Introduction to Osmosis: Mechanism, Factors, Types, and Applications

This presentation provides an introduction to the process of osmosis, its mechanism, factors influencing it, types of solutions, and applications in kidney dialysis. Osmosis is a spontaneous movement of solvent from lower solute concentration to higher concentration through a selectively permeable membrane. The presentation also discusses the importance of osmosis in maintaining the balance between water and intercellular fluid, distributing nutrients and minerals, and getting rid of waste material. The presentation is relevant to biology and physiology courses and is useful for students in college and university.

Osmosis
Presented by:

Introduction to Osmosis
 Process helps to equalize the concentration of two solutions
having different solute concentration.
 Spontaneous movement of solvent occurs from lower solute
concentration to higher concentration.
 Process occurs through selectively permeable membrane
that is permeable to solvent but not to the solute.
 External pressure known as osmotic pressure is required to
prevent the inward flow of the solution through the semi-
permeable membrane (Shaffer et al 2013)

Mechanism in Cell
The extracellular fluids enters the cytoplasm through protein
channels in the plasma membrane in order to stabilize the
water concentration in the cell.
 Plasma membrane acts as the semi permeable membrane in
the process (Chiras, 2013).

Factors Influencing Osmosis
Two major factors influence the process of
osmosis
OSMOTIC PRESSURE:
 Pressure per unit area that is required to prevent the water
inflow from lower concentration to higher concentration
through the selectively permeable membrane.
 It depends on the concentration of the solute but not on the
density (Shaffer et al 2013).

Factors Influencing Osmosis
OSMOTIC GRADIENT:
 It is the difference between the concentration of the
two solution.
 Defines the difference in the percentage of a particular
molecule dissolved in the solution.
 Higher the difference in the concentration higher the
rate of flow of the solvent (Shaffer et al 2013).

Types of Solution
ISOTONIC:
Concentration of the solute particles is equal in both the inside and
outside of the cell.
No net movement across the cell.
HYPERTONIC:
Concentration of the solute is greater in the outside of the cell than
the inside.
Water flows outside of the cell and the cell shrinks and becomes
flaccid.
HYPOTONIC:
Concentration of the solute is greater inside the cell than the outside.
Water flows from the outside to the inside of the cell; the cell swells
and becomes turgid (Shaffer et al 2013).

Condition of Red Blood Cell in Three
Different Solutions
 The red blood cell is placed in the
hypertonic solution containing salt,
the cell loses water and shrinks due
to osmosis.
 The cell is placed in a equal
concentrated solution, no net flow of
water, thus, the cell stays same.
 the cell is placed in pure water
that is hypotonic solution, water
enters the cell, the cell swells and
burst due to osmosis (Chiras 2013).

Importance of Osmosis
 Maintain the balance between water and intercellular fluid.
 Root cells of plants receive water through osmosis.
 Distributes nutrients and minerals in the organisms.
 Helps a cell to get rid of waste material.
 Movement of water from cell to cell occurs through osmosis.
 Prevent plants from drought.
 Maintain the shape of the cell through maintaining turgidity (Koeppen and
Stanton 2017).

Application of Osmosis; Kidney
Dialysis:
 Kidney dialysis machine uses the process of osmosis to
carry out the filtering function of the kidney.
 Semi permeable membrane is placed between the blood
and dialysis solution.
 The semi permeable membrane in the dialysis machine
allows the movement of water salt and metabolites but not
the blood cells and proteins (Levy, Brown and Lawrence
2016).

Application of Osmosis; Kidney
Dialysis:
 Due to osmosis, the metabolites and electrolytes flow out of
the blood into the dialysis solution.
 Blood get rid of toxic metabolites and extra electrolytes and
the process maintain the normal function of the kidney
(Levy, Brown and Lawrence 2016).

REFERENCES:
Aspinall, V. and Cappello, M., 2015. Introduction to Veterinary
Anatomy and Physiology Textbook-E-Book. Elsevier Health Sciences.
Chiras, D.D., 2013. Human biology. Jones & Bartlett Publishers.
Koeppen, B.M. and Stanton, B.A., 2017. Berne and Levy Physiology
E-Book. Elsevier Health Sciences.
Levy, J., Brown, E. and Lawrence, A., 2016. Oxford handbook of
dialysis. Oxford University Press.
Shaffer, D.L., Werber, J.R., Jaramillo, H., Lin, S. and Elimelech, M.,
2015. Forward osmosis: where are we now?. Desalination, 356,
pp.271-284.

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