Electrical properties and function of membrane ,lipid bilayer and membrane protein

1. Electrical properties and
function of membrane ,Lipid
bilayer and membrane Protein
Presented by :- Prajapati Jinal V .
M.Sc Sem -1
CBO :- 403
Department of life sciences,
H.N.G.U. , Patan

2. Contents
• Electrical properties
• Function of membrane
• Lipid bilayer
• protein

3. Electrical properties
• One of the characteristic features of a living cell
is that is controls the exchange of electrically
charged ions across the cell membrane and
therefore the electrical potential of its interior
relative to the exterior .
• High permeability indicate that particle mass
moves easily through a membrane .
Anions :- Negatively charged particles
Cations :- Positively charged particles

5.  These concentration gradients provide the
potential energy to drive the formation of the
membrane potential .
 Ion transporter /pump protein actively push
ions across the membrane and establish
concentration gradients across the membrane
and ion channels allow ions to move across the
membrane down those concentration gradients .

7.  signals are generated by opening or closing of
ion channels at one point in the membrane ,
producing a local change in the membrane
potential .
 Those ion channels can then open or close as
a result of the potential change , reproducing
the signal .

9. Function of membrane
• Its function is to protect the integrity of the interior
of the cell by allowing certain substances into the
cell , while keeping other substance out .
• Cell membrane also serves to help support the cell
and help maintain its shape membrane is to
regulate cell growth through the balance of
endocytosis and exocytosis .
 several important physiological functions involve
with PM –
1 . Diffusion 2 . Permeability
3 . Semi permeability 4 . Transport across membrane

10. Exocytosis and Endocytosis
 Exocytosis - cellular secretion
 Endocytosis -
• phagocytosis :- “ cell eating “
• Pinocytosis :- “ cell drinking “
• Receptor :- mediated endocytosis , specific
particles , recognition

12. Lipid Bilayer
• The phospholipids of a cell membrane are
arranged in double layer called the lipid
bilayer . The hydrophilic phosphate heads are
always arranged so that they are near water .
• Watery fluids are found both inside a cell
(intracellular fluid) and outside a cell
(extracellular fluid) . The hydrophobic tails of
membrane phospholipids are organized in a
manner that keeps them away from water .

14. Proteins
• Some plasma membrane proteins are located
in the lipid bilayer are called integral proteins
.
 structural proteins :-
• Transport
• Receptors
• Enzymes
• Signal Transducers
• support

17. Reference
• Cell biology , Genetics , Molecular Biology ,
Evolution and Ecology By –
P. S And Agarwal

18. THANK YOU