Biological membranes Flashcards
What is the cell membrane also known as and what is it
-also known as the plasma membrane
-the cell membrane is a semi-permeable area in a cell
that separates the interior components of the cell from the extracellular matrix.
what are the functions of the cell membrane
-Separation between the extracellular fluid and the internal components of the cell.
-Communication with other cells.
-Recognition of external substances.
-Structural support.
-Transport of materials.
why is the plasma membrane described as fluid mosaic model
-mosaic as there are proteins embedded in the membrane
-fluid as phospholipids can move freely in the phospholipid bilayer
what does cholesterol do in the plasma membrane
-makes membranes ridged , maintains fluidity and increases stability of the membrane
how is transport of materials
accomplished
Simple diffusion
facilitated diffusion
osmosis
active transport
co transport
what is a glycoprotein and glycolipid
-glycoprotein is a protein with a carbohydrate attached to it
-glycolipid is a lipid with a carbohydrate attached to it
what is the role of a glycoprotein and glycolipid
- glycoprotein: receptors for chemical signals
-glycolipids: play a role in makers/ antigens
what is the definition of simple diffusion
the net movement of very small molecules from an area of high concentration to an area of low concentration, by simply moving across the phospholipid bilayer
what types of molecules are transported via simple diffusion
small
mostly uncharged
what is facilitated diffusion
the net movement of large or charged molecules from an area of high concentration to low concentration via carrier or channel proteins
what type of molecules are transported via facilitated diffusion
large
charged
what is the definition of active transport
the net movement of molecules from an area of low concentration to high concentration, travelling through a carrier protein. This process also requires energy from the breakdown of ATP
what is the definition of osmosis
the net movement of water particles from an are of high water potential to low water potential, through a partially permeable membrane
what is the main difference between carrier and channel proteins
The main difference between carrier and channel proteins is carrier proteins are not
open readily to both intracellular and extracellular environments, while a channel protein is open to both.
can carrier proteins change shape
yes
