2. 4.2 Carbon compounds and cells
Life as we know it is carbon based.
A carbon atom can form chemical bonds with other carbon atoms in long chains or rings.

4. 4.2 Carbohydrates, fats and proteins
Carbohydrates are energy-rich compounds made from carbon, hydrogen, and oxygen.
Cells use carbohydrates to get and store energy.
Carbohydrates are also called sugars or starches.

5. 4.2 Carbohydrates Plant cells store energy as starch.
Rice, potatoes, and wheat are plant starches.

6. 4.2 Lipids
Lipids are made by cells to store energy for long periods of time.
Lipids include fats, oils, and waxes.
Can you think of examples of lipids in plants or animals?

7. 4.2 Proteins
Proteins are very large molecules made of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur.
Protein molecules are made of smaller molecules called amino acids.

8. 4.2 Nucleic acids
Nucleic acids are compounds made of long, repeating chains called nucleotides.
DNA is a nucleic acid that contains the information cells need to make all of their proteins.