MODULE 6: Lipids and Membranes, Lectures 13-14
Quadrant - 2
Animations:
cell membrane
www.johnkyrk.com/cellmembrane.html
The lipid membrane is an elaborate example of a well-known fact : oil and ...
Membrane structure relies on the tendency of fatty acid molecules. trans would.
Cell Membrane Animation - YouTube ► 3:31► 3:31
www.youtube.com/watch?v=5GO8Nj1vKmA
Feb 2, 2012 - Uploaded by Unstung. From Wikipedia: "The cell membrane or plasma
membrane is a biological membrane ... It consists of ...
Lipids & Membranes
https://www.rpi.edu/dept/bcbp/molbiochem/MBWeb/mb1/.../lipid.htm
Most membrane lipids are amphipathic, having a non-polar end and a polar end. .... the
plane of a membrane, is depicted at right and in the animation provided.
Graphics Gallery: Lipids & Membranes - Swiss PDB Viewer
spdbv.vital-it.ch/TheMolecularLevel/BiochemViews/LipMemb/
They are part of a RasMol animation of lipids and bilayers, available at the RasMol
Home Page. ... Cholesterol is a normal component of cell membranes.
Biological Membranes and the Cell Surface
www.uic.edu/classes/bios/bios100/lectures/membranes.htm
The membrane is a fluid mosaic of phospholipids arranged in a lipid bilayer and ...
Animation - this is an excellent animation describing lipid bilayer formation ...
Biological Animations - St. Olaf College
www.stolaf.edu/people/giannini/biological%20anamations.html
(short animations of biological processes) ... -protein folding. Lipids. Carbohydrates. membrane fluidity · -glucose in water. Enzymes. Membrane Transport.
Plasma Membrane Contained Lipid Rafts - DnaTube.com - Scientific. ► 1:41► 1:41
www.dnatube.com/.../Plasma-Membrane-Contained-Li...
Lipid Rafts are said to be involved in the regulation of signal transduction.
Chem 146 - Membrane Biochemistry
web.chem.ucsb.edu/~molvisual/ABLE/membrane_biochem/
Membrane Protein Folding And Stability: Physical Principles ...
http://www.uwsp.edu/chemistry/tzamis/boxanim.gif, Dynamic animation of beta
oxidation of lipids.
Membranes - McGraw-Hill Higher Education
highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter6/
6.1 Biological membranes are fluid layers of lipid. The Phospholipid Bilayer •
Biological membranes are composed of phospholipid bilayers with .... Animations
Page 1 of 16
Membrane Structure and Function - Biol230W Fall09 - Confluence
https://wikispaces.psu.edu/display/.../Membrane+Structure+and+Function
Aug 21, 2009 - Membranes are a Mosaic of Lipids and Proteins; Lipid Composition of a
.... more rapidly and be found further from the origin (see animation).
Plasma Membrane Animation Techniques - Molecular Movies
www.molecularmovies.com/img/pdf_tutorials/paintFx_membranes.pdf
large number of objects need to be seen from a distance (in this particular situation, the
number of lipids on the surface of the membrane). Lets start by designing ...
Lipids and Biological Membranes - OSCAR Main Page
oscar.iitb.ac.in/availableProposalsAction1.do?...%20Lipids%20and%20B...
Open source Learning Objects (LOs) / Animations. ... Summary: Biological membranes
that define the boundaries of cells are ... Lipids are one of the four important classes of
biomolecules that have a variety of structural and functional roles.
Construction of the Cell Membrane - Wisc-Online.com
https://www.wisc-online.com/ViewObject.aspx?ID=AP1101
The student studies the structure of the cell membrane by constructing it using the
correct molecules. ... 10/17/2008, I found this animation really helpful. And the ...
Animations
www.ohsu.edu/research/skachlab/animations.shtml
Protein translocation and biogenesis in the ER is a dynamic process that ... in an
aqueous environment, shielded from membrane lipids during translocation.
Lipids
bioweb.wku.edu/courses/biol115/wyatt/biochem/lipid/Lipid_2.asp
Phospholipids serve an extremely important function in our bodies, they form the cell
membrane. Think of each cell as being surrounded by a fence, a fluid fence ...
Cell Biology: cell membranes
biologyofcells.blogspot.com › pinocytosis › proteasome › pumps
Dec 22, 2007 - Lipid rafts are mobile areas within cell membranes that are more rigid
than ... Џ beautiful Flash 8 animation - Inner Life of the Cell, which shows ...
Lecture - 13 Lipids and Membranes 1 - Free Medical Video Lecture
www.learnerstv.com/video/Free-video-Lecture-1400-medical.htm
Free Lecture - 13 Lipids and Membranes 1 video lecture. ... Video Lectures, Video
Courses, Science Animations, Lecture Notes, Online Test, Lecture ...
Membrane Lecture Notes - University of Minnesota Duluth
www.d.umn.edu/~sdowning/Membranes/lecturenotes.html
[Lecture Notes | Image Index | Animation Index | Home Page]. Membranes ... 1. most
abundant of the lipids in membranes: form a lipid bilayer 2. phospholipid ...
Cell Membranes: Chapt. 6
chs.sd57.bc.ca/~jbleecker/...1/C4_Membranes/Membranes_Teacher.ppt
ANIMATION OF THE CELL MEMBRANE ... Protein-coated pores extend through
membrane (MOSAIC). Pores are very small ... Membrane Lipids. Composed ...
Page 2 of 16
Cell Membranes
local.brookings.k12.sd.us/krscience/open/cells/APCh7membranesme.ppt
Animation from: http://www.sp.uconn.edu/~terry/images/anim/fluidmem.gif. Click here
to See ... stick in the lipid membrane; anchors the protein in membrane.
Illustrations:
Bilayer Lipid Membrane Stock Illustrations | Getty Images US
www.gettyimages.co.nz/.../bilayer-lipid-membrane-stock-illustrations
View and license bilayer lipid membrane stock photos, illustrations and other Creative
photography from Getty Images.
Membranes - Ohio State University at Mansfield
www.mansfield.ohio-state.edu/~sabedon/biol1050.htm
Jump to cell (biological) membrane, illustration - Illustration, cell (biological)
membrane ... In addition to amphipathic lipid-based molecules (such ...
Lipids Clip Art and Stock Illustrations. 134 Lipids EPS illustrations ...
www.canstockphoto.com/illustration/lipids.html
Downloads for just $1.00, with thousands of images added daily. Subscriptions ...
Ceramide cell membrane lipid, molecular model Stock Illustrations. Lipid A ...
Procaryote Cell Walls and Membranes
mansfield.osu.edu/~sabedon/biol1080.htm
Illustration, gram-positive cell envelope ... Illustration, gram-negative cell envelope ...
LPS is anchored into the outer membrane by a lipid portion called lipid A.
Lipids - [email protected]
biology.tutorvista.com/biomolecules/lipids.html
... chemical composition. Illustration of Lipids Classification ... Phosphoglycerides are
major phospholipids, they are found in membranes. It contains fatty acid ...
Lipids, Membranes & Vesicle Trafficking - BioChemWeb.org by ...
biochemweb.org/lipids_membranes.shtml
by Gabriel Fenteany, This page is an annotated index of major online resources dealing
with lipids and ... On-Line Biology Book - Information and illustrations by M.J.
Farabee.
Membrane Lipid
cr.middlebury.edu/biology/labbook/membranes/.../membranes/chap2.ht...
Lipids make up the bulk of biological membranes, and it's reasonable to ... plasma
membrane lipid is cholesterol, a sterol, which is illustrated below; this cartoon ...
Biophysical interactions with model lipid membranes: applications in ...
www.ncbi.nlm.nih.gov › Journal List › NIHPA Author Manuscripts
by C Peetla - 2009 - Cited by 78 - Related articles
In recent years, model lipid membranes have also been explored to ... Fig. 1. Schematic
illustration of cell membrane and different model membrane systems ...
Page 3 of 16
Diffusional transport in responding lipid membranes†
www.uam.es/personal_pdi/ciencias/mvelez/.../TransportAcross.pdf
by E Sparr - 2009 - Cited by 7 - Related articles
Diffusional transport across lipid membranes can be highly complex and include several
parallel ... This is illustrated for a lipid membrane in the presence of.
Lipids and Membrane Proteins - David Case' group
casegroup.rutgers.edu/lnotes/memprotb10.pdf
Fundamentals of lipid/membrane structure. Fundamentals of membrane protein
structure ... Illustration of the lateral pressure, p(z), profile in a lipid bilayer.
Molecule Illustrations - Wayne's Word
waynesword.palomar.edu/molecu1.htm
Jump to Fluid-Mosaic Model Of Cell Membrane - 4. Fluid-Mosaic Model Of
Membrane Structure ... Insulin stimulates glucose uptake by fat and muscle cells ...
Lipids Stock Photos, Lipids Stock Photography, Lipids Stock Images ...
www.shutterstock.co.in/s/lipids/search.html
Results 1 - 100 of 514 - Download lipids stock photos, vectors, and illustration at
affordable rates. Search over ... Ceramide cell membrane lipid, molecular model.
Lipid Stock Photos Images, Royalty Free Lipid Images And Pictures
www.123rf.com/stock-photo/lipid.html
Matches 1 - 60 of 256 - lipid Search and download from millions of HD stock ...
Cholesterol molecular structure. 12415451. Structure of plasma membrane. 12595552.
Membrane Stock Photo Images. 2345 membrane royalty free ...
www.fotosearch.com/photos-images/membrane.html
Download 2345 Membrane images and stock photos. ... Ceramide cell membrane lipid,
molecular model ... fractal illustration of feathers and membranes.
The effect of lipid extraction on electron-microscopic images of plant ...
www.nrcresearchpress.com/doi/abs/10.1139/b73-153
by ES Swanson - 1973 - Cited by 5 - Related articles
Abstract. An evaluation was made of the role of lipids in electron-microscopic
membrane images of plant cells by comparing extracted lipids with changes in the ...
Study of the Structure, Thermodynamics, and Kinetics of Lipid ...
books.google.co.in/books?isbn=0549105867
LIST OF FIGURES Figure Page 2.1 Illustration of sum-frequency generation (SFG)
(top) and energy level diagram of SFG (bottom). 9 2.2 Schematic of optical ...
Lipid rafts: phase separation in lipid bilayers studied - JPK ...
www.jpk.com/jpk-app-lipid-phase1.download.d422b5be570ee6f57934e...
cholesterol was used as a model raft-forming membrane. ... Such a phase separated
bilayer is illustrated .... images show contrast between the lipid phases.
Schematic illustration of attachment of bilayer lipid membranes and ...
www.springerimages.com/Images/RSS/1-10.1007_s00216-004-2611-4-1
SpringerImages - Schematic illustration of attachment of bilayer lipid membranes and
lipid monolayer to solid support [28]
Page 4 of 16
Video demonstrations:
Lipids and Membranes 1 Video Lecture, IIT Kharagpur
freevideolectures.com › ... › IIT Kharagpur
Lipids and Membranes 1 Video Lecture, IIT Kharagpur Course, Bio Technology,
Youtube Free Download ...
Lipids and Membranes II Video Lecture, IIT Kharagpur
freevideolectures.com › ... › IIT Kharagpur
Lipids and Membranes II Video Lecture, IIT Kharagpur Course, Bio Technology,
Youtube Free Download ...
Cell Membrane - The Lipid Bilayer - YouTube ► 10:10► 10:10
www.youtube.com/watch?v=9ILSsW3tXr8
Oct 28, 2012 - Uploaded by Armando Hasudungan. What is a lipid, how does it form a
membrane? What is a fluid mosaic ... Alert icon. You need Adobe Flash ...
Lipids - YouTube ► 1:54► 1:54
www.youtube.com/watch?v=7k2KAfRsZ4Q
Apr 21, 2009 - Uploaded by garlandscience... This video describes the structure and
characteristics of lipids and the ... Cell Membrane - The Lipid ...
Lecture - 13 Lipids and Membranes 1 - Free Medical Video Lecture
www.learnerstv.com/video/Free-video-Lecture-1400-medical.htm
Free Lecture - 13 Lipids and Membranes 1 video lecture.
Video - Lecture - 13 Lipids and Membranes 1 - Foldit Wiki - a Wikia ...
foldit.wikia.com/wiki/File:Lecture_-_13_Lipids_and_Membranes_1
Lecture - 13 Lipids and Membranes 1. Edit · History ... Thought I would start a page
linking through to some Biochem videos for anyone that is... See full list > ...
Video - Lecture - 14 Lipids and Membranes II - Foldit Wiki - a Wikia ...
foldit.wikia.com/wiki/File:Lecture_-_14_Lipids_and_Membranes_II
This file contains additional information, probably added from the digital camera or
scanner used to create or digitize it. If the file has been modified from its ...
CELL MEMBRANE – LIPID BILAYER – VIDEO | biologypop
biologypop.com/cell-membrane-lipid-bilayer-video/
Lipid bilayers form through the process of self-assembly. The cell membrane consists
primarily of a thin layer of amphipathic phospholipids which spo.
Reconstitution of a Kv Channel into Lipid... | Video Protocol - JoVE ► 0:10► 0:10
www.jove.com/video/.../reconstitution-kv-channel-i...
Procedures for complete reconstitution of a prototype voltage-gated potassium channel
into lipid membranes ...
05 Lipids and Biological Membranes - Yovisto ► 40:43► 40:43
www.yovisto.com/video/11758
[video:11758] Bookmark and Share. Title: 05 Lipids and ... Description: Part 1 of a
lecture covering an ...
Page 5 of 16
Fats and Lipids - Chemistry Video by Brightstorm ► 3:25► 3:25
www.brightstorm.com/science/.../fats-and-lipids/
Time-saving Brightstorm video description of a lipid. Video on the different parts of a
lipid including wax ...
Lecture 6 7 lipids and membranes - SlideShare
www.slideshare.net/.../lecture-6-7-lipids-and-membranes
Mar 29, 2012 - Lecture 6 7 lipids and membranes Presentation Transcript. Lipids and
Membranes; Membranes They function to organize biological systems ♣:...
Structure and Function of Lipids - Free Intro to Biology Video ► 8:23► 8:23
education-portal.com/.../structure-and-function-of-li.... They can be fats, oils, or
hormones, and even exist in our cell membranes. Learn more about the chemical ...
Video lecture : Lipids and Membranes 1 | Biology Free Videos
biologyfreevideos.wordpress.com/.../video-lecture-lipids-and-membrane...
Dec 3, 2010 - The lipids are important constituents of the diet because of their high
energy value and also because of the fat-soluble vitamins and the ...
Quadrant -3
Multiple Choice questions – chose the correct answer:
Principal classes of membrane proteins include all of the following except
a) receptors
b) cell surface markers
c) spectrins
d) transport proteins
2. Which of the following are not components of the cell membrane?
a) cell surface markers
b) transmembrane proteins
c) interior protein network
d) plasmodesmata
3. To cross the cell membrane, water must
a) squeeze between phospholipid molecules
b) pass through aquaporins
c) be transported at the expense of ATP
d) be moved by a cotransport system
Page 6 of 16
4. If a cell's contents are greatly hypoosmotic to the surrounding environment, the cell will
probably
a) expand
b) become isotonic
c) burst
d) shrivel
5. The sodium-potassium pump passes
a) more Na+ out than K+ in
b) K+ out and Na+ in on a one-for-one basis
c) Na+ out and K+ in on a one-for-one basis
d) K+ and Na+ in the same direction
6. Exocytosis is a process by which cells
a) pass substances out of the cell in vesicles
b) pass substances out of the cell through the membrane by osmosis
c) release substances directly into the extracellular fluid through a pore
d) release substances directly into the extracellular fluid through a pit
7. A phospholipid has
a) a phosphate group in place of one fatty acid
b) phosphate groups in place of two fatty acids
c) phosphate groups in place of three fatty acids
d) a phosphate group in place of a carbon in glycerol
8. Clathrin-coated pits are used to
a) allow desired molecules directly into the cytoplasm
b) pass wastes in vesicles to the outside.
c) pass information into adjacent cells
d) bring desired substances from the environment into the cell in vesicles
9. A lipid bilayer
a) permits water soluble molecules to pass through it
b) facilitates the passage of water soluble molecules through it
c) inhibits the passage of water soluble substances through it
d) actively transports water soluble molecules through it
10. A cell is recognized by other tissue members as "self" by its surface
a) glycolipids
b) glycoproteins
c) ketoglutaric acids
d) glycocarbohydrates
Page 7 of 16
11. A net gain of water tends to occur
a) in a hypoosmotic solution from an isosmotic solution
b) in an isosmotic solution from a hyperosmotic solution
c) in a hyperosmotic solution from a hypoosmotic solution
d) in a hypoosmotic solution from a hyperosmotic solution
12. Red blood cells have a characteristic concave shape because of
a) spectrin
b) dextrin
c) hemoglobin
d) hemocyanin
13. Transmembrane proteins are
a) always abundant
b) often not fixed in position
c) never abundant
d) none of the above
14. Cystic fibrosis results from defective ion channels for
a) Na+
b) Clc) Ca++
d) ClO 3 e) H+
15. Fluidity of phospholipid bilayer is increased by
a) double bonds between carbon atoms in the fatty acid tails
b) steroid lipids at certain temperatures
c) cholesterol at certain temperatures
d) all of the above
16. A cell engaged in phagocytosis must be
a) engulfing a live organism
b) engulfing a dead organism
c) transporting bulk dissolved nutrients
d) transporting bulk solid material
17. A, B, and O blood groups are marked by surface
a) glycoproteins
b) glycolipids
c) glycocarbohydrates
d) gluterates
Page 8 of 16
18. In a lipid bilayer the lipids have
a) their water repelling heads facing inward
b) their water repelling tails facing inward
c) their hydrogen bond forming tails facing inward
d) no relationship to water
19. ATP is required in the transport of
a) all molecules across a membrane
b) molecules to areas of lower concentrations
c) molecules to areas of higher concentrations
d) molecules through a protein channel
20. A hypotonic solution is one whose concentration:
a) is equal to that inside a cell
b) is greater than that inside a cell
c) is less than that inside a cell
State whether True or False:
1. Sterols are the part of the membranes
2. The membrane proteins that catalyze active transport present in the cytoplasm
3. Among many components used during translation DNA is also a one of them.
4. The melting properties of fatty acids and lipid bilayers are due primarily to the
hydrophobic effect.
5. Cholesterol is essential for normal membrane functions because it keeps membranes
fluid.
6. nucleic acids is one of the component found in membranes
7. Membranes serve as a selective barrier for the cell
8. The phospholipids are unusual molecules because: they have hydrophilic and
hydrophobic regions.
9. Membrane proteins provide receptors for chemical messengers
10. Membrane carbohydrates function primarily in cell-cell recognition
11. Membrane proteins can communicate to other cells.
12. Phospholipids are the main constituents of cell membranes.
Fill in the blanks:
1. According to the fluid mosaic model of cell membranes, ____________________
molecule spans the membrane, from its inner to outer surface.
2. Micelles of fatty acids in water are organized such that the ____________ face the
solvent and the _____ are directed toward the interior
3. __________ model explaine the membrane is a lipid bilayer with proteins dispersed
within it.
4. Smooth endoplasmic reticulum primarily functions in __________________
Page 9 of 16
5. _________________ plasma membrane possesses a charged polar "head" and an
uncharged non-polar "tail"?
6. Proteins destined for export from the cell are synthesized on
______________________
7. The main difference between saturated and unsaturated fatty acids is _____________
8. ________________ that may function as a cellular ID tag, allowing cells of the
immune system to recognize a cell as native to the body.
9. ___________________ are microscopic vesicles consisting of an aqueous core
enclosed in one or more phospholipid layers.
10. An example for lipid soluble vitamin is _________________________
11. Saturated fatty acids have ________________ melting points.
12. the presence of both hydrophilic (CO 2 ) and hydrophobic (alkyl) regions in the same
molecule is termed as _____________________
Quadrant – 4
Answers are only indicative – Expand on the outlines given:
1.
2.
3.
4.
5.
What is the lipid bilayer?
Briefly describe different activities of the lipid bilayer
Explain with diagram the structure of the lipid bilayer
Illustrate the phospholipid bilayer
What are the components found in the membrane other than the channel proteins and
lipid bilayer?
6. Explain the fluid mosaic model proposed by Singer and Nicholson (1972)
7. What roles the protein channels play in the membranes?
8. Discuss briefly on the membrane transporters
Supplementary reading:
1. Lodish H, Berk A, Zipursky LS, et al. (2004) Molecular Cell Biology (4th ed.). New
York: Scientific American Books. ISBN 0-7167-3136-3.
2. Jesse Gray, Shana Groeschler, Tony Le, Zara Gonzalez (2002) "Membrane Structure"
(SWF). Davidson College. Retrieved 2007-01-11.
3. Sleytr, U.B., D. Pum, E.M. Egelseer, N. Ilk, B. Schuster (2013) S-Layer Proteins.
In: Knoll, W. (ed.) Handbook of Biofunctional Surfaces, Pan Stanford Publishing,
Singapore; ISBN 978-981-4316-63-7, pp. 507-568.
4. Kimball's Biology pages, Cell Membranes
5. Budin, Itay; Devaraj, Neal K. (December 29, 2011). "Membrane Assembly Driven by
a Biomimetic Coupling Reaction". Journal of the American Chemical Society. 134 (2)
(2): 751–753. doi:10.1021/ja2076873. Retrieved February 18, 2012.
Page 10 of 16
6. Singer SJ, Nicolson GL (Feb 1972). "The fluid mosaic model of the structure of cell
membranes". Science 175 (4023): 720–31. doi:10.1126/science.175.4023.720.
PMID 4333397.
7. Schrems, A., V.D. Larisch, C. Stanetty, K. Dutter, S. Damiati, U.B. Sleytr, B.
Schuster. (2011) Liposome Fusion on Proteinaceous S-layer Lattices Triggered via βdiketone ligand – Europium(III) Complex Formation. Soft Matter 7: 5514-5518. [Full
text BOKU-login]
8. Schrems, A., A. Kibrom, S. Küpcü, E. Kiene, U.B. Sleytr, B. Schuster. (2011) Bilayer
lipid membrane formation on a chemically modified S-layer lattice. Langmuir 27:
3731-3738. [Full text BOKU-login]
9. Schuster, B and U.B. Sleytr. (2009) Composite S-Layer Lipid Structures. J. Struct.
Biol. 168: 207-216. [Full text BOKU-login]. "Nomenclature of Lipids". IUPAC-IUB
Commission on Biochemical Nomenclature (CBN). Retrieved 2007-03-08.
10. Chirala S, Wakil S (2004). "Structure and function of animal fatty acid synthase".
Lipids 39 (11): 1045–53. doi:10.1007/s11745-004-1329-9. PMID 15726818.
11. White S, Zheng J, Zhang Y (2005). "The structural biology of type II fatty acid
biosynthesis". Annu Rev Biochem 74: 791–831.
Wiki development on the course/other resources:
Lipids & Membranes
https://www.rpi.edu/dept/bcbp/molbiochem/MBWeb/mb1/.../lipid.htm
Lipids and Membrane Structure. Contents of this page: Fatty acids.
Glycerophospholipids Sphingolipids Bilayer membranes & membrane fluidity.
Cholesterol fatty acids - Glycerophospholipids - Sphingolipids
Membrane lipids - Wikipedia, the free encyclopedia
en.wikipedia.org/wiki/Membrane_lipids
Membrane lipids are a group of compounds (structurally similar to fats and oils) which
form the double-layered surface of all cells. The three major classes of ...
Biochemistry/Lipids And The Plasma Membrane - Wikibooks, open ...
en.wikibooks.org/wiki/.../Lipids_And_The_Plasma_Membrane
Furthermore, lipids are non-polar compound and soluble in organic solvent. Their
ability to form membranes are as a result of their hydrophobic properties, ...
Lecture 6 7 lipids and membranes - SlideShare
www.slideshare.net/.../lecture-6-7-lipids-and-membranes
Mar 29, 2012 - Lecture 6 7 lipids and membranes Presentation Transcript. Lipids and
Membranes They function to organize biological systems ♣; Membranes:...
Lipids and Membrane Proteins - David Case' group
casegroup.rutgers.edu/lnotes/memprotb10.pdf
Lipids and Membrane Proteins. Biophysical Chemistry 1, Fall 2010. Fundamentals of
lipid/membrane structure. Fundamentals of membrane protein structure.
Page 11 of 16
Lipid Bilayer Membranes - Elmhurst College
www.elmhurst.edu/~chm/vchembook/553bilayer.html
Every cell is enclosed by a membrane which gives structure to the cell and ... Cell
membranes are composed of two classes of molecules: lipids and proteins.
Lipids: Membrane Structure
www.wou.edu/~guralnl/451introLipids.pdf
Lipids: Membrane Structure. • Role of lipids. • Fatty acid structure and nomenclature. •
Types of membrane lipids. • Structure of membrane. • Membrane fluidity ...
Lipids and Membranes - BioWiki
biowiki.ucdavis.edu/Wikitexts/BIS_105%3A.../Lipids_and_Membranes
Nov 21, 2013 - Membrane Lipids. 3.1. Phospholipids; 3.2. Glycolipids and Sterols. 4.
Lipid Solubility; 5. Phase Transitions; 6. Internal Links; 7. Contributors ...
Fluid lipid membranes – a primer
www.cmu.edu/biolphys/deserno/pdf/membrane_theory.pdf
by M Deserno - Cited by 1 - Related articles
Lipid membranes are quasi-two-dimensional structures which form by ... Lipids come
in many different kinds in nature, and this is not the place to classify them ...
5.2 Lipids and Membrane Proteins in Biological Membranes | Life ...
csls-text.c.u-tokyo.ac.jp/inactive/05_02.html
Lipid is a collective term for materials that do not dissolve readily in water but do so
easily in organic solvents. The lipids that constitute biological membranes ...
Biochemistry of Lipids, Lipoproteins and Membranes, 4th Edition ...
store.elsevier.com › ... › Biochemistry and Molecular Biology › Lipids
Elsevier Store: Biochemistry of Lipids, Lipoproteins and Membranes, 4th Edition from
J.E. Vance, Dennis Vance. ISBN-9780444511386, Printbook , Release ...
Lipid Membranes
math.lanl.gov/~yi/lipid.html
Despite their differing functions, all biological membranes have a common structure: a
very thin film of lipid and protein molecules, which are able to move about ...
Membrane Lipid
cr.middlebury.edu/biology/labbook/diffusion/.../membranes/chap2.htm
Lipids make up the bulk of biological membranes, and it's reasonable to suppose their
large numbers greatly influence membrane structure and function. Indeed ...
Biological Membranes
www.ks.uiuc.edu/Services/Class/.../02-biological-membranes.pdf
Molecular models. A highly selective permeability barrier. Lipid Membranes. Internal
membranes for organelles. • Receptors, detecting the signals from outside:.
Lipid Bilayers and Cell Membranes
www.uic.edu/classes/phys/phys450/MARKO/N016.html
This section describes basic mechanical and statistical-mechanical properties of lipid
bilayers, which are the basic structures making up cell membranes.
Page 12 of 16
Lipids and Membranes - Personal.kent.edu - Kent State University
www.personal.kent.edu/~cearley/PChem/lipid/lipid.htm
Lipids and Membranes. 1 Lipids and Membranes. Outline - Chapter 9 in Text. Classes
of lipids. Fatty Acids; Triglycerides; Phospholipids; Steriods. Lipoproteins ...
BIOLOGICAL MEMBRANES - Biochemical Society
www.biochemistry.org/Portals/0/Education/Docs/BASC08_full.pdf
Biological membranes are made of three major components: lipids, proteins and ... The
third type of membrane lipid is cholesterol, a molecule that is struc-.
Membranes - Biology
biology.kenyon.edu/HHMI/Biol113/membranes.htm
The fluid mosaic model proposes that a membrane is a lipid bilayer with proteins
embedded in it. This model names lipids, proteins, and carbohydrates as the ...
Lipids, Membranes & Vesicle Trafficking - BioChemWeb.org by ...
biochemweb.org/lipids_membranes.shtml
by Gabriel Fenteany. This page is an annotated index of major online resources dealing
with lipids and membrane structure, function, dynamics and transport, vesicle transport
Solution to Quiz:
Chose the correct answer
1. C 6. A 11. D 16.
2. C 7. A 12. C 17.
3. B 8. D 13. D 18.
4. D 9. C 14. B 19.
5. A 10. B 15. C 20.
A
B
B
C
c
State whether True or False
1. T 4. T 7. T 10 T
2. F 5. T 8. T 11 T
3. F 6. F 9. 9 12 T
Fill in the Blanks
1. Transmembrane 4. Membrane synthesis 7. Double bond 10 Vit A, D
2. Head ---tail
5. Phospholipids
8. MHC
11 High
3. Fluid mosaic
6. RER
9. Liposomes
12 Amphipathic
Page 13 of 16
Answers are only indicative. Expand on the outline given:
1. What is the lipid bilayer?
The lipid bilayer (phospholipid bilayer/cell membrane) is a structural component of the
cell that isolates the cell components (organelles, cytoplasm) from the extracellular
environment.
2. Briefly describe different activities of the lipid bilayer
•
Maintain an internal environment: the external cellular environment is often
different to the cellular environment (ion, protein concentrations etc). The cell can
control its environment by controling gene expression of transmembrane proteins
(see 'crossing the membrane')
•
Allows the cell to control what enters/exits: transporter proteins and channels enable
the cell to selectively uptake molecules that it requires whilst excluding those that
may be harmful.
•
Protection: the lipid bilayer creates an envelope - housing the cellular components
and offering some protection. Some cells, such as plant cells, have a cell wall which
offers further protection.
•
Contains important components involved in cell recognition, communication,
signalling etc: the lipid bilayer is the boundary between the internal and external
environment and must mediate communication between the two.
•
Gives the cell shape (anchors with the cytoskeleton): in some cells the shape is
important. One example is the red blood cell. Its concave shape increases its surface
area allowing it to bind oxygen much more efficiently.
3. Explain with diagram the structure of the lipid bilayer
The lipid bilayer is made up of many phospholipids that align together. Each
phospholipid is made up of a hydrophilic head and a hydrophobic tail (Figure). The
most common phospholipid is phosphatidylcholine which contains a choline molecule
bound to phosphate and glycerol. The hydrophilic head is polar allowing it to form
hydrogen bonds with water molecules, whereas the tail region - made from two
hydrocarbon chains - is non-polar or hydrophobic. It is this combination of both a
hydrophobic and hydrophilic region (amphiphilic) that gives phospholipids such an
important function within the cell. When placed in water, the phospholipid molecules
naturally align into a bilayer (figure 2), allowing the hydrophobic tails to avoid water
whilst the hydrophilic heads form hydrogen bonds with water molecules. Interestingly,
the lipid bilayer will form a closed sphere (liposome) to completely exclude water from
the hydophobic tail.
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4. Illustrate the phospholipid bilayer
The lipid-bilayer isolates the internal components of the cell from the extracellular
environment. Whilst lipid-soluble molecules can cross the membrane directly through
the bilayer, this is not so for large molecules such as glucose, water and other polar
molecules. Transmembrane proteins are anchored throughout the entire bilayer and
allow non-polar molecules to cross the membrane, facillitating the passing of these
molecules into or out of the cell. These proteins not only allow essential components into
the cell, they also offer an opportunity for the cell to control what can and cannot enter.
The cell can tightly control what can and cannot enter the cell by altering the expression
of genes encoding transmembrane proteins.
5. What are the components found in the membrane other than the channel proteins
and lipid bilayer?
Along with the various kinds of transporter proteins, other molecules are found within
the lipid bilayer that are of functional importance to the cell and include:
•
Cholesterol - provides support and reduces permeability.
•
Other proteins: Glycoproteins and Antigens
Many of the molecules associated with the lipid bilayer help link the extracellular
environement with the intracellular environment.
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6. Explain the fluid mosaic model proposed by Singer and Nicholson (1972)
Singer and Nicholson (1972) were the first to describe the lipid bilayer with the the fluid
mosaic model. But what does this actually mean? This means is that the individual
phospholipids are not fixed and will move around within the bilayer, much like the
movement of molecules in liquids. One way to imagine this is by thinking of a glass of
water. Whilst the consistency remains constant, the molecules within the glass are free to
move.
The term 'mosaic' refers to the proteins and other molecules found within the membrane that
create a mosaic-iike appearence.
7. What roles the protein channels play in the membranes?
The definition of a channel (or a pore) is that of a protein structure that facilitates the
translocation of molecules or ions across the membrane through the creation of a central
aqueous channel in the protein. This central channel facilitates diffusion in both
directions dependent upon the direction of the concentration gradient. Channel proteins
do not bind or sequester the molecule or ion that is moving through the channel.
Specificity of channels for ions or molecules is a function of the size and charge of the
substance. The flow of molecules through a channel can be regulated by various
mechanisms that result in opening or closing of the passageway.
8. Discuss briefly on the membrane transporters
Transporters are distinguished from channels because they catalyze (mediate) the
movement of ions and molecules by physically binding to and moving the substance
across the membrane. Transporter activity can be measured by the same kinetic
parameters applied to the study of enzyme kinetics. Transporters exhibit specificity for
the molecule being transported as well as show defined kinetics in the transport process.
Transporters can also be affected by both competitive and noncompetitive inhibitors.
Transporters are also known as carriers, permeases, translocators, translocases, and
porters. Mediated transporters are classified based upon the stoichiometry of the
transport process. Uniporters transport a single molecule at a time, symporters
simultaneously transport two different molecules in the same direction, and antiporters
transport two different molecules in opposite directions.
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