bioliteracy

Movement across the Plasma Membrane : The movement of substances across the plasma membrane:Passive and Active transport

Posted on: February 16, 2011

Passive transport:-

Diffusion

Facillated Diffusion

Osmosis

Diffusion – The movement of ions or molecules from regions of higher concentration to regions of lower concentration.

(Down a concentration  gradient)

Factors influencing the rate of diffusion:-

a)Concentration gradient – Increased rate .

b)Membrane permeability – Increased rate.

c)Increased surface area – Increased rate.

d)Increased molecular weight – Decreased rate.

e)Increased thickness of membrane – Decreased rate.

Osmosis - Osmosis is the movement of water from a region of high water concentration to
                    a region of lower water concentration thought a semi permeable membrane.

Facillated diffusion – Movement of specific molecules across cell membranes through protein channels.

– Similar to simple diffusion but the rate of diffusion is greatly accelerated by the action membrane proteins that act as

carrier molecules and aid in diffusion.

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Active transport :-

Active transport

a)Transport of a substance (protein) across a cell membrane against the concentration gradient.

b)Transport across a cell membrane which requires energy generated by the hydrolysis of some energy carrier (usually ATP).

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2 Responses to "Movement across the Plasma Membrane : The movement of substances across the plasma membrane:Passive and Active transport"

it’s simply nice . ❤

thanks for share the information of movement across the plasma membrane^.^

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