1/9/2015• New seat• HW out for me to check in- review your key

points with your table• Quick discussion of key points• Exit slip 4.2- organelles• PPP the plasma membrane & the PM project• Time to work on presentations.• 5 minutes left in class…remind me to pass back

your test. Re-assessment is 1/14, sign up!• 4.1 back• HW: video due MONDAY at 8 PM the latest

PLASMA MEMBRANE- keeping it all together

• Isolates• Regulates• Interaction (between cells and environment)

• Made up of phospholipids

• The 2 layers of phospholipid molecules are called the phospholipid bilayer

Phosphate

Fatty acid tails

1 phospholipid

You are Watery

• The fluid that surrounds all cells in body (interstitial fluid)

• AND the cytoplasm (fluid in the cell) is:• mostly water• with• salts, proteins, lipids, carbohydrates,

sugars, amino acids, nucleotides, dissolved into it

• Ex: Think liquid in a blister or tears or sweat

Phospholipid “Sandwich”• phosphates touch

watery sides (“the bread”)

• The fatty acids (lipids) “hide” creating the inside of the PM.

phosphate

fatty acids

Plasma membrane• Called a fluid mosaic because of the different

parts AND b/c phospholipids move around.

Define: Mosaic• Mosaic is the art of creating images with an

assemblage of small pieces of colored glass, stone, or other materials

• For example Snowflake Mosaic!

•Other parts of the “mosaic” are…–Proteins do a whole host of things–Cholesterol acts as a stabilizer

Protein Functions

1. Transport

• Move molecules in or out of the cell that can’t cross the membrane

2. Signal Reception

• E.g. receives signals from hormones

• Cell can change activity or gene expression

3. Identifier

• E.g. type A or B blood

• Body can know what cell it is and not to attack it

Blood Transfusions Gone Wrong

4. Cell Connections

• Connect cell to cytoskeleton (interior side)

• Connect cell to other cells (exterior side)

PM project1. no time to build in class due to “weather days”

2. Ignore group-this is now an individual activity but follow the general directions.

3. You are NOT required to make a 3D model

4. You ARE REQUIRED to draw the PM– This can be done on a computer & printed out or by

hand.– Should be in color– If done well it will be hung up. Take pride in your

work!

5. You SHOULD define all of the parts of a cell for your learning benefit

Way Super Fancy Example of the 3D project we were going to do…

Phospholipid Head

Phospholipid Tail

Protein

Finalize your Video

• It is due Monday by 8 PM shared with me on the drive and given editing privileges. Send me an email that it is there

• This means that you also have an AcLab if you need it to finish.

• HW: drawing of PM & video