots of carbon dioxide in the air, we've got lots of water around, But they can turn those using that energy into glucose. Now glucose, sugar, is stored chemical energy. So that's an exciting process because then that can be passed up the food chain. So if an animal eats the plant, it gets that sugar.
And if other animals eat those animals, they get that sugar. So all the energy that's stored on this planet has come from this one process, photosynthesis, that the plants are doing. Now you need to know the word equation for this and the chemical symbol equation.
The word equation, you take your carbon dioxide, you take your water, arrow, never do an equals in a chemical equation like this, and it goes to glucose, and then there's oxygen given off as waste, which is also another great thing about photosynthesis, because obviously we need oxygen. So not only are they providing energy for us, they're also providing oxygen for our atmosphere. You need the sun, you need the chlorophyll, but they don't go in the equation. You can write them over the arrows, but they're not reactants and they're not products. Now the chemical symbols, it's easy to remember the symbols for carbon dioxide, CO2, water, H2O, and oxygen O2.
Glucose has a nice pattern to it, C6H12O6. Some people then struggle with how to balance that equation. Now you don't need to worry about trying to work out how all the seven carbons here and here over here. It's simple. There's an easy way to remember it, which is the number of the devil.
The number of the devil, 666. Put a 6 in front of everything apart from the glucose. 6-CO2, 6-H2O and 6-O2. Now once the plant has made this glucose, it can then turn it into all sorts of things.
The plant can store it as starch, it can turn it into cellulose to make more cell walls, it can use it itself to do respiration to release energy that it needs. It can store it as fruit in the form of sucrose, or it could use some nitrates from the soil and then make proteins in order to grow even more. So this glucose is really the precursor to everything that the plant needs.