In the first section of this page, you will write a daily summary of that day's class.  For example in  your chapter 2 blog, your first entry should be titled 9/3/10.  You should then write a one or two paragraph summary of that day's lecture, outlining the major points.  In the second section, you are required to add two items (link to a website, video, animation, student-created slide show, student-created PowerPoint presentation) and one journal article pertaining to a topic in this chapter.  A one-paragraph summary must accompany each item describing the main idea and how it applies to the lecture topic.  Please see the PBWorks help guide for assistance embedding video and other items directly in the page.  I will also produce a how-to video on using tables to wrap text around items and other useful tips.  Please see the syllabus for organization and grading details.

A.  Daily Blog

9/29/10

The last lecture of our first month of Gen Bio I was on membranes, the barriers of our cells. We discussed the composition of the plasma membrane (phospholipids), and their origin in the smooth ER. We also discussed how the membrane grows and breaks down via endocytosis and exocytosis of vesicles. The discussion then moved onto glycoproteins used for identification of foreign cells, and transmembrane proteins, which are transcribed into the lumen of the ER, packaged and sent in the Golgi to the plasma membrane, as vesicles. The vesicles then fuse with the plasma membrane via exocytosis, placing the protein within. We also discussed how the plasma membrane changes in response to changes in temperature (lengthening/shortening of fatty-acid chains, cholesterol, and saturation of the fatty acids).

10/01/10

This lecture moved from discussion of membranes to membrane transport. We learned about passive and active transport, the two made distinct by the involvement of energy (passive does not require energy, whereas active does). Passive transport goes down the concentration gradient, while active transport moves against the concentration gradient through the hydrolysis of ATP. Our discussion of active transport led to the first two laws of thermodynamics: energy cannot be created or destroyed, and each reaction increases entropy, or disorder. Dr. Weber explained that equilibrium is the worst state a cell could be, and the cell must work to create an active concentration gradient to perform cellular functions.

B.  Useful Materials

1. Membrane Structure: The Fluid Mosaic Model

   This link is to an animation representing the Fluid Mosaic Model. It is simple, but it effectively details all components of the model.

2. Membrane Transport

   This is a very nice virtual lecture on membrane transport that goes through both passive transport and active transport, excellently explaining both with the aid of animations.

3. Perosome

   This article discusses the perosome, a newly discovered organelle. While it was earlier believed that secretory vesicles are incorporated into the plasma    membrane during secretion, it appears the vesicles actually fuse and dock with the perosome, excreting their contents via intravesicular pressure created through active transport of water.