diffusion across membranes Flashcards
1
Q
what is facilitated diffusion?
A
the movement of molecules from an area of high to low concentrations via protein channels or carriers not involving ATP
2
Q
when not using the cells metabolic energy what forms of energy do substances passing though the membrane use?
A
kinetic energy
3
Q
what molecules can diffuse through the bilayer
A
fat soluble molecules such as steroid hormones
because they dissolve in the lipid bilayer
4
Q
why does water diffuse through a protein channel?
A
because it is polar and insoluble in lipid
5
Q
factors that affect rage of diffusion
A
temperature diffusion distance surface area size of diffusing molecule concentration gradient
6
Q
comment on the specificity of carrier proteins
A
there are specific carrier proteins for different types of molecules
