Protoplasm
- Also known as bioplast.
- It is gelly like & semi liquid in appearance.
- It is translucent in nature.
- It is colourless, oderless, viscous, elastic & granular in nature.
- Protoplasm is essential for life.
- Protoplasm is the fluid along with all the structures of cell bounded with in the limits of cell membrane.
- Protoplasm includes plasmalemma, cytoplasm & nucleus.
- Different types of granules are embeded in it, capable to perform all vital activities, so protoplasm is vector for vital activities.
- Strusburger differentiated protoplasm into somatoplasm & germplasm in body.
- In Amoeba somatoplasm & germplasm are not differentiated so body is known as soma.
- Main component of protoplasm is water, functions as solvent.
- By increasing age water conetents are reduced so activity becomes dull.
- In dorment seed water is less as a result seeds are inactive.
- According to Renke & Roderwald analysis of protoplasm is not possible in living state because most of the reactions are exothermic.
- On analysis water, CO & amonia are formed.
- Due to proteins protoplasm is coloidal in nature.
- It is polyphagic and reversible.
- Acidic group of protein controls chemical equilibrium.
- Protoplasm is crystallo-colloidal mixture, explained by Fisher & Hardy.
- It's particle size is .001m to .1m..
- In colloidal sol, gel, arosol & emulsion are clear.
- Except arosol remaining 3 present in living system.
- Colloidal system is composed of 2 stages-
(i) Dispersion phase/ Continuous form / Intermicellus
(ii) Dispersed phase/ discontinuous form/ micellus
- On the basis of these 2 stages, colloids are of following types -
(A) Sol - Dispersion phase is liquid. Dispersed phase is solid. In sol stage protoplasm in less viscous. Sol stage occure in many living cells. It is less granular. Protein chain is more folded.
(B) Gel - Dispersion phase is solid. Dispersed phase is liquid. Protoplasm is more viscous. It is more granular. Protein chain is unfolded.
- Sol stage provides - Cyclosis, Brownian movements, High reactivity to protoplasm.
- Gel stage provides - Elasticity, Contractibility, Rigidity, Viscosity
- Sol gel stages are interchangeable, so protoplasm is a reversible colloidal system.
- Non-living colloids are irreversible.
- Protoplasm has motion because of cyclosis, brownian movement & amoeboid movement.
- These movement depends on - age of cells, amount of water, genetic factors, chemical composition of protoplasm.
- With increase in age, brownian movement is stoped.
- So, ultimately it becomes inactive i.e. death of protoplasm.
- Mg+2 controls sol gel stages.
- Sol gel conversion is a physico chemical reaction.
(c) Emulsion
- Two liquids of different density are mixed, e.g. haemolymph.
(d) Aerosol
- Solid particles are dispersed in gas.