cell size, surface area and volume formulas Flashcards
what does cellular metabolism depend on?
cell size
what exits the cell and how?
cellular waste must leave
dissipate thermal energy
what enters the cell?
nutrients and other resources/chemical materials
a high surface area-to-volume ratio of a cell does what?
optimizes the exchange of material through the plasma membrane
SA formula for spherical cells
4pir^2
V formula for spherical cells
(4/3)pir^3
SA:V ratio formula for spherical cells
SA/V
SA formula for cuboidal cells
6S^2
V formula for cuboidal cells
S^3
SA:V ratio for cuboidal cells
SA/V
problems with larger cells having a lower SA:V ratio
lose efficiency exchanging materials
cellular demand for resources increases
rate of heat exchange decreases
plasma membrane function
separates internal cell environment from external environment
what does it mean to say phospholipids are amphipathic?
hydrophilic head and hydrophobic tails
forms a bilayer
selective permeability
the ability of membranes to regulate the substances that enter and exit
FLUID mosaic model
membrane is held together by weak hydrophobic interactions and can therefore move and shift
temp affects fluidity
unsaturated hydrocarbon tails help maintain fluidity at low temps; kinked tails prevent tight packing of phospholipids
