Biomolecules in Cells

Contributor: Hannah Brooks. Lesson ID: 12128

Most people can choose from various foods, some good for you, some not. Food consists of stuff that cells need to keep you well. Learn the components' fancy names and why you need them!


Chemistry, Life Science

learning style
personality style
Grade Level
Middle School (6-8)
Lesson Type
Dig Deeper

Lesson Plan - Get It!

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Most animals, especially pets, seem to eat the same foods over and over.

Watch this clip from the movie Charlotte's Web to see Templeton the rat enjoy all kinds of food!

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You certainly don't eat the way Templeton does, but humans do eat various foods.

  • Why do we eat from different food groups?
  • Is it to keep us from getting bored?
  • What did you have for your latest meal?
  • Was it well-balanced or only one food group?

Learn why eating different foods and nutrients is important. These nutrients comprise biomolecules used in our body’s cells.

Before diving into the four biomolecules, you must understand a little about carbon. Carbon is an element on the periodic table with six protons, electrons, and neutrons.

Carbon can bond with many other elements to create both compounds and molecules.

Compounds and molecules with both carbon and hydrogen are called organic, and all four of the biomolecules you will learn about today are organic. These organic molecules make life on the earth possible and support the growth and development of living things.

As you learn about the four major biomolecules, complete the Biomolecules Graphic Organizer found in Downloadable Resources in the right-hand sidebar.

Each group of biomolecules is made up of a different monomer, or building block. These monomers bond together to create polymers, or long chains of repeating molecules.

Start by identifying the monomer for each biomolecule.

As you watch the video below, complete the graphic organizer.

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Review what you've learned!


Carbohydrates, or sugars, have three groups: monosaccharides, disaccharides, and polysaccharides.

Examples of each group include glucose, sucrose, and starch.

  Lipids are also known as fats and include foods like peanut butter and oil.
  Nucleic acids are probably not the most interesting biomolecule, but they sure are important! Without nucleic acids, we could not replicate cells, pass on genetic information, or give instructions to body parts.
  Proteins make up meats and beans. They provide our cells with structure and support. There is a very special class of proteins, called enzymes.


Learn more about enzymes with this next video.

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Answer the following questions on the back of your graphic organizer.

  • What are enzymes?
  • Why are they so important for cellular function?
  • What are two examples of enzyme functions?
  • What does an enzyme with an active site and a substrate ready to bond look like? (Make a sketch.)
  • What does the lock and key model mean?
  • What do enzyme names end in?

If you feel like you missed something important, check out this video that reviews all four biomolecules.

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It does matter when your adults try to get you to eat healthily! We need to get all four biomolecule sub-units in our day-to-day meals for our cells to function correctly.

  • Which biomolecule do you think is most important in your diet?
  • Why did you pick that biomolecule?
  • Which biomolecule is most important in cell function?

All biomolecules are important components of a well-balanced diet, and they are all needed to ensure the cell can function properly.

In the Got It? section, go more in-depth and practice identifying biomolecules based on structure and function.

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