Active Transport Intro and endocytosis demonstration

Tuesday November 27th 

If you go to the hospital for dehydration they will administer IV saline solution to you.  This contains about 1-2% dissolved substances and 98-99% water. 

When you FIRST go in with a low concentration of water in your cells what direction will water flow (into or out of your cells).
INTO your cells.  What type of solution would this be at this point? Hypotonic

Eventually you will be rehydrated and the saline solution is now the same concentration as that of your cells.  What direction will water flow now? It will move into and out of our cells at an equal rate (any excess will be removed as urine then)  What type of solution would this be considered? Because it is the same concentration as your own cells it would be considered an isotonic solution.

Those daily questions wrapped up our discussion on osmosis and we started into the notes on active transport.  This is the last section of this chapter and I plan on having a test on Friday.  Check edline for the notes.  Below is a demonstration I did on how endocytosis works.
 

Here we have a cell - the clay represents the cell membrane

Some molecules are too large to move through the phospholipids
or transport proteins but SOMEHOW find a way to make it
into and out of the cell

First the cell membrane starts to fold around the molecule

It continues to "engulf" the molecule and begins pinching off

Eventually the molecule will be released inside the cell
and the cell membrane will never have "opened up"

If we could take a look at the inside of the cell we would see
that molecule is now found in a vesicle which is made up
of part of the cell membrane

A look inside the vesicle