1. Active and vesicular Transport
By Dr Nazish

2. A four-year-old boy severely dehydrated child presented with one day history of severe diarrhea and vomiting and a temperature up to 40°C (104°F). Over the previous 12 hours the child had watery, bowel movements every Minutes . Mother gave the history that vommitting is now settled but diarrhea is still there On physical examination, the patient's temperature was 39.6°C , his respiratory rate was 28 and his pulse rate was The patient weighed 15 kg (33 lb) and had a blood pressure measurement of 90/60 mm Hg. He was alert but irritable, with a dry mouth . Bowel sounds were increased, and the abdominal examination was otherwise normal. The child was admitted to the peadriatic OPD and was given an intravenous antibiotic as well as intravenous saline Condition of the child improved and was discharged in the morning. Along with an oral antibiotic cover for 5 days the doctor also advised that the child should be continued with ORS for atleast 2 days.

3. Active transport
It is the movement of the molecules against the electrical, concentration or the pressure gradient with the use of energy.

4. Active transport is a type of assisted transport.
A substance moves against its concentration gradient.
It requires a carrier molecule.
Primary active transport requires the direct use of ATP to drive a sodium-potassium pump.
Secondary active transport is driven by a concentration gradient of ions established by primary active transport.

5. PRIMARY ACTIVE TRANSPORT

6. Figure 3.29 Page 92 ECF Na+–K+ pump (Passive) (Active) Na+ channel
K+ channel
(Passive)
(Active)
ICF
Figure Page 92

7. side and drops off K+ on its high-concentration side
When open to the ECF, the carrier drops off Na+ on its high-concentration
side and picks up K+ from its low-concentration side
Figure Page 82
ECF
ICF
When open to the ICF, the carrier picks up Na+ from its low-concentration
side and drops off K+ on its high-concentration side
Phosphorylated conformation Y
of Na+–K+ pump has high affinity
for Na+ and low affinity for K+
when exposed to ICF
Dephosphorylated
conformation X of Na+–K+
pump has high affinity for
K+ and low affinity for Na+
when exposed to ECF
= Sodium (Na+)
= Potassium (K+)
= Phosphate

8. Importance of Na+-K+ Pump
Establish Na+-K+ concentration gradient across membrane  generation of membrane potential.
Regulate cell volume by controlling concentration of solutes inside the cells
Pump energy is used indirectly for co- transport of other materials, i.e., glucose, amino acids

9. What would be the effect on cell volume, if the sodium pottasium pump is damaged?

10. SECONDARY ACTIVE TRANSPORT

12. Secondary active transport
Energy is required in the entire process but not directly
Transportation against conc gradient
Using carrier with more than one binding site

13. Figure 3.23 Page 84 Cotransport carrier Luminal border Lumen of
intestine
No energy
required
Figure Page 84
Tight
junction
Energy
required
Epithelial cell lining
small intestine
Na+–K+ pump
No energy
required
Glucose
carrier
Basolateral
border
Blood vessel
= Sodium
= Potassium
= Glucose
= Phosphate

14. Sodium glucose co transport in intestinal and renal cells

16. COUNTER TRANSPORT SODIUM HYDROGEN COUNTER TRANSPORT
SODIUM CALCIUM COUNTER TRANSPORT

17. Think and link

18. A four-year-old boy severely dehydrated child presented with one day history of severe diarrhea and vomiting and a temperature up to 40°C (104°F). Over the previous 12 hours the child had watery, bowel movements every Minutes . Mother gave the history that vommitting is now settled but diarrhea is still there On physical examination, the patient's temperature was 39.6°C , his respiratory rate was 28 and his pulse rate was The patient weighed 15 kg (33 lb) and had a blood pressure measurement of 90/60 mm Hg. He was alert but irritable, with a dry mouth . Bowel sounds were increased, and the abdominal examination was otherwise normal. The child was admitted to the peadriatic OPD and was given an intravenous antibiotic as well as intravenous saline Condition of the child improved and was discharged in the morning. Along with an oral antibiotic cover for 5 days the doctor also advised that the child should be continued with ORS for atleast 2 days.
What would be the effects on tonicity of the body fluids of this child?
Explain the effects of change of tonicity on the size and shape of body cells.
What type of IV fluid is given to the child and why? How does ORS therapy works? Explain the physiological basis of mechanism of action of ORS in treatment of dehydration..

19. VESICULAR TRANSPORT

20. Other kinds of assisted transport are:
Vesicular transport - Materials move in or out of the cell wrapped in a membrane.
Need energy
Examples of vesicular transport are endocytosis and exocytosis.
By endocytosis substances move into the cell.
Exocytosis is the reverse process.

21. Receptor-mediated endocytosis
Particular
protein
Surface
receptor site
Endocytotic
pouch
Endocytotic
vesicle
Nucleus
of cell
Receptor-mediated endocytosis

22. Phagocytosis Bacterium Pseudopod Phagocytic vesicle White blood cell
Lysosome
Phagocytosis

23. Click to view animation.
Phagocytosis
Click to view animation.

24. Click to view animation.
Secretion
Click to view animation.

25. Exocytosis

26. Characteristics of methods of membrane transport: DIFFUSION
Method of transport
Substances involved
Energy requirements & force producing movements
Limits to transport
Through lipid bilayer
Nonpolar molecules of any size
O2, CO2, FA
Passive
Continues until gradient is abolished
Through protein
Specific small ions, Na,K,Cl
Passive
Until Steady state reached
Special case of osmosis
Water only
Passive
Until Steady state, or stopped by opposing hydrostatic pressure, or cell dies

27. Characteristics of methods of membrane transport: CARRIER MEDIATED TRANSPORT
Method of transport
Substances involved
Energy requirements & force producing movements
Limits to transport
Facilitated DIFFUSION
Specific polar molecules
glucose
Passive
Displays a Transport maximum (Tm). Saturation
PRIMARY ACTIVE TRANSPORT
Specific small ions, Na,K,Cl
Active
Transport maximum. Saturation
Secondary ACTIVE TRANSPORT
Specific polar molecules and ions for which cotransport carriers available
Active
Transport maximum Cotransport carrier saturation

28. Characteristics of methods of membrane transport: VESICULAR TRANSPORT
Method of transport
Substances involved
Energy requirements & force producing movements
Limits to transport
ENDOCYTOSI S
Pinocytosis
Small volume of ECF may be bound with proteins
ATP required
Control poorly understood
Phagocytosis
Multimolecular particles
ATP required
Active
Necessitates binding to specific receptor site
EXOCYTOSIS
Secretory products Large molecules passing through Membrane recycling
ATP required Increase in cytosolic Ca induces fusion
Secretion triggered by neural or hormonal stimuli

29. Thank You
and
Keep Smiling