Cytology Flashcards
Cell membrane
Layer of phospholipid that acts as a barrier and surrounds cell
Selectively permeable (chooses what enters/leaves)
Phospholipid
Phosphate molecule (PO4) attached to a long lipid
Phosphate part is polar (can easily mix w/ water)
Lipid part is non-polar (cannot mix w/ water)
Cholesterol
Hold two layers of phospholipids together creating a bilayer
Protein
Scattered along membrane.
Open/close to allow stuff to enter/exit
Membrane transport
Process in which items are moved through membrane
1) passive transport mechanism
2) active transport
Passive transport
Movement occurs w/o use of cellular energy
1) Diffusion
2) osmosis
Diffusion
Net movement of molecules from area of higher concentration to lower concentration
Stops when equilibrium is reached
Osmosis
Net movement of WATER molecules from area of higher concentration of solute to lower concentration of solute
Salt pulls water
Hypertonic
area with higher concentration of salt
Hypotonic
Are with lower concentration of salt
Isotonic
Two areas that have equal levels of salt
Active transport
Cellular energy is used to move big molecules or molecules against concentration gradient
1) Carrier mediated
2) endocytosis
3) exocytosis
Carrier mediated movement
Proteins shuttle molecules across cell membrane
Endocytosis
Cell membrane opens and takes molecules in
Exocytosis
Cell membrane opens and forces molecule out
