Steven P. Wrenn, Ph.D. Drexel University

2. Cardiovascular disease is the primary cause of mortality

3. Normal Coronary Artery Severe Coronary Atherosclerosis

4. How can you detect cholesterol nucleation? Make vesicles with fluorescent analogs of cholesterol and fluorescent phospholipids. Measure their fluorescence intensities before enzymes are added, and after using a steady-state fluorescence spectrophotometer. What do these analogs look like?

8. How do enzymes cause aggregation of vesicles? The enyzme phospholipase C cleaves the hydrophilic head off of the phopholipid, leaving only the hydrophobic tails. The hydrophobic part of the vesicles are attracted to each other, causing aggregation. This is what happens to LDL in the arteries. This aggregation leads to an inflammatory response, the macrophages engulf the LDL and cholesterol nucleates causing plaques in the arteries.

11. Sphingomyelinase Is another enzyme that cleaves the head from sphingomyelin, a lipid found in the membrane. Again the hydrophobic areas of the vesicles are attracted to each other and cause aggregation. Since the particles are now much larger than before the enzyme was introduced, this shows up as increased absorbance on the spectrophotometer.

13. Absorbance vs. Concentration

15. Unit Long Understanding Goals What do the components of the cell membrane look like? What elements make up these components? What are the properties and functions of these components?

16. Unit Long Understanding Goals What happens to excess cholesterol in the diet, and what are the roles of LDL and HDL? What foods will raise HDL levels and lower LDL? What enzymes cause nucleation of cholesterol and how do they work? How does the aggregation of LDL start the inflammatory response?

17. Introductory Performance In groups, using molecule building kits, the students will build models of phospholipids On line investigation of properties of phospholipids and how they form cell membranes and vesicles. Simple investigation of one enzyme that breaks down phospholipids to see if group can hypothesize about what is happening.

18. Guided Inquiry Using phospholipase C and phospholipid vesicles,the students will complete a lab using a Spec 20 to gather data on absorbance vs. concentration and absorbance vs. time to show vesicle aggregation Complete 1-2 pg report on role of HDL and LDL in cholesterol transport Keep a journal for a week on what they eat,and analyze the saturated fat. In a group, suggest ways to reduce levels of LDL and raise levels of HDL in their diets. Write a one page reaction paper on guest speaker from Drexel explaining how the aggregation of LDL triggers the inflammatory response that causes plaque formation in arteries.

19. Culminating Performance Students working in pairs or groups, create a model, a presentation on PowerPoint, a Web page or a pamphlet using Pagemaker to present their knowledge to adults/students whom were not in the class

20.