Download Dr. Muslim Suardi, MSi., Apt. FACULTY OF

Dr. Muslim Suardi, MSi., Apt.
FACULTY OF PHARMACY
UNIVERSITY OF ANDALAS
Membrane Composition
Membrane Structure
Membrane Type
Phospholipid
(%)
Protein
(%)
General
40
60
Inner mitochondrial
20 -25
75 – 80
Myelin
75
25
Phospholipid
Non polar tail
Polar head
The translocation of a solute from one side of
a biological barrier to the other side in the
intact form.
Passive Diffusion
Facilitated Diffusion
Filtration
Osmosis
Active Transport
Pinocytosis
Passive Diffusion
Passive diffusion on a cell membrane
Fick’s law of
Diffusion
dQ =
dt
DAKp
h
(C1-C2)
dQ =
DAKp
dt
(C1-C2)
h
since D, Kp and h are constant for a given drug membrane and
given that C1>>C2
dQ
dt
= PC1
Facilitated Diffusion
Filtration
Movement of water an solute molecules across the cell membranes
doe to hydrostatic pressure generated by the cardiovascular system.
Osmosis
“The diffusion of water molecule across
a partially permeable membrane”
Effect of Osmosis on Blood cells under different solutions
Facilitated diffusion
Active Transport
Movement again a
concentration gradient
No
Yes
Utilization of energy
No
Yes
Exhibit saturation
Yes
Yes
Riboflavin, Vit B 12
5-FU
Example Substances
The mediated process of moving particles across biological
membrane against the concentration gradient.
Sodium-Potassium pump, an example of Primary active transport
Importance of Active Transport
in Living Systems
Examples of plasma membranes actively transporting
solutes include the following:
1. The absorption of digested food by the walls of
the small intestines of vertebrates.
2. Selective reabsorption in the kidneys of animals
with backbones.
3. The intake of mineral salts from the soil by plant
root hairs.
A process in which a substance or compound gains entry into
a cell without passing though the lipid all membrane
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Shargel, Wu-Pong & Yu, 2004.
Rani & Hiremath, 2000.
Brahmankar & Jaiswal, 2008.
Gibaldi, 1982.