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.

Lesson Overview Short Video Group Exploration Brief Lecture Membrane Modeling Review

Think, Pair, Share Read 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 Model Cell Membrane is a mosaic Proteins and other molecules are embedded in a framework Cell Membrane is fluid Most protein and phospholipid molecules can move laterally

Membrane Structure Phospholipids are the major structural component of membranes. Phospholipid

Membrane Structure All 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 embedded Examples: channels and carriers enzymes receptor proteins

Transport Proteins Passive Transport Allows substances to cross the membrane by diffusion Diffusion - movement from high concentration to low concentration no energy required Active Transport Requires energy (ATP) to transport substances against their concentration gradient

Diffusion Facilitated diffusion Passive transport ATP Active transport Active Transport ChannelCarrier

More about Active Transport

Vesicle forming Endocytosis

Endocytosis Cell membrane sinks inward, pinches off and forms a vesicle Brings material into the cell

Endocytosis - terms Phagocytosis – cell eating Phagocytosis Brings in solid particles Examples: bacteria, cell debris, or food Pinocytosis – cell drinking Cell brings in a liquid

Vesicle Fluid outside cell Protein Cytoplasm Exocytosis Movement of large molecules out of the cell.

BE the Plasma Membrane Use 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

Cholesterol Glycoprotein Glycolipid Carbohydrate of glycoprotein Phospholipid Microfilaments of cytoskeleton Protein

Murky and Main Points Write 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?

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

Review The 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

Review Proteins 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