1 / 11

Cell Membrane Structure

Cell Membrane Structure. Phospholipid bilayer: a double layer of lipids makes up most of the cell membrane. Proteins: many proteins are embedded in the phospholipid bilayer Some act as channels to transport materials through the membrane

presley
Download Presentation

Cell Membrane Structure

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Cell Membrane Structure

  2. Phospholipid bilayer: • a double layer of lipids makes up most of the cell membrane. • Proteins: many proteins are embedded in the phospholipid bilayer • Some act as channels to transport materials through the membrane • Some are connected to carbohydrate chains on the exterior of the cell • Carbohydrates: • Short chains of carbohydrates are connected to proteins or lipids on the exterior surface of the cell • They act as markers to identify the cell

  3. Selectively Permeable • Cell membranes act as barriers, controlling which materials enter and leave the cell • Materials can enter or leave the cell based on their size and the amount of substance present(concentration)

  4. Cell Transport PassiveTransport:small molecules can cross over the cell membrane without using extra energy Diffusion:small particles flow down a con- centration gradient from an area of high [concentration] to an area of [low] Osmosis:the diffusion of water molecules over the cell membrane Facilitated Diffusion: particles still travel from [high] to [low], but they pass through channels in the membrane Example: ions • Raw Egg Osmosis Demonstration

  5. Types of Solutions and Movement of Water Hypertonic Solutions • Hypertonic solutions have a HIGHER concentration of solutes than what is inside the cell • This causes water to move OUT of the cell. • Hypertonic environments shrink animal cells.

  6. Hypotonic Solution • Hypotonic solutions have a LOWER concentration of solutes than what is inside the cell • This causes water to move INTO the cell. • Hypotonic environments swell animal cells.

  7. Isotonic Solutions • Isotonic solutions have THE SAME concen- trationof solutes as what is inside the cell • While water will move in and out, there is no NET movement of molecules. • Isotonic environments cause no net change.

  8. Active Transport Active Transport requires additional energy, because substances are being transported AGAINST the concen- tration gradient(from [low]  [high]) Endocytosis: endo: within cyt: cell -osis: process of the process of taking materials into a cell by forming vesicles around the substance pinocytosis:pin: to drink cells taking in substances dissolved in water phagocytosis:phag: to eat cells taking in large particles Exocytosis: exo- from outside the process of removing substances from the cell by fusing internal vesicles with the cell membrane

  9. White Blood Cell Engulfing Bacteria

More Related