TRANSCELLULAR, VESICELLULAR, PARACELLULAR

1. MEMBRANE
TRANSPORT MECHANISMS
PREPARED BY :
PHARM-D 4TH
YEAR

2. PREPARED BY
JAVERIA SIDDIQUI

3. CELL MEMBRANE
 Semi permeable membrane.
 Maintain homeostasis
 Protection and support for the cell.

4. STRUCTURE OF CELL
MEMBRANE
 Double layer of phospholipid.
 Elastic(7.5-10nm)
 Contains proteins called membrane proteins
 Selective permeable
LIPID BILAYER:
2 layers of phospholipids
 Phosphate head is polar (water loving)
 Fatty acid tails non-polar (water fearing)

5. CELL MEMBRANE
PROTEINS
 Integral Proteins
 Channel Proteins
 Carrier Proteins
 Enzyme Proteins
 Receptor Proteins

6. FUNCTIONS OF CELL
MEMBRANE
 Protective function
 Selective permeability
 Absorptive function
 Excretory function
 Maintenance of shape and size of cell

7. TRANSPORT-What it
means?
 Its highly selective filter, permits nutrients leaves the waste products from the
cell.
 Maintain Homeostasis
 Play an important role in cell to cell communication
 It detects Chemical messengers arriving at the cell surface.

8. TRANSPORT MECHANISMS
 Active transport
 Passive transport

9. PREPARED BY
MAHA KIRAN

10. TYPES OF TRANSPORT
MECHANISMS
 Transcellular
 Vesicellular
 Paracellular

11. ACTIVE TRANSPORT
 The process needs energy (ATP) for transportation of drug molecules
 Molecule moves into the cell against its concentration gradient in the lipid
bi-layer membrane
 Transport small particle ions through the membrane i.e. glucose,
aminoacids, organic acids and inorganic ions (SO4–, PO4–, K+ etc).
 Ions movement  directly depend on ATP
 Ions movement does not directly require ATP; energy coupled process

12. PRIMARY ACTIVE
TRANSPORT
In primary active transport,
hydrolysis of energy rich
molecules such as ATP provide
energy required for transport of
molecules form lower
concentration to higher
concentration across membrane.

13. SECONDARY
ACTIVE TRANSPORT
 In secondary active transport, one type of molecule migrates
from higher concentration to lower concentration, releasing
energy.
 This released energy is used to transport other molecule from
its lower concentration to higher concentration across cell
membrane
 Further categorized into three types:
 Uniport : Moves only one kind of molecule in same direction
 Symport : Moves different kind of molecule in same direction
 Anti port :Moves molecule in opposite direction

15. PREPARED BY
MAHAM FAYAZ

16. PASSIVE TRANSPORT
A process that does not require energy to move molecules from a HIGH to
LOW concentration
 Diffusion
 Facilitated Diffusion
 Osmosis

17. DIFFUSION
Diffusion is the movement of small
particles across a selectively
permeable membrane like the cell
membrane until equilibrium is
reached.
 These particles move from an area
of high concentration to an area of
low concentration.
outside of cell
inside of cell

19. PREPARED BY
MARIA AKRAM

20. ION PAIR TRANSPORT
Drugs which are ionized undr all pH conditions are transported through Ion-Pair
transport mechanism.
Example:
 Quateranary Ammonium compound
 Sulphonic acids
Ion pair transport is a passive transport mechanism in which the drug forms a reversible
neutral complex with endogenous ion of the GIT, passively diffused through the
membrane and reaches systemic circulations.
Example:
 Propanolol is a basic drug that forms a ion pair with oleic acid and absorbed
through GIT.

22.  Facilitated diffusion is a type of passive transport
that allows substances to cross membranes with
the assistance of special transport proteins. Some
molecules and ions such as glucose, sodium ions,
and chloride ions are unable to pass through
the phospholipid bilayer of cell membranes.
 Through the use of ion channel proteins and
carrier proteins that are embedded in the cell
membrane,​ these substances can be transported
into the cell.

23. FACILITATE DIFFUSION

24. PREPARED BY
HAREEM KHALID

25.  A vesicular transport protein, is a membrane protein that regulates or facilitates the
movement of specific molecules across a vesicle's membrane
 Material move in or out of cell by mean of vesicles Also known as Bulk transport
 Vesicular Transport Includes:
Endocytosis
 It is a type of active transport that moves particles, such as large molecules, parts of
cells, and even whole cells, into a cell. Three Types of Endocytosis includes:
 1.Phagocytosis
 2.Pinocytosis
 3.Recepter mediated endocytosis

26.  Ingestion of a smaller cell or cell fragment, a
microorganism, or foreign particles by means
of the local infolding of a cell's membrane

27. Condt…
Process by which liquid droplets are
ingested by living cells. Pinocytosis
is one type of endocytosis, the
general process by which cells
engulf external substances
Also called clathrin-mediated endocytosis,
is a process by which cells absorb
metabolites, hormones, other proteins –
and in some cases viruses The specificity
results from a receptor-ligand interaction.

28. Cell transports secretory products
through the cytoplasm to the plasma
membrane.
Exocytosis occurs when a cell
produces substances for export, such as
a protein, or when the cell is getting rid
of a waste product or a toxin.

29. PREPARED BY
MAHAM UROOJ

30. PARACELLULAR PATHWAY
 It involves the aqueous route of
transport.
 It refers to the transfer of drug by
passing through the intracellular spaces
between the cells.
 The cells are joined together via closely
fitted junction on other apical side.
 In general, absorptive epithelia, such as
that of small intestine tend be leakier
than other epithelia.

31.  Lipophilicity of drug isn't needed.
 Avoids drug degradation because of living thing
catalyst activity.

32.  Transport of drug through the pores of biological
membrane.
 The drug molecules dissolve in the aqueous medium at
the site of absorption and move along with the solvent
through the aqueous pores.
 Examples of drug that use Paracellular transport is
cimetidine, atenolol .urea , water , sugar .