MOLECULAR STRUCTURE OF BIOLOGICAL MEMBRANES INCLUDING VARIOUS TYPES OF CHANNELS AND TRANSPORTERS..

1. a
Presentation
on
molecular structure of biological membranes including various types of channels
BABAsaheb BHIMRAO AMBEDKAR UNIVERSITY,LUCKNOW
SUBMITTED BY, SUBMITTED TO,
AZAD SINGH Dr. SUDIPTA SAHA
M.PHARM(SEM.ii) ASSIST.PROFESSOR

2. CONTENTS
INTRODUCTION
TYPS OF TRANSPORT MECHANISM
i)-PASSIVE TRANSPORT MECHANISM
ii)-ACTIVE TRANSPORT MECHANISM
MEMBRANE TRANSPORTER AND SIGNIFICANCE
REFRENCES

13. DIFFUSION
Diffusion is the net passive movement of particles (atoms, ions
or molecules) from a region in which they are in higher
concentration to regions of lower concentration. It continues
until the concentration of substances is uniform throughout.
EXAMPLE-
Gas exchange for photosynthesis — carbon dioxide from air to leaf, oxygen from leaf to air.
• Gas exchange for respiration — oxygen from blood to tissue cells, carbon dioxide in opposite
direction.
• Transfer of transmitter substance — acetylcholine from presynaptic to postsynaptic membrane
at a synapse.
• Osmosis — diffusion of water through a semipermeable membrane.

14. Osmosis
It is the diffusion of water through a
partially permeable membrane from a more dilute
solution to a more concentrated solution – down
the
water potential gradient)
Note: diffusion and osmosis are both passive, i.e.
energy from ATP is not used. A partially permeable
membrane is a barrier that permits the passage of
some substances but not others; it allows the
passage of the solvent molecules but not some of
the larger solute molecules.
EXAMPLE-
Re-absorption of water by the proximal and distal
convoluted tubules of the nephron.

15. Facilitated Diffusion
Facilitated diffusion is based on transporters
that must specifically bind the
substance to be transported.
The binding causes a
conformation change,
which allows the transported
substance to be released on the other
side of the membrane.

22. GATEDION CHANNELS

25. TEMPERATURE-GATED
Found in sensory neurons in the skin
and mucous membranes and open/close
with temperature changes.
Naturally, leads to sensations of warm
and cold

26. ION PAIR TRANSPORT
EXAMPLE-
Propranolol a basic drug
that forms an ion pair with
oleic acid is absorbed by
this mechanism

27. What is active transport?
Active transport is the transport of
substances from a region of lower
concentration to higher concentration
using energy, usually in the form of
ATP.
Examples: Na, K and Ca active
transport.
1.sodium-potassium pump
2.Calcium pump
3.Potassium hydrogen pump

28. Pumps involvedin ACTIVE TRANSPORT
1.Sodium-potassium pump
Found in many cells
2.Calcium pump
Found in membrane of
Sarcoplasmic reticulum
3.Potassium hydrogen pump
Found in Gastro intestine
cell membrane

29. Secondary active transport
The transport of substances against a concentration
gradient involving energy to establish a gradient across the
cell membrane, utilizes the gradient to transport a molecule
of interest up its concentration gradient .
THE TRANSPORT MAY BE
In the same direction (SYMPORT)
In the opposite direction (ANTIPORT)

31. Symport (Co-transport)
Transport of two substances using the
energy produced by concentration
difference developed by primary active
transport
Substances are moving in the same
direction.
Example: transport of amino acids,
Glucose.

32. Mechanism of Co-transport
ECF
ICF
ECF
ICF
ECF
ICF
sodium
glucose

33. Antiport (Counter-transport)
 In this process, the two substances move
across the membrane in opposite
directions.
 Example:
Exchange of H+ and Na+ in Renal
tubule.

34. The Na+, glucose Secondary Transport
 Sodium co-transport
of glucose occurs
during absorption of
glucose from the
intestine and
reabsorption of
glucose from renal
tubule.

35. MEMBRANE TRANSPORTS AND THEIR SIGNIFICANCE
ENDOCYTOSIS
EXOCYTOSIS

38. Exocytosis is used for the following purposes:
 Release enzymes, hormones, proteins, and glucose to be used
in other parts of the body.
 Neurotransmitters (in the case of neurons).
 Communicate defense measures against a disease.
 Expel cellular waste.
Endocytosis is usedfor the following purposes:
 Receive nutrients.
 Entry of pathogens.
 Cell migration and adhesion.
 Signal receptors.

39. PHAGOCYTOSIS
PINOCYTOSIS
ENDOCYTOSIS INCLUDES TWO TYPES OF PROCESS

40. PHAGOCYTOSIS
Phagocytosis is the process by
which living cells called
phagocytes envelop or engulf
other cells or particles.
and this process called cell
eating.

42. PINOCYTOSIS
In pinocytosis or cell drinking
the cell engulfs extracellular
fluid including molecules such
as sugars and proteins.
And when liquid instead of a
solid.

44. Example-Orally administered sabin
polio vaccine , large protein molecules
and toxin are absorbed by the
pinocytosis

45. REFERNCES
RANG AND DALE’S “PHARMACOLOGY” 7 EDITION PUBLISHED BY
ELSEVIOUR,PAGE NO-92-95.
BRAHMANKAR D.M.,B.JAISWAL SUNIL “3 EDITION 2015 PUBLISHED
BY VALLABH PRAKASHAN,PAGE NO-10-18.
Singer, S. J., and Nicolson, G.L. 1972. The fluid mosaic model of the structure
of cell membranes. Science PAGE NO-175, 720-731
Palmgren, Michael G. (2001-01-01). "PLANT PLASMA MEMBRANE H+-
ATPases: Powerhouses for Nutrient Uptake". Annual Review of Plant
Physiology and Plant Molecular Biology. 52 (1): 817–845.

46. Thank
You