Monday 1/9/12Monday 1/9/12

AIM:AIM: How is the structure of the plasma How is the structure of the plasma membrane related to its function?membrane related to its function?

DO NOW:DO NOW: In complete sentences, explain In complete sentences, explain why every cell has a cell membrane.why every cell has a cell membrane.

Homework:Homework: Take home cell questions 1- Take home cell questions 1-2020

DO NOW ANSWERDO NOW ANSWER

The cell membrane regulates what enters The cell membrane regulates what enters and leaves the celland leaves the cell

Construction of the Cell MembraConstruction of the Cell Membranene

Wisconsin Online Wisconsin Online

How is the cell membrane How is the cell membrane constructed?constructed?

The cell membraneThe cell membrane

Plasma membranePlasma membrane

Phospholipid bilayerPhospholipid bilayer

2 layers of 2 layers of phospholipidsphospholipids

Embedded with Embedded with proteins and proteins and cholesterol moleculecholesterol molecule

Functions of the cell membraneFunctions of the cell membrane

Helps to maintain balance or homeostasis Helps to maintain balance or homeostasis within the cellwithin the cell

Boundary between cell and its Boundary between cell and its environmentenvironment

Selectively permeable: allows some to Selectively permeable: allows some to pass and others are kept outpass and others are kept out

PhospholipidPhospholipid

Hydrophillic heads

Hydrophobic tails

Fluid Mosaic modelFluid Mosaic modelIndividual phospholipids Individual phospholipids are not bondedare not bondedFluid because Fluid because phospholipids move phospholipids move within the membranewithin the membraneAt the same time, At the same time, proteins in the proteins in the membrane also move membrane also move among the among the phospholipidsphospholipidsThese proteins create a These proteins create a mosaic modelmosaic model

Why is it important for the Why is it important for the membrane to be partly membrane to be partly hydrophobic and partly hydrophobic and partly

hydrophillic?hydrophillic?

Tuesday 1/10/12Tuesday 1/10/12

AIM:AIM: How is the cell membrane a fluid How is the cell membrane a fluid mocaic?mocaic?

DO NOW:DO NOW: 1- List the other two names for 1- List the other two names for the cell membranethe cell membrane

2- Explain the difference between 2- Explain the difference between hydrophillic and hydrophobichydrophillic and hydrophobic

HOMEWORK:HOMEWORK: Take home test 21-40. ALL Take home test 21-40. ALL OF IT MUST BE DONE BY TOMORROW!OF IT MUST BE DONE BY TOMORROW!

Water soluble at the outer surfaces and Water soluble at the outer surfaces and insoluble at inner surfaces. H bonds form insoluble at inner surfaces. H bonds form

between water and hydrophillic headsbetween water and hydrophillic heads

Why does the membrane need Why does the membrane need cholesterol?cholesterol?

Helps stabilize the membraneHelps stabilize the membrane

Help the hydrophobic tails moveHelp the hydrophobic tails move

What is the difference between an What is the difference between an integral and peripheral protein?integral and peripheral protein?

Peripheral proteins: only sit on Peripheral proteins: only sit on the surface of the membranethe surface of the membrane

Integral protein: extend Integral protein: extend through both layers of through both layers of phospholipid bilayerphospholipid bilayer

Membrane proteinsMembrane proteins

Fibrous proteins: receptorsFibrous proteins: receptors

Glycoproteins: cell to cell recognition or Glycoproteins: cell to cell recognition or identificationidentification

Pore proteins: passive transportPore proteins: passive transport

Channel proteins: active transportChannel proteins: active transport

Glyco proteinGlyco protein

Glyco: tells me that it Glyco: tells me that it is part carbohydrateis part carbohydrate

Protein: part proteinProtein: part protein

How does the structure of the How does the structure of the membrane relate to its function?membrane relate to its function?

1- hydrophobic tails create a barrier 1- hydrophobic tails create a barrier between inside and outside of the cellbetween inside and outside of the cell2- hydrophillic heads allow small water 2- hydrophillic heads allow small water soluble molecules to bond to the membranesoluble molecules to bond to the membrane3- cholesterol creates small gaps for the 3- cholesterol creates small gaps for the molecules to “sneak” across the membranemolecules to “sneak” across the membrane4- Membrane proteins help molecules move 4- Membrane proteins help molecules move in and out of the cellin and out of the cell5- Glycoproteins allow the cell to rcognize 5- Glycoproteins allow the cell to rcognize and be recognized by other cellsand be recognized by other cells

Why is the plasma membrane Why is the plasma membrane selectively permeable?selectively permeable?

Wednesday 1/11/12Wednesday 1/11/12

AIM:AIM: How does the plasma membrane How does the plasma membrane regulate movement of molecules into and regulate movement of molecules into and out of the cell?out of the cell?DO NOW:DO NOW: In complete sentences explain In complete sentences explain what you would do in the following what you would do in the following situation: You are at a dance that contains situation: You are at a dance that contains 100 kids within 1 hour the dance fills up 100 kids within 1 hour the dance fills up with 800 kids and you can hardly move. with 800 kids and you can hardly move. What would you do and why?What would you do and why?

Construction of the Cell MembraConstruction of the Cell Membranene

Wisconsin Online Wisconsin Online

How do molecules move across How do molecules move across the plasma membrane?the plasma membrane?

Lipid soluble molecules cross the Lipid soluble molecules cross the membrane with no helpmembrane with no help

Other molecules use membrane Other molecules use membrane proteinsproteins

TransportTransport

Passive: molecules move from a high to Passive: molecules move from a high to low concentrationlow concentration

Active: molecules move from low to high Active: molecules move from low to high concentrationconcentration

Thursday 1/12/12Thursday 1/12/12

AIM:AIM: How do molecules move across the How do molecules move across the cell membrane?cell membrane?

DO NOW:DO NOW: List the parts of the cell List the parts of the cell membranemembrane

Homework:Homework: 1- Work on topic 2 of the 1- Work on topic 2 of the midterm reviewmidterm review

How does the concentration How does the concentration gradient determine if molecules gradient determine if molecules

will cross the cell membrane will cross the cell membrane passively or actively?passively or actively?

Transport across the membraneTransport across the membrane

cytoplasm has different cytoplasm has different molecules and ions. molecules and ions.

Some easily pass through Some easily pass through the plasma membrane the plasma membrane into the cell. into the cell.

These include water, These include water, oxygen and glucose oxygen and glucose molecules, and sodium molecules, and sodium and chloride ions.and chloride ions.

Passive TransportPassive Transport

Small lipid soluble molecules move from a Small lipid soluble molecules move from a crowded area to a less crowded areacrowded area to a less crowded areaDown the concentration gradientDown the concentration gradient– High concentration (lots of molecules) to low High concentration (lots of molecules) to low

concentration (less molecules)concentration (less molecules)

No energy is requiredNo energy is requiredSize and solubility of molecules determine Size and solubility of molecules determine its ability to cross the membraneits ability to cross the membraneSolubility= what a molecule can dissolve inSolubility= what a molecule can dissolve in

Passive transportPassive transport

Passive transportPassive transport

Simple diffusionSimple diffusion

OsmosisOsmosis

Facilitated diffusionFacilitated diffusion

DiffusionDiffusion

Movement is driven Movement is driven by by concentration concentration gradientgradient

Molecules move from Molecules move from an area of an area of high high concentration to concentration to lowlow concentrationconcentration

Solute concentration Solute concentration is equalis equal

http://www.indiana.edu/~phys21http://www.indiana.edu/~phys215/lecture/lecnotes/lecgraphics/di5/lecture/lecnotes/lecgraphics/diffusion2.gifffusion2.gif

http://highered.mcgraw-hill.com/sithttp://highered.mcgraw-hill.com/sites/0072495855/student_view0/ches/0072495855/student_view0/chapter2/animation__how_diffusion_apter2/animation__how_diffusion_works.htmlworks.html

Facilitated diffusionFacilitated diffusion

Some molecules are Some molecules are too big to passively too big to passively diffuse diffuse

So they need the help So they need the help of carrier proteinsof carrier proteins

Transport is still Transport is still driven by a driven by a concentration concentration gradientgradient

What are the different types What are the different types of transport?of transport?

Passive and activePassive and active

How are passive and active How are passive and active transport different?transport different?

Passive: driven by Passive: driven by concentration gradientconcentration gradient

Active: driven by ATPActive: driven by ATP

OsmosisOsmosis

Simple diffusion of Simple diffusion of waterwater

From an area of From an area of higher higher concentrationconcentration to a to a region where they are region where they are in a in a lower lower concentrationconcentration

Isotonic: equal movement of water Isotonic: equal movement of water into and out of cellinto and out of cell

Hypotonic solution: net water Hypotonic solution: net water movement into the cellmovement into the cell

Hypertonic: net movement of water Hypertonic: net movement of water out of the cellout of the cell

Aim:Aim: Why does the cell use energy to move Why does the cell use energy to move molecules across the cell membrane?molecules across the cell membrane?

Do Now:Do Now: Use your table from yesterday or Use your table from yesterday or create a new table organizing the osmotic create a new table organizing the osmotic environments and the flow of water in each. In a environments and the flow of water in each. In a third column of your table, draw a picture of each third column of your table, draw a picture of each using an x to represent solute molecules and o using an x to represent solute molecules and o to represent water molecules. to represent water molecules.

How does the concentration How does the concentration gradient determine the gradient determine the direction of molecule direction of molecule

movement across the cell movement across the cell membrane?membrane?

Active transportActive transport

Movement of substances Movement of substances againstagainst a a concentration gradientconcentration gradient

From From low to highlow to high

Needs energyNeeds energy

Membrane proteins use energy to move Membrane proteins use energy to move individual moleculesindividual molecules

How does active transport differ How does active transport differ from facilitated diffusion?from facilitated diffusion?

AIM: How does the cell use energy to AIM: How does the cell use energy to transport molecules across the plasma transport molecules across the plasma membrane?membrane?

DO NOW: Use the picture displayed to DO NOW: Use the picture displayed to explain the process:explain the process:

How is active transport different How is active transport different from passive transport?from passive transport?

Passive transport does Passive transport does not need energy to move not need energy to move molecules from high to molecules from high to low concentrationlow concentration

Active Transport uses Active Transport uses energy to move energy to move molecules against the molecules against the concentration gradientconcentration gradient

Why is active transport necessary Why is active transport necessary for homeostasis?for homeostasis?

Certain molecules need to enter or leave Certain molecules need to enter or leave the cell against their concentration the cell against their concentration gradientgradient

Active transportActive transport

Endocytosis: cell uses energy to carry Endocytosis: cell uses energy to carry molecules insidemolecules inside

Exocytosis: remove contents from the cellExocytosis: remove contents from the cell

Ion pumps Ion pumps

Co-transportCo-transport

Active transportActive transport

Endocytosis: intake of Endocytosis: intake of particles or fluids in to particles or fluids in to the cellthe cell

Pinocytosis: cell Pinocytosis: cell drinkingdrinking

Phagocytosis: cell Phagocytosis: cell eatingeating

Phagocytosis in an amebaPhagocytosis in an ameba

Ion TransportIon Transport

CotransportCotransport

movement of 2 movement of 2 solutes togethersolutes together

often moves 1 solute often moves 1 solute passively & other passively & other actively actively

AssessmentAssessment

In your notebooks draw the picture In your notebooks draw the picture depicted below and explain how molecules depicted below and explain how molecules move in the direction of the arrowsmove in the direction of the arrows