Lipid Study Guide
1. The elements that make up lipids are __________, ____________, and ___________.
2. Fats, a type of lipid, are made up of fatty acid chains and glycerol.
a. How many fatty acid chains are in one fat?
b. How many glycerol molecules are in one fat?
The two ends of a fatty acid molecule have different properties – one end is polar and the other is
nonpolar. Molecules that are polar attract water and are called hydrophilic (hydro=water; philic =
loving). Molecules that are non-polar repel water and are called hydrophobic (phobic = fearing). Think
about what happens when water and oil mix. This property will be very important when we discuss
cell membranes.
3. What is the different between a saturated fat and an unsaturated fat? Be sure to discuss the bonds in
the fatty acid chains when answering the question.
4. Contrast the characteristics of saturated fats and unsaturated fats using a T-chart.
5. Why are lipids a good source of energy for living organisms?
6. Fill in the chart below for the three different categories of lipids.
Category
Components (Parts)
Properties
Examples
Triglycerides
Phospholipids
Waxes
7. Steriods are another class of lipids formed by four rings of carbon that are fused together. One of the
most important steroids is cholesterol. Cholesterol is a building block of the cell membrane and it is an
important precursor to many hormones. Hormones such as testosterone and estrogen are also steroids.
In the box below, draw a molecule of cholesterol.