The Cell Membrane Flashcards
Is the cell membrane rigid or fluid?
fluid
purpose of cell membrane?
take in food, remove waste, let specific molecules in and out, communicate with other cells, gather information, repair itself
what two things are the cell membrane made of?
proteins+phospholipids
what does phospholipid bilayer mean?
two layers of phospholipids
the cell membrane is semi/selectively permeable, meaning _____
it only lets some materials in and out
what is the fluid mosaic model of the cell membrane?
model that suggests the cell membrane is moving and has proteins embedded within
what are the two components phospholipids are composed off?
head- hydrophilic (likes water) faces outwards
tail- hydrophobic (hates water)
faces inwards
what do integral proteins do?
allow movement of large molecules and ions through protein integral channels
what do peripheral proteins do?
carry signals and relay it to other parts of the membrane
what does cholestrol do in the cell membrane?
helps retain fluidity
- prevents compaction at low temps
- prevents expansion at high temps
what do carbs do in the cell membrane?
‘name tags’ of the cell
play a role in cell recognition
what are glycoproteins?
proteins that have carbs attached
cell recognition, cell adhesion, immune response
e.g hormones, enzymes
what are glycolipids?
lipids with carbs attached
cell recognition. signalling, stability
what are microtubules?
attached to inner membrane
anchor to cytoskeleton
what are the 5 main categories of molecules that can pass through the cell membrane
small, polar
small, non-polar
large, polar
large, non-polar
ions
one way of distinguishing molecules that can pass through the cell membrane is how they react to _____
water
small, non-polar molecules (O2. CO2)
can this pass through the cell membrane? why/why not
small, can squeeze through, don’t need proteins and can diffuse quickly
small, non- polar molecules (O2, C)2)
can this pass through the cell membrane? why/why not
small, can go through without help quite easily
large non-polar molecules (carbon-rings
can this pass through the cell membrane? why/why not
yes, can pass through but it is a slow process
large, polar molecules (small sugars- glucose) can this pass through the cell membrane? why/why not
no, too large and charge doesn’t let it pass through without help of proteins
ions (Na+ ion)
can this pass through the cell membrane? why/why not
charge doesn’t let it pass without help of protein
