Misconception

As I read through your introductions I am seeing a common misconception, that the reasons ions can't get across the cell membrane is due to the charged phosphate group.  This might be a small factor, but the main barrier to ions are the hydrophilic tails.

I think the problem may be due to the way the phospholipid bilayer is drawn, like below.

From this diagram it looks like the hydrophilic portions are large and act as a barrier.  But in reality the phosphate group is pretty small compared to the hydrocarbon chains.  Below is a space-filling model (closer to the real structure).

Here you can see that that portion is fairly small.  

So, to summarize, if you are going to discuss why ions can't cross the cell membrane your primary reason should be that they can't get across the lipid portion.

Transport Across the Cell Membrane Quiz Next Class (Mon/Tues)

Like the last quiz, you may bring in one 3x5 index card that has handwritten notes on one side. Squids- I forgot to give you cards.  You can bring in your own or just use a 3x5 piece of paper.

The quiz will cover all types of transport and include a few questions about cell organelles.  I would read over the organelle notes in the folder but I wouldn't dedicate a ton of time to organelles.  If you have the opportunity, studying together is a good way to check your understanding of the material.

The quiz is only 28 multiple choice questions.  We will start the next topic as soon as the quiz is done.  

Osmosis Lab write up

Draft of the Introduction and Results section due on Friday.  More detailed information will be in the Unit 2C folder, as well as sample papers.

Osmosis Lab

Jellies- make sure someone in your group emailed me a list of materials/equipment needed by 2:30 today (Monday).  If its not on the list, you won't have it for your lab!

HW is to come up with a list of procedures so that you know what to do when you come in tomorrow.

Active Transport

HW: read the rest of the same page (no really, this is the link, sorry for the bad link earlier) except for osmosis.

Here are links to the videos we watched in class today:

1. Sodium Potassium Pump
2. The nerve cell and action potential
3. Cystic Fibrosis (only first 5 min or so)

Diffusion

Finish any calculations or questions from the agar cube lab.  Turn this into your shared folder.  Next, read the Diffusion and Facilitated Diffusion sections of the following page:

http://www.uic.edu/classes/bios/bios100/lectures/diffusion.htm

You should absolutely be taking notes on these to help your understanding.  I would click on the picture (title) for each concept and label the diagram with the concepts described in the notes.

HW after quiz

Import your section's organelle notes into Notability.  Read these notes, underline and highlight as needed.  We will continue to discuss the cell and parts of the cell next class.