logging in or signing up Cell Membrane (Power-point-show) aSGuest19385 Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: Embed: Flash iPad Dynamic Copy Does not support media & animations Automatically changes to Flash or non-Flash embed WordPress Embed Customize Embed URL: Copy Thumbnail: Copy The presentation is successfully added In Your Favorites. Views: 9420 Category: Education License: All Rights Reserved Like it (6) Dislike it (0) Added: May 27, 2009 This Presentation is Public Favorites: 4 Presentation Description No description available. Comments Posting comment... By: anjuvan (25 month(s) ago) Thank you will find ths useful Saving..... Post Reply Close Saving..... Edit Comment Close By: ghimanshug (37 month(s) ago) abhey bekar hai download to hoti nahi hai........ Saving..... 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Cell Membrane Cell membrane Structure : Structure Cell membrane consists of three main components:- - 42% Lipids. - 55% Proteins. - 3% Carbohydrates. 1. LIPIDS:- : 1. LIPIDS:- Lipids consist of:- - Phospholipids. - Glycolipids. - Steroids. Phospholipids are a major component of cell membrane; it is appear as two distinct layers. Hydrophilic head on the outside (Associated with water or charged molecule, because of the presence of phosphate radical). Hydrophobic tails on the inside (Not associated with water nor charged molecule, because of the presence of fatty acids radical). Cholesterol insoluble in water because of the presence of hydroxyl radical. 2. PROTEINS:- : 2. PROTEINS:- Proteins are globular masses floating in the lipid bilayer of cell membrane. It is classified into:- Integral protein:- In which the protein span the width of the membrane entirely one or more times. Peripheral protein:-In which the protein is partially embedded in the membrane phospholipids. 3. CARBOHYDRATES:- : 3. CARBOHYDRATES:- Carbohydrates form complex molecules with proteins and lipids (Glycoproteins and Glycolipids) on the outer surface of the membrane. - Functions of carbohydrates:- 1-Many of carbohydrates are negative charged that give the cell surface its negative charge which repels other negative charge objects. 2-Work as receptors for extra cellular compounds. 3-Some of carbohydrates enter into immune reactions. THE GENERAL FUNCTIONS OF THE CELL MEMBRANE : THE GENERAL FUNCTIONS OF THE CELL MEMBRANE 1.Separate the inside organelles from the external environment. 2.Regulate the entrance and exit of substances. 3.Transfer of information. 4.Establishment of electric potential difference. 5.Site of biological activities. 6.Attachment between cells. 7.Removal of wastes. The transporting of materials through the cell membrane : The transporting of materials through the cell membrane Cell membrane work as a gate keeper for the entrance and exit substances, As some substances pass from cell membrane easily, others pass more difficult, and others can't pass through cell membrane, this selective passage (selective permeability) because of the conditions outside the cell are different from inside. outside cell inside cell sugar H2O salt NH3 lipid The transporting of materials through the cell membrane : The transporting of materials through the cell membrane If substances move from high concentration to low concentration that's called passive transport, but if the substances move from low concentration to high concentration required energy for transporting this process called active transport, also substances can enter and exit the cell by endocyosis and exocytosis. From the previous we can know that; there are three ways for transporting of substances through the cell membrane:- 1.Passive transport. 2.Active transport. 3.Exocytosis and endocyosis. 1. PASSIVE TRANSPORT:- : 1. PASSIVE TRANSPORT:- I-Diffusion:- 1. PASSIVE TRANSPORT:- : 1. PASSIVE TRANSPORT:- II-Osmosis:- 2. ACTIVE TRANSPORT:- : 2. ACTIVE TRANSPORT:- The most active transport mechanism in the body is the transport of sodium ions out of the cell and at the same time pump the potassium ions to the inside, this mechanism is called sodium-potassium pump, this pump is responsible for maintain the sodium and potassium concentrations inside cell. -Functions of the sodium-potassium pump:- 1.It has three receptor sites for binding sodium ions on the portion of the protein that move to the interior of the cell. 2.It has two receptor sites for potassium ions on the outside. 3.The inside portion of this protein adjacent to or near to the sodium binding sites has ATP activity. Summary the cell membrane transport mechanism : Summary the cell membrane transport mechanism High concentration Low concentration High concentration High concentration Low concentration Low concentration lipid bilayer opining Protein carrier sodium-potassium pump Simple diffusion Facilitated diffusion Active transport ATP 3. EXOCYTOSIS AND ENDOCYTOSIS:- : 3. EXOCYTOSIS AND ENDOCYTOSIS:- Thank you for your attention : Thank you for your attention References Essentials of anatomy & physiology Pro:-Martini / Bartholomew P: 61, 62 Integral principles of zoology Pro:- P: 46:50 Working team Essam Mohammed Mahmoud Badawe Mahmoud Kamal Mohammed Dif Mohsen Tolba Best wishes 3sam Mo7amed Websites http://en.wikipedia.org/wiki/cell membrane You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.