1. Karen 2 & Xingwei

2. CLASS: General Biology Class Size: 40-50 Freshmen, Biology Majors  Learning Goal: ◦ Students will be able to evaluate the overall importance of the transport mechanism to normal cell functioning  Learning Outcomes: ◦ Students will be able to identify molecules that can diffuse across the phospholipid bilayer ◦ Students will be able to identify molecules that are transported across the membrane

4. What do you know about the situation? What do you need to know?

5.  In the US, 5 million people suffer from heart disease such as congestive heart failure and cardiac arrhythmias.  A cardiac glycoside such as Digitoxin, also called Digitalis is used to treat this.  In Casino Royale, James Bond is given a dose of Digitalis, however, he almost dies? WHAT’S GOING ON?!!!!!!!!!!!!!!!!!!!!!

6. http://upload.wikimedia.org/wikipedia/co mmons/f/f0/Lipid_bilayer_section.gif http://library.thinkquest.or g/C004535/cell_membran es.html

8. Phospholipids form a lipid bilayer that create a selectively permeable barrier

9. For each of the Chemical species show below. Identify whether they would be able to easily pass through the lipid bilayer or not. (3 minutes) O2O2 Oxygen Sucrose Fast NO Ions Na +, Cl - K +

10. Some chemical species can diffuse across a lipid bilayer Others can not O2O2 Oxygen Sucrose Fast NO Ions Na +, Cl - K + Non polar Large polar or charged hydrophilic

11. Cell membranes are not just made of phospholipids…. Do some molecules need proteins to cross the membrane?

12. DiffusionFacilitated diffusionActive transport Passive Movement with the Concentration gradient No Proteins involved ADP  P i H2OH2O H2OH2O ATP CO 2 O2O2 O2O2 O2O2 Outside cell Inside cell Against Concentration gradient Requires Transport Proteins

13. Cellular Conditions N2N2 LactoseCa +2 With ATP +++ No ATP ++ -- Protein Synthesis Inhibitor + -- Table 1. Transport of molecules across a cell membrane. Consider the following experiment on these different chemical species Think-Pair-Share: Which of the following enters the cell by active transport? Consider the following experiment on these different chemical species Think-Pair-Share: Which of the following enters the cell by active transport? A = N 2 B=Lactose C= Ca +2

14. http://pharmacologycorner.com/animation-showing-digoxin-mechanism-of-action-effects- at-molecular-tissue-and-system-levels/ http://pharmacologycorner.com/animation-showing-digoxin-mechanism-of-action-effects- at-molecular-tissue-and-system-levels/