Topic 1 Cell Biology. 1.4 Membrane Transport. Essen:al Ques:on: Membranes control the composi1on of cells by ac1ve and passive transport

Size: px
Start display at page:

Download "Topic 1 Cell Biology. 1.4 Membrane Transport. Essen:al Ques:on: Membranes control the composi1on of cells by ac1ve and passive transport"

Transcription

1 Topic 1 Cell Biology 1.4 Membrane Transport Essen:al Ques:on: Membranes control the composi1on of cells by ac1ve and passive transport

2 Phospholipid bilayer is selec:vely permeable controlled entry/exit of molecules What controls how substances Move thru the membrane? Size of the molecule (selec:ve permeability) Charge of the molecule What moves easily thru the membrane? (diffusion) Water Carbon dioxide Oxygen What does NOT move easily thru the membrane? (facilitated diffusion &/or ac5ve transport) Large molecules such as glucose and proteins molecules or atoms with charges, such as ions (sodium, potassium, calcium)

3 Embedded Proteins Channel Proteins Form small openings for molecules to diffuse through Carrier Proteins Binding site on protein surface selects certain molecules and allows them to pass through Receptor Proteins Molecular triggers that set off cell responses (release of hormones) Cell Recogni:on Proteins ID tags to iden:fy certain cells to the body s immune system Enzyma:c Proteins Carry out metabolic reac:ons

4

5

6 Solu5ons consist of solutes dissolved in a solvent Concentration is a measure of the amount of solute in the solution Modified/adapted from i-biology.net

7 Passive Transport Does NOT require chemical energy from the cell Depends on permeability of the cell Consider characteristics of the membrane (lipids, proteins, etc) Three main types: 1. Diffusion 2. Facilitated transport 3. Osmosis

8 1. Simple Diffusion Movement of molecules from an area of HIGH concentra:on (more solute) to LOW concentra:on (less solute) These molecules follow their concentra:on gradient Cells are able to dispose of O 2, CO 2, and H 2 O without energy

9 n chapter2/animation how_diffusion_works.html

10 Name three factors, other than temperature, that affect the rate of diffusion of a solute across a membrane. Concentra:on Gradient Surface Area Length of Diffusion Path

11 Several factors determine rate of diffusion: Number of molecules in cell (mol) Permeability of a particular molecule Surface area (SA) Width of cell membrane Concentration of diffusing molecule (mole/cm 3 ) Temperature (rate s as temp s) Maximize SA for Absorption: alveoli in lungs (grapelike sacs) membrane folds in mitochondria and in cristae of chloroplasts root hairs for water and mineral uptake villi for absorption of digested food in S. Intestine Reduce length of diffusion path: Folded membranes increase SA:VOL ratio more membrane in smaller volume = shorter distance across for molecules to diffuse membranes are very thin (7-10nm)

12 2. Facilitated Diffusion/Transport Movement of a molecule from an area of [HIGH] to [lower] with the aid of proteins (carrier or channel proteins) Channels /Carriers work as a facilita:ng pathways for larger molecules or charged ions (amino acids, glucose, Na + and K+) Highly specific proteins for each molecule

13 Facilitated Transport - McGraw-Hill

14 3. Osmosis Diffusion of WATER through a semi-permeable membrane Water moves from high H 2 O potential and low [solute] to low H 2 O potential and hi [solute]

15 Given: Question: A - 100% water B - 90% water What direction does the water flow?

16 Given: Question: A - 100% water B - 90% water What direction does the water flow? Water flows from A --> B

17 Given: Question: A - 1% glucose B - 20% glucose What direction does the water flow? What direction does the glucose flow?

18 Given: Question: A - 1% glucose B - 20% glucose What direction does the water flow? Water flows from A --> B What direction does the glucose flow? Glucose flows from B --> A

19 Compare diffusion and osmosis.

20 Compare diffusion and osmosis.

21 Types of Solutions: 1. Hypertonic Hyper = more ; tonic = solute Thus, a cell in a solute rich environment Water flows outward from region of high [water] to low [water] (or low to high [solute]) Cell undergoes plasmolysis (fluid loss) and crenate (shrivel)

22 2. Hypotonic Hypo = less ; tonic = solute Thus, a cell in a solute poor environment Water flows inward from region of high [water] to low [water] Cell undergoes cytolysis (cell breaks) and bursts

23 3. Isotonic Iso = equal ; tonic = solute Thus, a [solute] both equal within and outside the cell Water flows in and out of cell with net zero movement Equilibrium

24 n student_view0/chapter2/ animation how_osmosis_works.html

25 Ac5ve Transport Requires chemical energy (ATP) Involves movement of molecules against a concentra:on gradient using membrane protein pumps

26

27 Endocytosis and Exocytosis Enter cell process exit cell process Exocytosis export of macromolecules from the cell Endocytosis the import of macromolecules ENDOCYTOSIS (endo=inside; cyte=cell) Phagocytosis the ingestion of solid molecules Pinocytosis the ingestion of liquids and solutes

28 Endocytosis: Phagocytosis Ingest large particles Endocytosis: Pinocytosis engulf very small particles or liquids sipping

29 EXOCYTOSIS (exo=outside; cyte=cell) Export of a secretory vesicle that will migrate to membrane s inner surface and fuse with membrane Contents are forced out of the cell Opposite of endocytosis Examples: peptide hormones, steroid hormones, wastes

30 1. Protein is synthesised and present in the rer. Then protein is moved through the rer and modified. 2. A spherical vesicle is formed form the end of the rer with the protein inside. 3. The vesicle migrates to the Golgi and the membranes fuse. The protein is released into lumen of the Golgi. 4. Golgi modifies the protein further by adding lipid or polysaccharides 5. A new vesicle is formed from Golgi membrane which then breaks away. 6. The vesicle migrates to the plasma membrane fuses and secretes content its contents out of the cell. A process called exocytosis

31

32 How Do Membranes Fuse? 1. Vesicle approaches the plasma membrane. All membranes are made up of phospholipids so they share the same proper:es 2. The membrane begins to fuse. Remember the fluidity of the plasma membrane phospholipids can flow around each other 3. For a moment, there is a single phospholipid bilayer at the point of contact = temporary intermediate structure 4. The membrane pore opens, allowing its contents to pass through. No:ce that there is never an unbroken sec:on of the membrane through the en:re process.

33 Exocytosis - vesicle membrane fuses with the plasma membrane. Endocytosis - vesicle formed by the infolding of the plasma membrane In each of the cases above the membranes are able to form and break without loss of the con1nuity of the plasma membranes. The phospholipid molecules are constantly changing places in the horizontal plane crea:ng the fluid property of the membrane. Exchange in the ver:cal plane does not occur. This maintains the integrity of the membrane.

Cell Biology. The Plasma Membrane

Cell Biology. The Plasma Membrane Cell Biology The Plasma Membrane recall Fluid Mosiac Model S.J. Singer Semipermeable membrane fluid portion is double layer of phospholipids (=phospholipid bilayer) mosaic portion is the proteins and carbohydrates

More information

Plasma Membrane Structure and Function

Plasma Membrane Structure and Function Plasma Membrane Structure and Function The plasma membrane separates the internal environment of the cell from its surroundings. The plasma membrane is a phospholipid bilayer with embedded proteins. The

More information

CH 7.2 & 7.4 Biology

CH 7.2 & 7.4 Biology CH 7.2 & 7.4 Biology LABEL THE MEMBRANE Phospholipids Cholesterol Peripheral proteins Integral proteins Cytoskeleton Cytoplasm Extracellular fluid Most of the membrane A phospholipid bi-layer makes up

More information

Homeostasis, Transport & The Cell Membrane. Chapter 4-2 (pg 73 75) Chapter 5

Homeostasis, Transport & The Cell Membrane. Chapter 4-2 (pg 73 75) Chapter 5 Homeostasis, Transport & The Cell Membrane Chapter 4-2 (pg 73 75) Chapter 5 Unit 5: Lecture 1 Topic: The Cell Membrane Covers: Chapter 5, pages 95-96 Chapter 4, pages 73-75 The Cell Membrane The chemistry

More information

Cell Structure and Function Practice Exam - KEY

Cell Structure and Function Practice Exam - KEY Biology 12 Name: Cell Structure and Function Practice Exam - KEY Cell parts and Function 1. Identify each part of the cell indicated and give one role for each structure in the secretion and/or synthesis

More information

Gateway to the Cell 11/1/2012. The cell membrane is flexible and allows a unicellular organism to move FLUID MOSAIC MODEL

Gateway to the Cell 11/1/2012. The cell membrane is flexible and allows a unicellular organism to move FLUID MOSAIC MODEL Gateway to the Cell The cell membrane is flexible and allows a unicellular organism to move Isolates the cell, yet allows communication with its surroundings fluid mosaics = proteins (and everything else)

More information

Movement of Substances in the Cell

Movement of Substances in the Cell Movement of Substances in the Cell The Marble Memories Biology All cells are surrounded by a plasma membrane (also called cell membrane). This membrane regulates the entry and exit of substances into and

More information

Transport. Slide 1 of 47. Copyright Pearson Prentice Hall

Transport. Slide 1 of 47. Copyright Pearson Prentice Hall & Transport 1 of 47 Learning Targets TN Standard CLE 3216.1.3 Explain how materials move into and out of cells. CLE 3216.1.5 Investigate how proteins regulate the internal environment of a cell through

More information

Cellular Transport. Biology Honors

Cellular Transport. Biology Honors Cellular Transport Biology Honors Review of Concepts and Introduction to the Current Concepts https://www.youtube.com/watch?v=ptmlvtei 8hw Passive Active No energy Requires / needs energy Passive Transport-

More information

Ch3: Cellular Transport Review KEY

Ch3: Cellular Transport Review KEY Ch3: Cellular Transport Review KEY OSMOSIS Label the pictures below ( isotonic, hypertonic, or hypotonic environments) hypotonic hypertonic isotonic hypertonic means there is a GREATER concentration of

More information

CELL BOUNDARIES. Cells create boundaries through: Cell Membranes made of the phospholipid bilayer Cell Walls made of cellulose in plants

CELL BOUNDARIES. Cells create boundaries through: Cell Membranes made of the phospholipid bilayer Cell Walls made of cellulose in plants CELL BOUNDARIES CELL BOUNDARIES Cells create boundaries through: Cell Membranes made of the phospholipid bilayer Cell Walls made of cellulose in plants TYPES OF MEMBRANES Some substances = too large or

More information

TRANSPORT ACROSS MEMBRANES

TRANSPORT ACROSS MEMBRANES Unit 2: Cells, Membranes and Signaling TRANSPORT ACROSS MEMBRANES Chapter 5 Hillis Textbook TYPES OF TRANSPORT ACROSS THE CELL (PLASMA) MEMBRANE: What do you remember? Complete the chart with what you

More information

Maintained by plasma membrane controlling what enters & leaves the cell

Maintained by plasma membrane controlling what enters & leaves the cell CELL TRANSPORT AND HOMEOSTASIS Homeostasis Balanced internal condition of cells Also called equilibrium Maintained by plasma membrane controlling what enters & leaves the cell Functions of Plasma Membrane

More information

Cellular Transport Notes

Cellular Transport Notes Cellular Transport Notes About Cell Membranes All cells have a cell membrane Functions: a. Controls what enters and exits the cell to maintain an internal balance called homeostasis b. Provides protection

More information

The Plasma Membrane - Gateway to the Cell

The Plasma Membrane - Gateway to the Cell The Plasma Membrane - Gateway to the Cell 1 Photograph of a Cell Membrane 2 Cell Membrane The cell membrane is flexible and allows a unicellular organism to move 3 Homeostasis Balanced internal condition

More information

Equilibrium when two areas have the same concentration or are filled evenly

Equilibrium when two areas have the same concentration or are filled evenly Aim: How does the cell membrane function to maintain homeostasis? Do Now: Describe what homeostasis is. Homework: Vocab: Homeostasis, equilibrium, concentration gradient, diffusion, carrier protein, osmosis,

More information

CELL TRANSPORT and THE PLASMA MEMBRANE. SB1d. Explain the impact of water on life processes (i.e., osmosis, diffusion).

CELL TRANSPORT and THE PLASMA MEMBRANE. SB1d. Explain the impact of water on life processes (i.e., osmosis, diffusion). CELL TRANSPORT and THE PLASMA MEMBRANE SB1d. Explain the impact of water on life processes (i.e., osmosis, diffusion). What if What would happen if an organism could not get energy or get rid of wastes?

More information

Draw and label a diagram to show the structure of membranes

Draw and label a diagram to show the structure of membranes 2.4 Membranes 2.4.1 - Draw and label a diagram to show the structure of membranes Phospholipid Bilayer - This is arranged with the hydrophilic phosphate heads facing outwards, and the hydrophobic fatty

More information

Transport: Cell Membrane Structure and Function. Biology 12 Chapter 4

Transport: Cell Membrane Structure and Function. Biology 12 Chapter 4 Transport: Cell Membrane Structure and Function Biology 12 Chapter 4 FLUID-MOSAIC MODEL OF MEMBRANE STRUCTURE The cell membrane (plasma membrane) is made of two layers of phospholipid molecules (bilayer)

More information

Diffusion, Osmosis and Active Transport

Diffusion, Osmosis and Active Transport Diffusion, Osmosis and Active Transport Particles like atoms, molecules and ions are always moving Movement increases with temperature (affects phases of matter - solid, liquid, gas) Solids - atoms, molecules

More information

Ch. 5 Homeostasis & Cell Transport

Ch. 5 Homeostasis & Cell Transport Ch. 5 Homeostasis & Cell Transport 5.1 Homeostasis & Permeability Homeostasis ability of cell to maintain balance needed for life To maintain balance: cells must transport needed materials into cells &

More information

Chapter 3 Review Assignment

Chapter 3 Review Assignment Class: Date: Chapter 3 Review Assignment Multiple Choice 40 MC = 40 Marks Identify the choice that best completes the statement or answers the question. 1. Which of the following organelles produces transport

More information

The Plasma Membrane - Gateway to the Cell

The Plasma Membrane - Gateway to the Cell The Plasma Membrane - Gateway to the Cell 1 Photograph of a Cell Membrane 2 Cell Membrane The cell membrane is flexible and allows a unicellular organism to move 3 Homeostasis Balanced internal condition

More information

Chapter 4 Skeleton Notes: Membrane Structure & Function

Chapter 4 Skeleton Notes: Membrane Structure & Function Chapter 4 Skeleton Notes: Membrane Structure & Function Overview/Objectives 4.1 Plasma Membrane Structure & Function o Structure and Function of the PM o Major functions of proteins 4.2- Permeability of

More information

Chapter 4. Membrane Structure and Function. Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Chapter 4. Membrane Structure and Function. Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 4 Membrane Structure and Function Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1 4.1 Plasma Membrane Structure and Function Regulates the entrance

More information

Chapter 7-3 Cell Boundaries

Chapter 7-3 Cell Boundaries Chapter 7-3 Cell Boundaries The Plasma Membrane: Cell Membrane Regulates what enters and leaves the cell. Provides protection and support. Highly selective barrier!!!! What the plasma membrane is made

More information

The Transport of Materials Across Cell Membranes

The Transport of Materials Across Cell Membranes The Transport of Materials Across Cell Membranes EK 2.B.1.b. LO 2.10 The Plasma Membrane 2 EK 2.B.1.b. LO 2.10 The Plasma Membrane The cell membrane is said to be semi permeable or selectively permeable

More information

Review: Cellular Transport

Review: Cellular Transport Review: Cellular Transport OSMOSIS 1. Label the pictures below ( isotonic, hypertonic, or hypotonic). The dots represent solutes. A. B. C. 2. means there is a GREATER concentration of solute molecules

More information

Cell Boundaries Section 7-3

Cell Boundaries Section 7-3 Cell Boundaries Section 7-3 The most important parts of a cell are its borders, which separate the cell from its surroundings. The cell membrane is a thin, flexible barrier that surrounds all cells. The

More information

Slide 2 of 47. Copyright Pearson Prentice Hall. End Show

Slide 2 of 47. Copyright Pearson Prentice Hall. End Show 2 of 47 7-3 Cell Boundaries All cells are surrounded by a thin, flexible barrier known as the cell membrane. Many cells also produce a strong supporting layer around the membrane known as a cell wall.

More information

Cellular Transport Notes

Cellular Transport Notes Cellular Transport Notes About Cell Membranes 1.All cells have a cell membrane a.controls what enters and exits the cell to maintain an internal balance called homeostasis b.provides protection and support

More information

Peroxisomes. Endomembrane System. Vacuoles 9/25/15

Peroxisomes. Endomembrane System. Vacuoles 9/25/15 Contains enzymes in a membranous sac that produce H 2 O 2 Help survive environmental toxins including alcohol Help the cell use oxygen to break down fatty acids Peroxisomes Endo System Components of the

More information

Plasma Membrane & Movement of Materials in Cells

Plasma Membrane & Movement of Materials in Cells Plasma Membrane & Movement of Materials in Cells Why do cells need to control what enters and exits? Plasma membrane boundary between the cell and its environment Homeostasis maintaining the cells environment

More information

MEMBRANE STRUCTURE & FUNCTION

MEMBRANE STRUCTURE & FUNCTION MEMBRANE STRUCTURE & FUNCTION Chapter 8 KEY CONCEPTS Cellular s are fluid mosaics of lipids and proteins Membrane structure results in selective permeability Passive transport is diffusion of a substance

More information

The Cell Membrane. Also known as the Plasma Membrane

The Cell Membrane. Also known as the Plasma Membrane Student Objectives Know the different parts of the cell membrane Understand the role of the cell membrane in cellular transport Understand diffusion and osmosis Determine what will happen to plant and

More information

Plasma Membrane Function

Plasma Membrane Function Plasma Membrane Function Cells have to maintain homeostasis, they do this by controlling what moves across their membranes Structure Double Layer of phospholipids Head (polar) hydrophiliclikes water -

More information

Unit 1 Matter & Energy for Life

Unit 1 Matter & Energy for Life Unit 1 Matter & Energy for Life Chapter 2 Interaction of Cell Structure Biology 2201 Sept. 2011 Primary Membrane Function: Homeostasis Section 2.2 Conditions in the cell must remain more or less constant

More information

Transport Across a Membrane SEPT. 22, 2017

Transport Across a Membrane SEPT. 22, 2017 Transport Across a Membrane SEPT. 22, 2017 Function (1) Passive Transport (2) Active Transport (3) Endocytosis/Exocytosis TOPICS Function Function Maintains internal cell environment at a steady state,

More information

Plasma Membranes. Plasma Membranes WJEC GCE BIOLOGY 4.6

Plasma Membranes. Plasma Membranes WJEC GCE BIOLOGY 4.6 4.6 Repeat Fig 3.20A here Fluid Mosaic Model of the Plasma Membrane Carbohydrate chain Glycoprotein Intrinsic Protein Non-polar hydrophobic fatty acid Phospholipids Appearance of the Cell Membrane Seen

More information

Cell Membranes and Signaling

Cell Membranes and Signaling 5 Cell Membranes and Signaling Concept 5.1 Biological Membranes Have a Common Structure and Are Fluid A membrane s structure and functions are determined by its constituents: lipids, proteins, and carbohydrates.

More information

Chapter 4: Cell Membrane Structure and Function

Chapter 4: Cell Membrane Structure and Function Chapter 4: Cell Membrane Structure and Function Plasma Membrane: Thin barrier separating inside of cell (cytoplasm) from outside environment Function: 1) Isolate cell s contents from outside environment

More information

Cell Membrane (Transport) Notes

Cell Membrane (Transport) Notes Cell Membrane (Transport) Notes Cell Membrane and Cell Wall: ALL cells have a cell membrane made of proteins and lipids protein channel Cell Membrane Layer 1 Layer 2 lipid bilayer protein pump SOME cells

More information

Unit 1 Matter & Energy for Life

Unit 1 Matter & Energy for Life Unit 1 Matter & Energy for Life Chapter 2 Interaction of Cell Structures Biology 2201 Primary Membrane Function: Homeostasis Section 2.2 Conditions in the cell must remain more or less constant under many

More information

Cells and Their Environment Chapter 8. Cell Membrane Section 1

Cells and Their Environment Chapter 8. Cell Membrane Section 1 Cells and Their Environment Chapter 8 Cell Membrane Section 1 Homeostasis Key Idea: One way that a cell maintains homeostasis is by controlling the movement of substances across the cell membrane. Homeostasis

More information

CELL MEMBRANE & CELL TRANSPORT

CELL MEMBRANE & CELL TRANSPORT CELL MEMBRANE & CELL TRANSPORT Homeostasis: Maintaining a Balance Organisms must adjust to changes in their environment. If not DEATH! A formal definition is maintaining a stable internal condition despite

More information

Chapter 8 Cells and Their Environment

Chapter 8 Cells and Their Environment Chapter Outline Chapter 8 Cells and Their Environment Section 1: Cell Membrane KEY IDEAS > How does the cell membrane help a cell maintain homeostasis? > How does the cell membrane restrict the exchange

More information

Unit 1 Matter & Energy for Life

Unit 1 Matter & Energy for Life Unit 1 Matter & Energy for Life Chapter 2 Interaction of Cell Structure Biology 2201 Primary Membrane Function: Homeostasis Conditions in the cell must remain more or less constant under many different

More information

Cell Membrane and Transport Cell Membrane and Cell Wall: ALL cells have a cell membrane made of proteins and lipids

Cell Membrane and Transport Cell Membrane and Cell Wall: ALL cells have a cell membrane made of proteins and lipids Cell Membrane and Transport Cell Membrane and Cell Wall: ALL cells have a cell membrane made of proteins and lipids protein channel Cell Membrane Layer 1 Layer 2 lipid bilayer protein pump SOME cells have

More information

Controlled via the Cell Membrane

Controlled via the Cell Membrane CELL TRANSPORT 1 Controlled via the Cell Membrane Passive Transport Does NOT require energy, moves from HIGH concentrations to LOW concentrations Active Transport DOES require energy, moves from LOW concentrations

More information

Membrane Structure. Membrane Structure. Membranes. Chapter 5

Membrane Structure. Membrane Structure. Membranes. Chapter 5 Membranes Chapter 5 Membrane Structure The fluid mosaic model of membrane structure contends that membranes consist of: -phospholipids arranged in a bilayer -globular proteins inserted in the lipid bilayer

More information

Example - Paramecium contain contractile vacuoles that collect and remove excess water, thereby helping to achieve homeostasis

Example - Paramecium contain contractile vacuoles that collect and remove excess water, thereby helping to achieve homeostasis Homeostasis Process by which organisms maintain a relatively stable internal environment; All organisms have ranges that are tolerated (i.e. ph and temperature) Example - Paramecium contain contractile

More information

9/20/2016 CHAPTER 7 LECTURE NOTES. Section Objectives. Explain how a cell s plasma membrane functions.

9/20/2016 CHAPTER 7 LECTURE NOTES. Section Objectives. Explain how a cell s plasma membrane functions. CHAPTER 7 LECTURE NOTES Kennedy biol. 1ab Section Objectives Explain how a cell s plasma membrane functions. Relate the function of the plasma membrane to the fluid mosaic model. All living cells must

More information

Equilibrium is a condition of balance. Changes in temperature, pressure or concentration can cause a shift in the equilibrium.

Equilibrium is a condition of balance. Changes in temperature, pressure or concentration can cause a shift in the equilibrium. Copy into Note Packet and Return to Teacher Cells and Their Environment Section 1: Passive Transport Objectives Relate concentration gradients, diffusion, and equilibrium. Predict the direction of water

More information

Movement across the Membrane

Movement across the Membrane Chapter 8. Movement across the Membrane 2003-2004 1 Cell membrane Cells have an inside & an outside Cell membrane is the boundary Can it be an impenetrable boundary? NO! Why not? The cell needs materials

More information

Movement Through the Cell Membrane

Movement Through the Cell Membrane Movement Through the Cell Membrane Cellular Movement All living organisms rely on diffusion Get oxygen for respiration Removing waste products Transpiration in plants Cellular Movement The cell membrane

More information

1. I can explain the structure of ATP and how it is used to store energy.

1. I can explain the structure of ATP and how it is used to store energy. 1. I can explain the structure of ATP and how it is used to store energy. ATP is the primary energy molecule for the cell. It is produced in the mitochondria during cellular respiration, which breaks down

More information

I. Membrane Structure Figure 1: Phospholipid. Figure 1.1: Plasma Membrane. Plasma Membrane:

I. Membrane Structure Figure 1: Phospholipid. Figure 1.1: Plasma Membrane. Plasma Membrane: I. Membrane Structure Figure 1: Phospholipid Figure 1.1: Plasma Membrane Plasma Membrane: 1 II. Early Plasma Membrane Models Figure 2: Davson-Danielli Sandwich Model In the 1960 s new evidence suggested

More information

Constant Motion of Molecules. Kinetic Theory of Matter Molecules move randomly and bump into each other and other barriers

Constant Motion of Molecules. Kinetic Theory of Matter Molecules move randomly and bump into each other and other barriers CELL TRANSPORT Constant Motion of Molecules Kinetic Theory of Matter Molecules move randomly and bump into each other and other barriers Solution homogenous liquid throughout which two or more substances

More information

FIGURE A. The phosphate end of the molecule is polar (charged) and hydrophilic (attracted to water).

FIGURE A. The phosphate end of the molecule is polar (charged) and hydrophilic (attracted to water). PLASMA MEMBRANE 1. The plasma membrane is the outermost part of a cell. 2. The main component of the plasma membrane is phospholipids. FIGURE 2.18 A. The phosphate end of the molecule is polar (charged)

More information

UNIT 4 CELL BOUNDARIES AND TRANSPORT. Unit 4 test: October 16, 2018

UNIT 4 CELL BOUNDARIES AND TRANSPORT. Unit 4 test: October 16, 2018 UNIT 4 CELL BOUNDARIES AND TRANSPORT Unit 4 test: October 16, 2018 Cell Wall CELL BOUNDARIES support protect & the cell cell membrane Lies outside of the Is made of & carbohydrates proteins Plant cell

More information

5.6 Diffusion, Membranes, and Metabolism

5.6 Diffusion, Membranes, and Metabolism 5.6 Diffusion, Membranes, and Metabolism Concentration of a substance Number of atoms or molecules in a given volume Concentration gradient of a substance A difference in concentration between two regions

More information

BSC Exam I Lectures and Text Pages

BSC Exam I Lectures and Text Pages BSC 2010 - Exam I Lectures and Text Pages I. Intro to Biology (2-29) II. Chemistry of Life Chemistry review (30-46) Water (47-57) Carbon (58-67) Macromolecules (68-91) III. Cells and Membranes Cell structure

More information

Unit 2: More on Matter & Energy in Ecosystems. Macromolecules to Organelles to Cells

Unit 2: More on Matter & Energy in Ecosystems. Macromolecules to Organelles to Cells IN: Unit 2: More on Matter & Energy in Ecosystems Macromolecules to Organelles to Cells Where are cells on the biological scale? Sub-Atomic Particles Atoms Molecules Macromolecules (proteins, lipids, nucleic

More information

Cell Membranes Valencia college

Cell Membranes Valencia college 6 Cell Membranes Valencia college 6 Cell Membranes Chapter objectives: The Structure of a Biological Membrane The Plasma Membrane Involved in Cell Adhesion and Recognition Passive Processes of Membrane

More information

Chapter 5 Homeostasis and Cell Transport

Chapter 5 Homeostasis and Cell Transport Chapter 5 Homeostasis and Cell Transport Palabra Palooza! Role #1: The Definer says: The word can be explained as Role #2: The Re-stater says: Then I understand (word) to mean Words: Passive transport

More information

Membrane Structure and Function. Cell Membranes and Cell Transport

Membrane Structure and Function. Cell Membranes and Cell Transport Membrane Structure and Function Cell Membranes and Cell Transport 1895 1917 1925 Membrane models Membranes are made of lipids Phospholipids can form membranes Its actually 2 layers - there are proteins

More information

CELL MEMBRANES. CELL MEMBRANE- Structure and Function

CELL MEMBRANES. CELL MEMBRANE- Structure and Function BIOLOGY 12 CELL MEMBRANES NAME: INTRODUCTION 1. The cell membrane the passage of molecules into and out of the cell. 2. Some types of molecules, particularly molecules, pass freely across the cell membrane

More information

How Things Get In and Out of Cells, or gummy bears, zip lock bags or whatever!

How Things Get In and Out of Cells, or gummy bears, zip lock bags or whatever! How Things Get In and Out of Cells, or gummy bears, zip lock bags or whatever! SC.912.L.14.3 Benchmark Clarifications: Students will compare and/or contrast the structures found in plant cells and in animal

More information

Lecture Overview. Cell Membrane. Marieb s Human Anatomy and Physiology. Chapter 3 Cell Membranes Movement Across the Cell Membrane Lecture 7

Lecture Overview. Cell Membrane. Marieb s Human Anatomy and Physiology. Chapter 3 Cell Membranes Movement Across the Cell Membrane Lecture 7 Marieb s Human Anatomy and Physiology Marieb Hoehn Chapter 3 Cell Membranes Movement Across the Cell Membrane Lecture 7 1 The cell membrane Lecture Overview Osmotic pressure and tonicity Movement of substances

More information

Cell Membrane Structure and Function. What is the importance of having a cell membrane?

Cell Membrane Structure and Function. What is the importance of having a cell membrane? Cell Membrane Structure and Function What is the importance of having a cell membrane? I. Membrane Structure a. Membranes contain proteins, lipids, and carbohydrates (which are all types of macromolecules)

More information

Biology, Friday, September 29

Biology, Friday, September 29 Biology, Friday, September 29 On page 62 of your INB, in the top box, write the following questions on the left and answer it on the right. What is the function of the cell membrane? Your Answer Here Micrographs

More information

Membrane Structure and Function

Membrane Structure and Function Chapter 7 Membrane Structure and Function PowerPoint Lecture Presentations for Biology Eighth Edition Neil Campbell and Jane Reece Lectures by Chris Romero, updated by Erin Barley with contributions from

More information

Cytoskeleton. Provide shape and support for the cell. Other functions of the cytoskeleton. Nucleolus. Nucleus

Cytoskeleton. Provide shape and support for the cell. Other functions of the cytoskeleton. Nucleolus. Nucleus Chapter 4: Cell Structure and Function Cytoskeleton The cytoskeleton is a network of fibers that organizes structures and activities in the cell. Microtubules (the largest) Intermediate fibers Microfilaments

More information

Passive Cellular Transport. Unit 2 Lesson 4

Passive Cellular Transport. Unit 2 Lesson 4 Unit 2 Lesson 4 Students will be able to: Define passive transport Enumerate the three types of passive transport Described each type of passive transport: osmosis, diffusion, and facilitated diffusion

More information

Concept 7.5: Bulk transport across the plasma membrane occurs by exocytosis and endocytosis

Concept 7.5: Bulk transport across the plasma membrane occurs by exocytosis and endocytosis Concept 7.5: Bulk transport across the plasma membrane occurs by exocytosis and endocytosis Small molecules and water enter or leave the cell through the lipid bilayer or by transport proteins Large molecules,

More information

Ch7: Membrane Structure & Function

Ch7: Membrane Structure & Function Ch7: Membrane Structure & Function History 1915 RBC membranes studied found proteins and lipids 1935 membrane mostly phospholipids 2 layers 1950 electron microscopes supported bilayer idea (Sandwich model)

More information

Membranes. Chapter 5. Membrane Structure

Membranes. Chapter 5. Membrane Structure Membranes Chapter 5 Membrane Structure Lipid Bilayer model: - double phospholipid layer - Gorter & Grendel: 1925 Fluid Mosaic model: consist of -phospholipids arranged in a bilayer -globular proteins inserted

More information

Cell membrane & Transport. Dr. Ali Ebneshahidi Ebneshahidi

Cell membrane & Transport. Dr. Ali Ebneshahidi Ebneshahidi Cell membrane & Transport Dr. Ali Ebneshahidi Cell Membrane To enclose organelles and other contents in cytoplasm. To protect the cell. To allow substances into and out of the cell. To have metabolic reactions

More information

The Plasma Membrane. 5.1 The Nature of the Plasma Membrane. Phospholipid Bilayer. The Plasma Membrane

The Plasma Membrane. 5.1 The Nature of the Plasma Membrane. Phospholipid Bilayer. The Plasma Membrane 5.1 The Nature of the Plasma Membrane The Plasma Membrane Four principal components in animals Phospholipid bilayer Molecules of cholesterol interspersed within the bilayer. Membrane proteins embedded

More information

Unit 2 Warm Ups. Equilibrium

Unit 2 Warm Ups. Equilibrium Unit 2 Warm Ups Equilibrium 1. Cell wall 2. Mitochondria 3. Chloroplast 4. Vesicle 5. Vacuole 6. Rough Endoplasmic Reticulum 7. Smooth Endoplasmic Reticulum 8. Cytoskeleton 9. Lysosomes 10.Cell Membrane

More information

Outline. Membrane Structure and Function. Membrane Models Fluid-Mosaic. Chapter 5

Outline. Membrane Structure and Function. Membrane Models Fluid-Mosaic. Chapter 5 Membrane Structure and Function Chapter 5 Membrane Models Fluid-Mosaic Outline Plasma Membrane Structure and Function Protein Functions Plasma Membrane Permeability! Diffusion! Osmosis! Transport Via Carrier

More information

Ch 3 Membrane Transports

Ch 3 Membrane Transports Ch 3 Membrane Transports what's so dynamic about cell membranes? living things get nutrients and energy from the envrionment this is true of the entire organism and each cell this requires transport in/out

More information

Membrane Structure and Function. Chapter 5

Membrane Structure and Function. Chapter 5 Membrane Structure and Function Chapter 5 Plasma Membrane So far we ve discussed the phospholipid bilayer of the plasma membrane and the presence of glycolipids and glycoproteins There are multiple types

More information

Section 4: Cellular Transport. Cellular transport moves substances within the cell and moves substances into and out of the cell.

Section 4: Cellular Transport. Cellular transport moves substances within the cell and moves substances into and out of the cell. Section 4: Cellular transport moves substances within the cell and moves substances into and out of the cell. Essential Questions What are the processes of diffusion, facilitated diffusion, and active

More information

Describe the Fluid Mosaic Model of membrane structure.

Describe the Fluid Mosaic Model of membrane structure. Membranes and Cell Transport All cells are surrounded by a plasma membrane. Eukaryotic cells also contain internal membranes and membranebound organelles. In this topic, we will examine the structure and

More information

II. Active Transport (move molecules against conc. gradient - cell must expend energy) (uses carrier proteins)

II. Active Transport (move molecules against conc. gradient - cell must expend energy) (uses carrier proteins) Chapter 5 - Homeostasis and Transport I. Passive Transport (no energy from cell required) A. Diffusion 1. movement of molecules from an area of higher concentration to an area of lower concentration a.

More information

Membranes. Chapter 5

Membranes. Chapter 5 Membranes Chapter 5 Membrane Structure The fluid mosaic model of membrane structure contends that membranes consist of: -phospholipids arranged in a bilayer -globular proteins inserted in the lipid bilayer

More information

Chapter 1 Plasma membranes

Chapter 1 Plasma membranes 1 of 5 TEXTBOOK ANSWERS Chapter 1 Plasma membranes Recap 1.1 1 The plasma membrane: keeps internal contents of the cell confined to one area keeps out foreign molecules that damage or destroy the cell

More information

Cell Membrane: a Phospholipid Bilayer. Membrane Structure and Function. Fluid Mosaic Model. Chapter 5

Cell Membrane: a Phospholipid Bilayer. Membrane Structure and Function. Fluid Mosaic Model. Chapter 5 Membrane Structure and Function Chapter 5 Cell Membrane: a Phospholipid Bilayer Phospholipid Hydrophilic Head Hydrophobic Tail Lipid Bilayer Fluid Mosaic Model Mixture of saturated and unsaturated fatty

More information

Membrane Structure and Function - 1

Membrane Structure and Function - 1 Membrane Structure and Function - 1 The Cell Membrane and Interactions with the Environment Cells interact with their environment in a number of ways. Each cell needs to obtain oxygen and other nutrients

More information

Membrane Structure. Membrane Structure. Membrane Structure. Membranes

Membrane Structure. Membrane Structure. Membrane Structure. Membranes Membrane Structure Membranes Chapter 5 The fluid mosaic model of membrane structure contends that membranes consist of: -phospholipids arranged in a bilayer -globular proteins inserted in the lipid bilayer

More information

BIOLOGY 12 - Cell Membrane and Cell Wall Function: Chapter Notes

BIOLOGY 12 - Cell Membrane and Cell Wall Function: Chapter Notes BIOLOGY 12 - Cell Membrane and Cell Wall Function: Chapter Notes The cell membrane is the gateway into the cell, and must allow needed things such as nutrients into the cell without letting them escape.

More information

The Cell Membrane. Lecture 3a. Overview: Membranes. What is a membrane? Structure of the cell membrane. Fluid Mosaic Model. Membranes and Transport

The Cell Membrane. Lecture 3a. Overview: Membranes. What is a membrane? Structure of the cell membrane. Fluid Mosaic Model. Membranes and Transport Lecture 3a. The Cell Membrane Membranes and Transport Overview: Membranes Structure of cell membranes Functions of cell membranes How things get in and out of cells What is a membrane? Basically, a covering

More information

3.2.3 Transport across cell membranes

3.2.3 Transport across cell membranes alevelbiology.co.uk 3.2.3 Transport across cell membranes SPECIFICATION The basic structure of all cell membranes, including cell-surface membranes and the membranes around the cell organelles of eukaryotes,

More information

The Cell Membrane. Why cells must control materials. Living cells must maintain homeostasis for survival.

The Cell Membrane. Why cells must control materials. Living cells must maintain homeostasis for survival. The Cell Membrane Why cells must control materials Living cells must maintain homeostasis for survival. The cell membrane is the boundary between the cell and its environment. It is the cell membrane s

More information

BIOLOGY 12 - Cell Membrane and Cell Wall Function: Chapter Notes

BIOLOGY 12 - Cell Membrane and Cell Wall Function: Chapter Notes BIOLOGY 12 - Cell Membrane and Cell Wall Function: Chapter Notes The cell membrane is the gateway into the cell, and must allow needed things such as nutrients into the cell without letting them escape.

More information

Membrane Structure and Function

Membrane Structure and Function Membrane Structure and Function Chapter 7 Objectives Define the following terms: amphipathic molecules, aquaporins, diffusion Distinguish between the following pairs or sets of terms: peripheral and integral

More information

Biology 12 Cell Structure and Function. Typical Animal Cell

Biology 12 Cell Structure and Function. Typical Animal Cell Biology 12 Cell Structure and Function Typical Animal Cell Vacuoles: storage of materials and water Golgi body: a series of stacked disk shaped sacs. Repackaging centre stores, modifies, and packages proteins

More information

The Cell Membrane & Movement of Materials In & Out of Cells PACKET #11

The Cell Membrane & Movement of Materials In & Out of Cells PACKET #11 1 February 26, The Cell Membrane & Movement of Materials In & Out of Cells PACKET #11 Introduction I 2 Biological membranes are phospholipid bilayers with associated proteins. Current data support a fluid

More information

WAYS MOLECULES MOVE. Chapter 7-3.

WAYS MOLECULES MOVE. Chapter 7-3. WAYS MOLECULES MOVE Chapter 7-3 http://www.biology4kids.com/files/cell_main.html See a video clip about DIFFUSION-7A Diffusion http://lhs.lps.org/staff/sputnam/biology/u3cell/diffusion_1.png Animatioin

More information