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Cell Membranes
Created @February 12, 2025 4:49 PM
Class Cells to Systems
Cell Membranes
Surrounds cells
Acts as barrier between cell and environment
Partially permeable- Controls what substances exit and enter the cell
Fluid Mosaic Structure
Describes molecule arrangement in membrane
Phospholipids form bilayer which constantly moves
Bilayer contains cholesterol molecules and proteins scattered in the layer
Receptor proteins on membrane surface detects chemical release
Certain proteins have polysaccharide chain attached to it, making it a
glycoprotein
Phospholipids
Contains head and tail, head being hydrophilic and tail is hydrophobic
Molecules arrange into bilayer
Centre of layer is hydrophobic
Side of the membrane is hydrophilic
Cell Membranes 1
, Cholesterol
Type of lipid
In all cell membranes
Fits between phospholipids
Restricts phospholipid movement making structure more rigid
Maintains animal cell shape
Temperature Increases Membrane Permeability
Temp below 0 Degrees
Causes channel and carrier proteins to deform
Temp Between 0 and 45 degrees
Phospholipids have slight movement
Tightly packed together
Makes membrane partially permeable
Temp increase means phospholipids are more energetic
Increases permeability of membrane
Temp Above 45 degrees
Phospholipid melts increasing membrane’s permeability
Due to water expansion inside cell, water pressure increases
Channel and carrier proteins deform
Diffusion
Net movement of particles from high concentration to lower concentration
Cell Membranes 2
Cell Membranes
Created @February 12, 2025 4:49 PM
Class Cells to Systems
Cell Membranes
Surrounds cells
Acts as barrier between cell and environment
Partially permeable- Controls what substances exit and enter the cell
Fluid Mosaic Structure
Describes molecule arrangement in membrane
Phospholipids form bilayer which constantly moves
Bilayer contains cholesterol molecules and proteins scattered in the layer
Receptor proteins on membrane surface detects chemical release
Certain proteins have polysaccharide chain attached to it, making it a
glycoprotein
Phospholipids
Contains head and tail, head being hydrophilic and tail is hydrophobic
Molecules arrange into bilayer
Centre of layer is hydrophobic
Side of the membrane is hydrophilic
Cell Membranes 1
, Cholesterol
Type of lipid
In all cell membranes
Fits between phospholipids
Restricts phospholipid movement making structure more rigid
Maintains animal cell shape
Temperature Increases Membrane Permeability
Temp below 0 Degrees
Causes channel and carrier proteins to deform
Temp Between 0 and 45 degrees
Phospholipids have slight movement
Tightly packed together
Makes membrane partially permeable
Temp increase means phospholipids are more energetic
Increases permeability of membrane
Temp Above 45 degrees
Phospholipid melts increasing membrane’s permeability
Due to water expansion inside cell, water pressure increases
Channel and carrier proteins deform
Diffusion
Net movement of particles from high concentration to lower concentration
Cell Membranes 2
