The Fluid Mosaic Model of Membranes Flashcards
intracellular membranes form compartments within the cell such as the …………..
nucleus, mitochondria and RER
What do membranes do
The cell surface membrane creates an enclosed space separating the internal cell environment from the external environment,
control the exchange of material across them, as well as acting as an interface for communication
Membranes are partially permeable(allows smaller solutes or water molecules
Substances can cross membranes by diffusion, osmosis and active transport
What does partially permeable mean
(allows smaller solutes or water molecules
The fluid mosaic model also helps to explain
membranes(7nm)
Passive and active movement between cells and their surroundings
Cell-to-cell interactions
Cell signalling
Phospholipids structurally contain two distinct regions:
a polar head and two nonpolar tails
The phosphate head of a phospholipid is polar (hydrophilic) and therefore
soluble in water
The lipid tail is non-polar (hydrophobic) and therefore
insoluble in water
If phospholipids are spread over the surface of water they form a single layer with the hydrophilic phosphate heads …… the water and the hydrophobic fatty acid tails ………from the water
This is called a phospholipid ………….
the hydrophilic phosphate heads in the water and
the hydrophobic fatty acid tails sticking up away from the water
This is called a phospholipid monolayer
If phospholipids are mixed/shaken with water they form…….. with the hydrophilic phosphate heads facing ……. towards the water and the hydrophobic fatty acid tails facing……………..
This is called a ………
spheres
out
in towards each other
micelle
Alternatively, two-layered structures may form in sheets
These are called …………. – this is the basic structure of the cell membrane
phospholipid bilayers
