Photosynthesis & Respiration

Plants use photosynthesis to make food (sugar) and oxygen gas.

When we run around or workout, we are using stored energy. Trees use stored energy when they do not have any leaves.

A chemical reaction is when you put some things together and you get something new—like when we mixed baking soda with vinegar and made gas bubbles.

Gas is all around us and is called air. We need oxygen from the air to stay alive.

Matter flows through a system like a food chain. The Sun makes the plant grow, then a rabbit eats the plant, and then a different animal eats the rabbit.

Living things get energy from food. They use energy to move and do things. Plants need energy to grow, and all living things need energy to survive.

Photosynthesis is the chemical process in which plants and other organisms combine carbon dioxide and water, using energy from the Sun, to produce sugar and oxygen.

Cellular respiration is the chemical process that occurs when an organism breaks down the food it has stored (sugars and fats) and uses it for energy.

Some bacteria, such as cyanobacteria, go through photosynthesis and so do algae.

Plants and animals both need food to survive. Animals get their food from eating plants and other animals. Plants get their food by using carbon dioxide, water, and sunlight to make sugar.

Scientists have studied bubbles trapped in glaciers, which showed that oxygen levels a long time ago were very low. As more photosynthetic organisms started to grow, the oxygen levels started to rise. Yes, the atmosphere is still changing because we keep putting other things in the air, like pollution.

In a fishbowl, there is a fish and a plant. The fish uses oxygen from the water and releases carbon dioxide. The plant then uses that carbon dioxide, water, and sunlight to make sugar and then it releases oxygen back into the water. The gases keep getting changed over and over.