When you get hungry, what do you do? You might decide to raid the refrigerator or try to convince your mom to take you to a fast food restaurant. You do those things because you are a heterotroph (or consumer). Heterotrophs are organisms that need to get their energy from the foods they eat. Humans and animals are heterotrophs — so are parasites like fleas, ticks, and tapeworms!
Conifers, like other green plants, can't just reach in the fridge for a quick snack. They have to make their own food. Green plants are called autotrophs (or producer). Autotrophs use light energy from the sun to produce the food they need. To understand how this works, we need to learn about photosynthesis.
Sometimes you can learn a lot about something by looking closely at the word that describes it. Photosynthesis is one of those things. The word photosynthesis is made up of a prefix (photo) and a root word (synthesis).
Now that we know how the word is put together, we can look at a formal definition of photosynthesis. A dictionary says photosynthesis is
Photosynthesis is a process. It's a set of steps that happen in a certain order inside the cells of green plants. Let's think of photosynthesis as a recipe — the plant version of a making a batch of chocolate chip cookies!
Before you begin cooking, you need to be sure you have all of the ingredients. Then you can get started! It's the same with plants.
What might a recipe for photosynthesis look like?
The recipe above is a very simple way to think about photosynthesis. It's really a very complicated process and scientists are still learning exactly how it works.
About the Ingredients
Plants need the right ingredients to produce the carbohydrates they need. The definition of photosynthesis tells you that sunlight is needed for energy. Now, let's look more closely at the other ingredients.
REAL TREES and other green plants are active food factories. They use photosynthesis to create the food they need to grow and reproduce. Without them, other organisms would be without a food source.