The word equation
What goes in and what comes out.
A short way to write it
Scientists write photosynthesis as a word equation. One side shows what goes in. The other side shows what comes out.
Which pair do you think goes in?
What this lesson covers
The idea
Carbon dioxide + Water → Glucose + Oxygen, in the presence of sunlight and chlorophyll; the glucose, a simple carbohydrate, is an instant source of energy and is later converted into starch for storage.
A short way to write it
Scientists write photosynthesis as a word equation. One side shows what goes in. The other side shows what comes out.
Which pair do you think goes in?
- Carbon dioxide and water
- Glucose and oxygen
- Starch and sunlight
Build the equation
Tap a name, then tap the box where it belongs.
Carbon dioxide + Water → Glucose + Oxygen
Plants take in carbon dioxide and water. They produce glucose and release oxygen. Sunlight and chlorophyll are needed.
Carbon dioxide + Water → Glucose + Oxygen, in the presence of sunlight and chlorophyll; the glucose, a simple carbohydrate, is an instant source of energy and is later converted into starch for storage.
- Name | Goes in or comes out
- Carbon dioxide | Goes in
- Water | Goes in
- Glucose | Comes out
- Oxygen | Comes out
Notes
Carbon dioxide + Water → Glucose + Oxygen, in the presence of sunlight and chlorophyll; the glucose, a simple carbohydrate, is an instant source of energy and is later converted into starch for storage.
Check yourself
Which two substances go in, in photosynthesis?
What is glucose?
What happens to glucose later?
What must be present for photosynthesis, as the equation says?
- Glucose and oxygen. Those are produced. Carbon dioxide and water go in.
- Water and oxygen. Oxygen is released. Carbon dioxide and water go in.
- Carbon dioxide and water — correct. Yes! These two go in.
- A simple carbohydrate — correct. Yes! It is the food produced.
- The green pigment of leaves. The green pigment is chlorophyll. Glucose is a simple carbohydrate.
- A gas released into the air. The gas released is oxygen. Glucose is a simple carbohydrate.
- It is released as a gas. Oxygen is the gas released. Glucose is converted into starch.
- It is converted into starch for storage — correct. Yes! Starch is the stored food.
- It turns into chlorophyll. Glucose is converted into starch for storage.
- Iodine and caustic soda. Those are used in experiments. The equation needs sunlight and chlorophyll.
- Darkness and oxygen. Photosynthesis needs sunlight and chlorophyll.
- Sunlight and chlorophyll — correct. Yes! These are written over the arrow.