Plasma Membrane Flashcards
LM resolution
.2 microns
EM resolution
2 nanometers
Structures you can see with LM
cells
nucleus
cilia
microvilli (sometimes)
Structures you need EM to see
mitochondria lysosomes perixosomes golgi vesicles cytoskeletal elements plasma membrane
amphipathic
have hydrophobic and hydrophilic properties
cytoplasmic phospholipids
Anionic (PI and PS)
sugar moieties (n-linked glycosylation)
always facing extracellular
scramblases and flippases
proteins that facilitate flipping of phospholipids in cell membrane
disulfide bonds
face extracellular environment
sulfhydryl groups
face cytosol
paroxysmal nocturnal hemoglobinuria (PNH)
defect in bone marrow gene that adds GPI linkages
lack of CD markers on RBCs that are supposed to block complement
causing hemolysis
flow cytometry can be used to identify patients with low CD59 count
Glycocalyx
sugar moieties
recognition via lectins
repulsion due to negative charge
absorption in digestive tract
protection from proteases
lipid raft (caveolae)
Signaling micro-domain: brings receptors and signaling molecules together
lipids and proteins coalescing together
cholesterol and sphingomyelin rich
NA concentration
high outside
low inside
K concentration
low outside
high inside
Ca concentration
high outside
low inside
which polar head groups face inside?
PI
PS
which polar head groups face outside?
PC
PE
What is responsible for ABO blood types?
Glycolipids
factors that control/disrupt membrane fluidity
temp lipid/fatty acids cholesterol cytoskeleton detergents anesthetics hormones
pinocytosis
non-specific ingestions of particles by cell
receptor-mediated endocytosis
allows entry of specific molecules
phagocytosis
cell ingestion of large particles
p-face
side of membrane facing cytosol
e-face
side of membrane facing extracellular space
