Passing Through Karen 2 Xingwei CLASS General Biology
Passing Through Karen 2 & Xingwei
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
BOND, JAMES BOND http: //www. youtube. com/watch? v=_y. Nntw. Sj. Owo
What did you observe? What do you know about the situation? What do you need to know?
Previously…on “Passing Through” - Fats, Fats and more Fats � 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? !!!!!!!!!!!
Phospholipid Bilayer in Cell Membrane http: //library. thinkquest. or g/C 004535/cell_membran es. html http: //upload. wikimedia. org/wikipedia/co mmons/f/f 0/Lipid_bilayer_section. gif
Phospholipids form a lipid bilayer that create a selectively permeable barrier
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) Fast NO Oxygen O 2 Sucrose Ions Na+, Cl. K+
Some chemical species can diffuse across a lipid bilayer Others can not Non polar Large polar or charged hydrophilic NO Fast Oxygen Sucrose O 2 Ions Na+, Cl. K+
Cell membranes are not just made of phospholipids…. Do some molecules need proteins to cross the membrane?
Diffusion O 2 Outside cell Inside cell O 2 Facilitated diffusion CO 2 CO CO 2 2 H 2 O CO 2 H 2 O Passive Movement with the Concentration gradient No Proteins involved Active transport ATP ADP Pi Against Concentration gradient Requires Transport Proteins
Consider the following experiment on these different chemical species Think-Pair-Share: Which of the following enters the cell by active transport? Table 1. Transport of molecules across a cell membrane. Cellular Conditions N 2 Lactose Ca+2 With ATP + + + No ATP + + -- Protein Synthesis Inhibitor + -- -- A = N 2 B=Lactose C= Ca+2
SODIUM POTASSIUM PUMP • http: //pharmacologycorner. com/animation-showing-digoxin-mechanism-of-action-effects-at -molecular-tissue-and-system-levels/
ACTION OF CONTRACTION IN THE HEART
Na+/K+-ATP-ase
Digitalis Attached to the Na+/K+-ATP-ase
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