1. Chemical Compounds in Cells Chapter 3 Section 3

2. What do the below objects all have in common?

3. An element is a pure substance where all the atoms in a sample of matter have the same identity, and cannot be broken down into simpler substances. For example all of the elements in the periodic table.
Compounds are made from atoms of two or more elements that are combined.

4. A substance can be either an element or a compound.
What compound does the above molecules represent?

5. Most chemical reactions that take place within cells could not take place without water.
Many compounds in living things contain the element carbon, Compounds that do not contain carbon are called inorganic compounds. Water and sodium chloride are familiar examples of inorganic compounds.

6. A carbohydrate is an energy rich organic compound made of the elements carbon, hydrogen, and oxygen. Sugars and starches are carbohydrates.

7. Lipids contain more energy than carbohydrates, and are also made of carbon, hydrogen, and oxygen. Fats, oils, and waxes are all lipids.

8. Proteins are large organic molecules made of carbon, hydrogen, nitrogen, and in some cases sulfur. Foods that are high in proteins include meat, eggs, fish, nuts, and beans.

9. Protein molecules are made up of smaller molecules called amino acids
Protein molecules are made up of smaller molecules called amino acids. There are 20 common types of amino acids, that can combine to form thousands of different proteins.

10. An enzyme is a type of protein that speeds up a chemical reaction in living things.
Without enzymes many chemical reactions that are necessary for life would either take too long or not occur at all.

11. Examples of Nucleic Acids are DNA and RNA
Nucleic Acids are very long organic molecules made of carbon, oxygen, hydrogen, nitrogen, and phosphorous. Nucleic acids contain the instructions that cells need to carry out the functions of life.
Examples of Nucleic Acids are DNA and RNA
DNA stands for deoxyribonucleic acid
RNA stands for ribonucleic acid