Following is a feature of simple
diffusion?
a) Against a concentration gradient
b) Easy for non-polar substance
c) More in thick membrane
d) Requires carrier protein
Correct Answer - B
Ans. B. Easy for non-polar substance
Simple diffusion:
Refers to diffusion of molecule across the membrane following a
concentration gradient or chemical gradient, but without the help of
any carrier protein.
Factors influencing:
A) Rate of diffusion is directly proportionate :-
Concentration (chemical) gradient
Cross-sectional area of the membrane through which diffusion takes
place
Lipid solubility of the substance
B) Rate of diffusion is inversely proportionate:-
Thickness of diffusion membrane
Size of the particle
Charge or polarity of substance
So, simple diffusion is favored by small size, lipid solubility and
absence of polarity (non-polar substance) and charge (neutral
molecule) through a thin, large membrane where the concentration
gradient is more