Biology Questions and Answers

(Greg DeLong) #1

Biology Questions and Answers


Cell Membrane



  1. What is a membrane?


Membrane is any delicate sheet that


separates onblocking or permitting (se region from anotherelectively or (^)
completely) the passage of substances.
The skin, foconsidered a membrane that ser example, can be (^) parates
the exterior fbody; cellophane, used in chemicalrom the interior of the
laboratories to separate solutions, acts
as a membrane too.



  1. Concerning their
    permeability how are
    membranes classified?


Membranes can be classified as


impermeable, semipermeable or selectivelypermeable, (^)
permeable.
An impermeable membrane is thatthrough which no substance can pass. (^)
Semipermthat let only solveeable membrannts, like water, toes are those
pass through it. Permare those that let solveeable membrannt and solutes,es
like ions and molecules, to pass across
it. There are also selectively pmembranes, i.e., membranes thatermeable
besides allowing the passage of solvent,
let only somwhile blocking ote specific solutes to passhers.



  1. What is diffusion?
    Diffusion is the spreading of substance
    molecules fsubstance isrom a r more conceegion where thentrated to
    another region where it is less
    concentrated. boiling of water in For example, a kitchen during thegaseous
    water particlesin the air by diffusion. tend to uniformly spread

  2. What is meant by
    concentration gradient? Is it
    correct to refer to
    “concentration gradient of
    water”?
    Concentration gradient is the difference
    of concentration otwo regions. f a substance between


Concentrationdesignate the quantity of a solute is a term used to (^)
divided by the total quantity of the
solutiosolvent in this situation it is not n. Since water in general is thecorrect (^)
to refer to “concentration of water” in a
given solution.



  1. What is the difference
    between osmosis and
    diffusion?


Osmosis is the movement of solvent pphenomenon ofarticles (in (^)
general, water) from a region of lower
solute concehigher solute concentration to a rntration. Difegion offusion, (^)
on the other hand, is the movement of
solutes from a region of higher solute
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