Forces Across Membranes 1 Flashcards
In simple terms, what does the cell membrane do?
Seperates the ECF and the ICF, is responsible for the composition difference between the two
Give an example of some concentration differences between the ECF and the ICF?
Na+ > in ECF
K+ > in ICF
Cl- > in ECF
HCO3- > in ECF
Phosphate/Sulphate > in ICF
Protein > in ICF
How do cell membranes acts as a selective barrier?
Permeable and impermeable to different substances
What substances can freely cross the cell membrane?
O2
Nutrients
CO2
Waste
H2O
What substances cannot cross the cell membrane and the capillary wall?
Ions cannot cross the cell membrane
Plasma proteins cannot cross the capillary wall
Does permeability of the cell membrane change at different times?
Yes
How are membranes dynamic?
They are constantly being formed, changed or dismantled
What forms most of the cell membrane?
Thin layer of phopholipids as a bilayer
Why are membranes flexible?
Fatty acids behave like oil
What could happen to membranes if they are overstretched?
They could rupture
Why are membranes a good insulator against electrical charge?
They prevent the passage of electrons
How to proteins and carbohydrates relate to membranes?
Membranes are embedded with proteins and associated with carbohydrates
Are membrane carbohydrates intra or extra cellular
Extracellular, they are linked to proteins and lipid
What are the carbohydrates of the cell membrane linked to?
Proteins and lipids
What are the carbohydrates of the membrane important for?
Cell-cell communication