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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.
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http://trixyofassisi.blogspot.con/2012/01/plasma-membranes.html
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Lesson Overview Short Video Group Exploration Brief Lecture Membrane Modeling Review http://youtu.be/Qqsf_UJcfBc
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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.
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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
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Membrane Structure Phospholipids are the major structural component of membranes. Phospholipid
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Membrane Structure All membranes are phospholipid bilayers with embedded proteins. Hydrophilic heads Hydrophobic tails Phospholipid Bilayer
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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
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Membrane Proteins: integral proteins – embedded in the membrane Peripheral proteins – not embedded Examples: channels and carriers enzymes receptor proteins
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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
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Diffusion Facilitated diffusion Passive transport ATP Active transport Active Transport ChannelCarrier
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More about Active Transport
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Vesicle forming Endocytosis
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Endocytosis Cell membrane sinks inward, pinches off and forms a vesicle Brings material into the cell
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Endocytosis - terms Phagocytosis – cell eating Phagocytosis Brings in solid particles Examples: bacteria, cell debris, or food Pinocytosis – cell drinking Cell brings in a liquid
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Vesicle Fluid outside cell Protein Cytoplasm Exocytosis Movement of large molecules out of the cell.
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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
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Cholesterol Glycoprotein Glycolipid Carbohydrate of glycoprotein Phospholipid Microfilaments of cytoskeleton Protein
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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?
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Problem Why is the structure of the plasma membrane beneficial for: The Environment Functions of the cell
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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
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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
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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
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