Download Do Now (Cell membrane Day 1)

Opening Activity 11/3/15
Scientists refer to the cell membrane
as a fluid mosaic model. What is a
mosaic? (hint: the pictures below are
mosaics)
Parts of the cell membrane
Essential question: What are the
components of a cell membrane, and
how do they work?
Overview
• Cell membrane separates living cell from nonliving
surroundings
• Controls traffic in & out of the cell
– selectively permeable
– allows some substances to cross more easily than
others
Phospholipid
• Phosphate group head
– Contains a phosphate
– Hydrophilic – loves the water
• Fatty acid tails
– Contain carbon and hydrogen
– Hydrophobic – water fearing
Phospholipid bilayer
• There is water inside and
outside the cell
• Phospholipids arrange
themselves with
hydrophobic tails on the
inside and hydrophilic
heads on the outside.
• Together it is the
phospholipid bilayer (bi =
two)
• This is the basic structure
of the cell membrane
Proteins: channel or transport
• Go all the way through the
phospholipid bilayer, and
have tunnel in the middle
• Allow molecules to pass
through the tunnel part
• May or may not require
energy. May or may not
change shape as the
molecule goes through.
Many Functions of Membrane Proteins
Outside
Plasma
membrane
Inside
AP Biology
Transporter
Enzyme
activity
Cell surface
receptor
Cell surface
identity marker
Cell adhesion
Attachment to the
cytoskeleton
The cell membrane . . . ta da!
This is just a
tiny slice
through the
cell
membrane –
remember it
covers the
whole cell,
and it all
looks like this
if you cut out
a piece of it
Cells Video
• http://www.youtube.com/watch?v=dPKvHrD1
eS4
9
Finish Build-A-Membrane
• Make sure your name is on your model and
put it in the bin at the front of the room
• Put the worksheet in the In-Box at the back
of the room
• Clean up & put away all supplies
10
Closing Activity/Exit Ticket
You will turn this in!
Give Me 5!
•On a ½ sheet of paper with your name, date,
and period, write down 5 words that come to
mind when you think about the structure of the
cell membrane (individual words, not a
sentence)