Bio Physical properties lecture 3

2. Biophysical Properties – Lecture -3
Learning Objectives:
Students will be able to:
• Define Solution & Types of Solution
• Colloids & Classification
• Crystalloid & Classification
• Biological Significance of Colloids Professor Dr. Syed Irfan Raza
PhD Biochemistry

3. S O L U T I O N S
Solution
Solute
Solvent

4. Percentage concentration is a measure of the amount of solute dissolved in
every 100 units of solution.
9% Saline: 9g/100ml of solution
Smaller concentrations: mg 10-3g, ug 10-6g, ng 10-9g, pg 10-12g
Parts per Million ppm: 10ppm chlorine means 10ug of chlorine in
1 g of water
S O L U T I O N S

5. S O L U T I O N S
Molarity is defined as the number of moles of solute per liter of solution.
How much is 1 mole in grams?
One mole of a substance is equal to 6.022 × 10²³ units of that substance
(such as atoms, molecules, or ions). (Avogadro's number)
One mole of a substance is equal to its atomic or molecular weight
taken in grams.
For instance 1 mole of H2O = 1x2 + 16 = 18g

6. S O L U T I O N S
Prepare 1 Molar NaCl Solution?
Prepare 1 molar solution of NaCl
NaCl molecular weight = 23 + 35.5 = 58.5 grams
To prepare 1 Molar NaCl = 58.5 g of NaCl in a cylinder + 1000ml of H2O
How you will prepare 0.1L of 1.7M KCl solution?

7. S O L U T I O N S
Molality is defined as the number of moles of solute per 1000 g of
solvent solution.
1 Molal solution = 1mole of solute dissolved in 1000 g of solvent
Normality is defined as the gram equivalent weight of an element or
compound represents its capacity to combine or replace 1 Mole of
Hydrogen.

8. 1.Define pH
2.Define Buffers & its composition
3.What are acidic & basic buffers?
4.Define Molar, Molal and Normal Solution
5.What are percentage Solution – Biological significance

9. S O L U T I O N S
Colloid: A colloid is a mixture that has particles ranging between 1 and
1000 nanometers in diameter, yet are still able to remain evenly
distributed throughout the solution. These are also known as colloidal
dispersions because the substances remain dispersed and do not settle
to the bottom of the container.
Thomas Graham 1861 –
divided substances into two classes – Crystalloids & Colloids

10. S O L U T I O N S
Solution = 0.01 - 1nm.
Suspension = 1 – 50 um
Colloids = 1 - 100 nm

11. S O L U T I O N S
Crystalloids:
Crystalloid solutions, which contain water-soluble electrolytes
including sodium and chloride, lack proteins and insoluble
molecules. They are classified by tonicity, so that isotonic
crystalloids contain the same amount of electrolytes as the plasma.

12. Crystalloid Solutions:
• A crystalloid solution is an aqueous solution composed
of water and small solutes such as electrolytes and
glucose.
• Crystalloid solutions can be categorized based on
whether they are hypotonic, isotonic, or hypertonic.
• Tonicity describes the effective osmolality of a fluid,
which is the ability of a fluid to alter water movement
across the cell membrane.

13. S O L U T I O N S
Colloidal state:
Colloids exist either in the form of colloidal state or colloidal system.
Particle size = 1 – 100nm
Phases of Colloids:
Dispersed phase or Internal phase
Which constitute colloidal particle
Dispersion phase or external phase
Medium in which the colloidal
particles are suspended

14. Classification of Colloids
2. Lyophilic:
Have affinity with dispersion medium
- Water is the dispersion medium
1. Lyophobic:
Don’t not have any attraction towards dispersion medium
– Water is dispersion medium
3. Gel & Sol:
Jelly like & Solution like colloids
4. Emulsions:
Formed of two immiscible liquids (Oil + Water)
Lyophilic colloids are more stable

15. Biological Important Colloids
1. Biological Fluids Colloids- Blood, Milk, CSF
2. Biological Compounds Colloidal particles-
High Mol. Wt. Proteins, Complex lipids, Polysaccharides
3. Blood Coagulation-
During blood coagulates sol is converted to gel
4. Fat digestion & absorption-
Emulsion formation by bile's salts promotes fats digestion.
5. Formation of urine
Urine filtration is based on the principle of dialysis .