The Cell Membrane Flashcards
what is the function of the cell membrane?
- provides protection from the environment (acts as a barrier)
- separates the cell from its surroundings so internal action is seperate from that outside.
- controls the exchange of materials, nutrients and wastes between the cell and it’s environment, so that homeostasis can be achieved.
what is the structure of the membrane like?
a fluid mosaic model:
- fluid: dynamic lateral movement of the biphospholipid layer.
- mosaic: variety of proteins embedded in the layer.
what are the different types of proteins within the cell membrane?
integral: proteins that are embedded in the biphospholipid layer.
peripheral: proteins that are located in the inner or outer surface of the phospholipid bilayer.
what are the components of the biphospholipid bilayer?
polar hydrophilic (water loving) heads.
two non polar hydrophobic (water hating) fatty acid lipid tails, that are placed away from the water.
what are aquaporins?
aquaporins are a unique kind of channel protein for water molecules to move into the cell in a single file during osmosis.
what are channel proteins?
allow large molecules to pass through the membrane, they are constantly open and assist in facilitated diffusion.
what is the role of cholesterol?
stabilities the membrane at high temperatures and allows fluidity at low temperatures.
what is the role of glycolipids and glycoproteins?
maintain the stability of the cell membrane and act as identity markers for communication between cells.
what is the role of enzymes?
speed up the breakdown of chemical messenger molecules such as hormones.
what is the role of receptor proteins?
relay signals between the cell and the extra cellular space
what is the role of transport proteins?
transport hydrophilic solutions or substances across the lipid bilayer. Energy required in the form of ATP.
what is the role of cytoskeleton filaments?
contract and change the shape of the cell.
what is the role of cell adhesion protein molecules (cam)?
stick cells together and allow communication between cells.
