In the alphabet the basic unit is a letter. In all living things the basic unit is a cell. The smallest living things are singe cells that carry out all of the process of life by themselves. Two of the basic functions of cells are getting energy and getting rid of waste.

Getting Energy

When you are getting alittle sleepy during the day what do you do. Many people grab a candy bar or a soda. Why? One reason is the both contain sugar. We call this energy. Animals obtain energy by eating things. Anything that animals eat they digest and convert to sugars. Sugar is the basic source of energy. Whatever you eat for energy gets converted to sugar. Now, we also need other things like proteins, fats, vitamins, minerals and fiber. All of these things that we eat and need are actually used at the level of a cell. Each cell in your body needs energy and when you eat foods your body breaks it down int smaller and smaller pieces until your cells can bring them into your body through the process of osmosis. This entire process of getting food and breaking it down and your cells using the energy is called digestion and respiration.
Plants also need energy but you don’t often meet a sagebrush getting a candy bar at the vending machines. Plants get their energy differently than you or I. Plants have a special chemical in their cells called chlorophyll. This chemical and a cell organelle called a chloroplast allows plants to use carbon dioxide, energy from sunlight and water to make sugar. This process is called photosynthesis.

Getting rid of waste

You may have noticed that some of your friends can make unusual body noises that are odoriferous. That is part of getting rid of waste. Plants do the same thing but there is no odor. When plants go through the process of photosynthesis they give off Oxygen as part of their waste. We use oxygen as we go through the process of respiration and one kind of waste that we need to get rid of is Carbon dioxide which we breath out. We have other kinds of waste and it is by products of the cell process that result in the odoriferous releases from our bodies. Each cell in our body goes through these process of obtaining energy and releasing waste. Our circlulatory system helps move those cell wastes so they can be removed by our kidneys and be removed from our bodies.

Discussion ideas
Does it make sense that cells all use energy and release waste?

What are some other forms of energy?

Can you think of any living things that don’tuse energy?