PHYSICAL PROPERTIES OF PROTOPLASM -
1. Phase reversal - Due to difference in temperature outer part is gel and inner part of sol
2. Tyndall effect - Being colloid, protoplasm exhibits "Tyndall effect" i.e. scattering of incident light rays. If colloid particles are large, Then white and if they are small then blue light is absorbed.
3. Elasticity & Contractility - It is due to folding and unfolding nature of protein. Protoplasm can spread 25 times to its form.
4. Surface Tension - Being a liquid mixture the protoplasm have a surface tension. Lipid and protein are having high surface tension, therefore, around cytoplasm plasmalemma is present made up of lipoprotein.
5. Viscosity - 2 - 20 centipoises
6. pH - 6 - 8
7. Refractive index - 1.4
8. Coagulation - Coagulate at 60ºC on reacting with acid and base.