ch 4 part 5 reviews Flashcards
Membrane surfaces have a “_____________” that identifies the cell
fingerprint
fingerprint :
The combination of surface proteins and carbohydrates
self marker____________label the body’s cell as friend and are tolerated by the immune system
MHC
___________that immune recognize as foreign molecules :
antigen
our body had ________marker that HIV binds to
CD4
Cholesterol
call ass trol
chole sterol
Helps membranes
Prevent membranes from solidifying at low temperatures.
Hinder phospholipid movement in the moderate temperature
Normal cell function depends on ________________ function
proper cell membrane
Cystic fibrosis is
genetic condition
What holds cells together in a multicellular organism?
CELL-CELL JUNCTIONS
there are primary conncetions between animal cells :
-gap junction
-tight junction
-desmosome
tight junction
form a water-tight seal between cells like
caulking around a tub
desmosomes
act like velcro and fasten cell togather
gap junction
act like a secret passageway and allow material to pass between cells
How do molecules move across membranes?
cell membrane control movement out and in cell by
Selective Permeability
Passive Transport
Active Transport
passive transport
is diffusion or movement of particle (solute) from an area has high concentration to an area has lower concentration
does not require energy
cell membrane are __________
selectivly permable
allow things to pass and not others
from an area has high concentration to an area has lower concentration called
concentration gradient
passive transport method :
-solute like food coloring dropped into solvent such as water
-food-coloring molecules move about randomly and bumping into each other
-the random moton of the molecules end up evenly distributed
There are two types of passive diffusion:
Simple diffusion
Facilitated diffusion
Diffusion of molecules directly through the cell membrane
simple diffusion
Diffusion of molecules across the cell membrane
channel or carrier molecules
Facilitated diffusion
example on faciliated diffusion :
oxygen diffuse left
carbon dioxide diffuse right
