Bell Ringer (eggs up front)Observe what happened to the eggs.

Did you expect this to happen?Think about it in terms of fluid

movement.

Plasma Membrane: Structure

http://trixyofassisi.blogspot.con/2012/01/plasma-membranes.html

Lesson OverviewShort VideoGroup ExplorationBrief LectureMembrane ModelingReview

http://youtu.be/Qqsf_UJcfBc

Think, Pair, ShareRead the brochure on the plasma

membrane with the person next to you.

 Take note of several key components

of the membrane.

Discuss and decide on a favorite destination with your neighbor. We will share in a moment. 

Fluid Mosaic ModelCell Membrane is a mosaic

Proteins and other molecules are embedded in a framework

Cell Membrane is fluidMost protein and phospholipid molecules can move laterally

Membrane Structure

Phospholipids are the major structural component of membranes.

Phospholipid

Membrane StructureAll membranes are phospholipid bilayers

with embedded proteins.

Hydrophilic heads

Hydrophobic tails

Phospholipid Bilayer

Glycoproteins & Glycolipids Have short chain carbohydrates

attached on the outer side of the membrane.

Cell-cell recognition - identify type of cell and identify a cell as “self” vs. foreign

Membrane Proteins:integral proteins – embedded in the

membrane Peripheral proteins – not embeddedExamples:

channels and carriersenzymesreceptor proteins

Transport Proteins Passive Transport

Allows substances to cross the membrane by diffusionDiffusion - movement from high concentration to low concentration

no energy required

Active Transport Requires energy (ATP) to transport

substances against their concentration gradient

LE 7-17

Diffusion Facilitated diffusion

Passive transport

ATP

Active transport

Active Transport

Channel Carrier

More about Active Transport

Vesicle forming

Endocytosis

EndocytosisCell membrane sinks inward, pinches off and forms a vesicle

Brings material into the cell

Endocytosis - termsPhagocytosis – cell eating

Brings in solid particlesExamples: bacteria, cell debris, or food

Pinocytosis – cell drinkingCell brings in a liquid

Vesicle

Fluid outside cell

Protein

Cytoplasm

ExocytosisMovement of large molecules

out of the cell.

BE the Plasma MembraneUse your amazing

interpretive dance skills to BE the membrane.

The entire class will BE the membrane and model what a fellow classmate (the director) dictates. Hint: Hydrophobic arms

Fig. 5-1a

Cholesterol

Glycoprotein

Glycolipid

Carbohydrate ofglycoprotein

Phospholipid

Microfilamentsof cytoskeleton

Protein

Murky and Main PointsWrite 3 main points from today’s lesson.

Must be content-based. Ex: The plasma membrane is selectively

permeable to control what is allowed in and out of the cell.

Write 1 or more murky points from today’s lesson. This is material that is unclear to you.

Write 1 favorite point from today’s lesson. What did you enjoy about class today?

ProblemWhy is the structure of the plasma membrane beneficial for:The Environment Functions of the cell

ReviewThe plasma membrane is made of a

phospholipid _______.The phospholipids have a hydrophilic

______ and two hydrophobic _____.When ___________ is present in the

cell membrane, its presence stabilizes the membrane and hinders packing at cold temperatures.

head

bilayer

tails

cholesterol

ReviewProteins that penetrate the bilayer are

called _________ proteins. Many of these are _______________

proteins, because they completely span the membrane.

___________ proteins are not embedded in the lipid bilayer.

When carbohydrates covalently bond to proteins they are called _____________, which play a role in cell-cell recognition.

Peripheral

integral

transmembrane

glycoproteins

Review________ proteins allow hydrophilic

molecules to quickly pass from one side of the membrane to the other.

_______ proteins alternate between two conformations for molecules to be transported.

Channel

Carrier