Name(s):___________________________________________________________________________________________
Lipids
Lipids are a diverse group of macromolecules that include fats, oils, waxes, and steroids. Fats are assembled from
monomers. One type of the monomer used to build a fat is a fatty acid. Fatty acids are classified as saturated,
unsaturated and polyunsaturated. Compare the saturated and unsaturated fatty acids shown below.
1. What is the difference between saturated fatty acids and unsaturated fatty acids?
2. Can you predict what a polyunsaturated fatty acid would look like?
3. What functional groups do you see in the fatty acids?
4. What property does this functional group give the fatty acid? Hint it is in the name of the structure.
Step 1: Use the diagram above and molecule packet #2 to build 3 fatty acids (2 saturated and 1 unsaturated). In the
molecule packet you will find the following:
 White tubes (71) these represent to covalent bond formed between two atoms.
 Black model pieces (21) these represent carbon atoms.
 White model pieces (42) these represent hydrogen atoms.
 Red model pieces (9) these represent oxygen atoms.
Follow the diagram above as you join carbon atoms, hydrogen atoms, and oxygen atoms to build your own fatty acid
molecules.
Glycerol
Step 2: Glycerol is another type of monomer used to build fats. Use the diagram above and molecule packet #2 to build
1 glycerol molecule. Follow the diagram as you join carbon atoms, hydrogen atoms, and oxygen atoms to build glycerol.
5. What functional group do you see in glycerol?
Step 3: Use the diagram above and the molecules that you made to assemble a triglyceride.
6. What type of reaction is this?
7. What molecules are produced from this reaction and how many of each type are produced?
8. How are lipids classified? Hint: How do lipids react with water?
Circle One:
Polar & Hydrophillic (water loving)
Nonpolar & Hydrophobic (water hating)
9. A triglyceride is a fat. What is the function of the fat?
Phospholipid
Step 4: Use the diagram of the phospholipid (above) to answer for the following questions.
10. How does a phospholipid differ from a triglyceride?
11. How is a phospholipid similar to a triglyceride?
12. Where in a cell would you find phospholipids (every cell has lots of them)?
13. What type of reaction do you think is involved in building a phospholipid?
14. Do you think water is a by-product of making phospholipids? If so, how many would be produced?
Step 5: Use the diagram of common steroids above to answer the following questions.
15. How are cholesterol, progesterone and testosterone similar?
16. How are cholesterol, progesterone and testosterone different from each other?
17. Like all lipids, steroids are hydrophobic. What does this tell you about steroids and water?