Organisms and the Environment

2. Organisms and the Environment

3. Chapter Four: Physical ScienceConnections • 4.1 Elements and Compounds • 4.2 The Compounds of Life • 4.3 Physical Variables

4. 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.

5. 4.2 Carbon compounds and cells • Carbon compounds in living things include: carbohydrates, proteins, lipids and nucleic acids.

7. 4.2 Carbohydrates, fats and proteins • Carbohydratesare energy-rich compounds made from carbon, hydrogen, and oxygen. • Cells use carbohydrates to get and store energy. • Carbohydrates are also called sugars or starches.

8. 4.2 Carbohydrates • Plant cells store energy as starch. • Rice, potatoes, and wheat are plant starches.

9. 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?

10. 4.2 Proteins • Proteinsare very large molecules made of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur. • Protein molecules are made of smaller molecules called amino acids.

11. 4.2 Nucleic acids • Nucleic acidsare 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.

12. 4.2 DNA • Some scientists refer to DNA as the “blueprints” for life. What is a blueprint and why might scientists use this “analogy”?

13. Investigation 4A Carbon Dioxide and Living Things • How is carbon dioxide important to living things?