Cell membrane Flashcards
(13 cards)
What is an open system?
Exchange matter and energy with their surroundings
What 7 things do cells do?
Intake nutrients, movement, growth, respond to stimuli, exchange gases, waste removal, reproduction.
What is the cell membrane’s role?
Separates the intracellular environment from the extracellular environment, semi-permeable, moves nutrients, gases and wastes, maintain’s the equilibrium within the cell.
Cell membrane- double layer
Phospholipid bilayer, proteins are suspended in the bilayer, sugar molecules are attached to some of the proteins
Fluid mosiac model - Cell membrane
Membrane proteins are interspersed through the membrane, with their hydropilic and hydrophobic ends.
What does a Biological barrier do?
Prevents many substances from entering cells. Most organelles are also surrpunded by membranes.
Selective filter
Semi-permeable - only some particles can move in and out of the cell.
What is the phosolipid bilayer?
2 layers of phospholipids with embedded proteins.
What does each layer have in the phospholipid bilayer?
A hydrophilic phosphate end and a hydrophobic lipid tail.
Integral proteins
Span the bi-layer act as channels for materials to enter and exit the cell.
Peripheral proteins
Act as markers for cellular recognition and communication.
Fluid mosaic model
Cell membranes are constantly moving and changing, gives cell flexibility, changes the position of proteins.
What are the 3 functions of the cell membrane?
Barrier (keeps wastes, toxins out), organization (membranes surround and package materials in vesicles), selective filter (semi permeable, allows certain substances in or out)
