Unit-II Molecular Transport in Living Cells 1st Semester By Elite Nursing Platform.pdf

Communication skills

1. Molecular
Transportin living
Cells

2. PresentedBy
•ELITE NURSING PLATFORM

3. Topic Outlines
•Transport in living cells
•Diffusion
•Random Motion and Diffusion Equation
•Osmosis and osmotic pressure
•Diffusion across Membrane
•Membrane Potential

4. Why transport
occurs?
Cellular transport occurs to
maintain the cellular homeostasis
and cellular gradient.

5. Transportin living cell
Cell transport
Passive
Diffusion
Osmosis
Facilitated
diffusion
Active
Channels Vesicles
Exocytosis
Endocytosis
Phagocytosi
s
Pinocytosis

6. Transportin Cell
Active transport Passive transport
•Involves the Movement of molecules
from the area of low concentration to
high concentration gradient.
•It involves the movement of molecules
from the area of high concentration to
the area of low concentration.
•Requires energy in the form of ATP.•No energy needed.
•It is the rapid movements of
Molecules.
•It is the Slow movement.
•Movement of large molecules occurs
by the Active Transport
•Only small molecules or liquid
molecules transferred passively.

7. Diffusion
•Movement of gas Molecules from the area of High concentration to
the area of low concentration.
•Sometimes termed as Facilitated diffusion in which gaseous
molecules move across the membrane.
•No use of ATPs.

8. Examplesof diffusion
•Examples of diffusion in living cells are:
•Gaseous exchange in respiration
•Nutrients Uptake By cell
•Waste production and elimination
•Ionic Balance

10. Diffusion across Membrane

11. RandomMotion
•Random Motion in living cells refers to the spontaneous and
unpredictable movements of the cellular components and molecules
within the cells.
•It is the fundamental aspect of cellular physiology and play important role
in various cellular processes.
•It includes:
Brownian Motion Molecular Interactions
Intracellular Transport Cellular Dynamics
Diffusion

12. RandomMotion
•Brownian Motion: Brownian motion refers to the random movement of
the particles suspended in a fluid medium.
•Brownian Motion is more pronounced in terms for smaller particles. As
particles become smaller, the impact of thermal energy from surrounding
become more significant.
•Temperaturehas also the effect on Brownian motion. High temperature
lead to greater kinetic energy in the surrounding leading to more vigorous
Brownian motion.

13. Diffusion Equation
•The diffusion equation tells us how the molecules transport in the cell
and out of the cells.
•This equation shows that “the rate of diffusion is inversely
proportion to the square root of its molar mass”

14. Continue…
•Lighter Molecules Diffuses faster as compared to the Havier ones.
•It has been experimentally verified through various studies
including diffusion of gas.
•It has the application in chemistry, physics, and the environmental
sciences etc.

15. Osmosis
•“The spontaneous passage, movement, or diffusion of water or other solvent
through the semipermeable membrane called osmosis.”
•Solvents moves from the high concentration gradient to low concentration
gradient.
•It is essential for maintaining cellular structure, turgor pressure, and their
function.
•Essential for Osmoregulation. Process by which organismic cell control the
concentration of solute and solvent.

16. Osmotic
pressure
Osmotic pressure in living cells

17. OsmoticPressure
•Osmotic pressure is the pressure exerted by the solvent as
it moves through the semipermeable membrane to equalize
the concentration of solute and solvent.
•In osmotic pressure we deals with:
•Hypotonic
•Hypertonic
•Isotonic

18. Hypertonic pressure
Hypertonic pressure refers to the
pressure with high osmotic pressure
inside the cell.
•Greater concentration inside
•Less concentration outside
•Shrinkage of cell

19. Hypotonic pressure
Hypotonic pressure refers to the
pressure with low osmotic pressure
inside the cell.
•Lower concentration inside
•Higher concentration outside
•Cell become turgid

20. IsotonicPressure
Pressure exerted by the solution in
which external solution has same
solute and water concentration
compared to body fluids.
•Same pressure inside and outside
of the cell.
•Cell environment remain normal.

21. Diffusionacross
membrane
Passive diffusion is the simplest
,mechanism by which molecule moves
across the cell membrane.
▪Simply dissolve in the phospholipid layer
▪Diffuse across it
▪And then dissolve in the aqueous
solution

22. MembranePotential
▪Membrane potential is the electric
potential that exist across the cell
membrane.
▪It is the wave of electrochemical
changes that travel along the length of
the neuron.

23. MembranePotential

24. Typesof Membrane Potential
Membrane
Potential
RMP AMP

25. RestingMembrane Potential
▪When the membrane is at rest it is more
electropositive outside and
electronegative inside.
▪Also called as Non-conducting neuron.
▪When the membrane is at rest it is in the
Polarized state.

26. Continue…
▪Most important ions are Na+, and K+ Ions.
▪Sodium ions are high in concentration in outside.
▪While K+ ion are high in concentration in inside.
▪Certain channels like:
▪Voltage Gated Channels
▪Na+ K+ ATPase Channel
▪Ligand Gated Channel

27. Continue…
Na+, K+ ions Movement:
▪These movements are driven by
splitting of ATP
▪Two K+ ions are pumped inside.
▪Three Na+ ions Are Pumped Outside.
▪Membrane Potential at rest is -70mV

28. ActionMembrane Potential
▪Potential in action
▪Also called the depolarized state.
▪In AMP Outside becomes Negative And
inside becomes Positive.
▪In AMP, Na+ Gates open And Na+ moves
inside.
▪And K+ gates open and K+ moves
outside.

29. Continue…
▪Membrane Potential during
AMP is 50mV.

30. Phases…
Following are the five phases of AMP:
▪RMP Polarized State
▪Depolarization:
Na+ Gate Open
K+ Gate Close
▪Action Potential Phase:
Na+ Gate Close
K+ Gate Open
▪Repolarization:
K+ Gate Open
K+ ion move outside
▪Recovery of Resting Membrane
Potential.

32. Thank you