Physical-chemical

properties of biopolymers.

TheThe high-molecular compounds (HMC) high-molecular compounds (HMC) are compounds – polymers, which are compounds – polymers, which have 10000 – 10000000 Da (Dalton – have 10000 – 10000000 Da (Dalton – unit of atomic mass) molecular mass.unit of atomic mass) molecular mass.

А А polymerpolymer is а large molecule formed is а large molecule formed by the covalent bonding of repeating by the covalent bonding of repeating smaller molecules.smaller molecules.

For example natural macromolecules: For example natural macromolecules: polysaccharides: glycogen, cellulose, polysaccharides: glycogen, cellulose, starch, proteins, nucleic acids: RNA, starch, proteins, nucleic acids: RNA, DNA.DNA.

Biological role of polymers BiopolymersBiopolymers, , have a lot functionshave a lot functions:: Catalytic Catalytic effecteffect– – enzymesenzymes;; As regulators – hormonesAs regulators – hormones;; is the storage and transfer of genetic

information.((DNADNA);); Storage energy ((StarchStarch, , glycogenglycogen);); Protection - immunoglobulinProtection - immunoglobulin;; Structural Structural ((collagencollagen, , keratinskeratins, , fibrilfibril). ).

CLASSIFICATION HMCCLASSIFICATION HMC

Polymers are classified by different possible:

Classification by source, Classification by structure, Classification by synthesis, Classification by molecular forces.

Classification by source

Natural (nucleic acids, polysaccharides, protein, natural rubber (polyisoprene));

Synthetic (polyethelene, teflon, polyvinilchloride, polystyrene).

Classification by structureLinear polymers. In these polymers,

the monomers are joined together to form long straight chains of polymer molecules. Because of the close packing of polymer chains, linear polymers have high melting point, high densities and high tensile (pulling) strength.

Branched chain polymers. In these polymers, the monomer units not only combine to produce the linear chain (called the main chain) but also form branches along the main chain

Three-dimensional network polymers. In these polymers, the initially formed linear polymer chains are joined together to form а three-dimensional network structure.These polymers are also called cross-linked polymers

ІІІ. By molecule form Globular. Fibril.

By nature atoms, which are in molecule of polymer

Carbon contain polymers

Hetero polymers

Element organic

Inorganic

Synthesis of polymersSynthesis of polymers Addition

polymerization occurs when unsaturated monomers react to form а polymer. It is а specific type of addition reaction.

CondensationCondensation Condensation polymers are formed by the head-to-tail joining of monomer units. This is usually accompanied by the loss of а small molecule, such as water.

Properties

Properties HMC solution, which same as true solutions:

Solutions of high-molecular compounds are stable as molecular solutions;

Solutions of high-molecular compounds are convertible. If high-molecular compound was solved that the molecular solution will be farmed. And if this solution to strip to dryness, so high-molecular compound was stat, which can solve again.

Between high-molecular compound and solvent has not boundary.

Properties HMC solution, which same as colloidal solutions:Size of disperse phase in solutions of high-molecular compounds are same as in colloidal solutions (10-7 - 10-9 m);High-molecular compounds can not permeate through semipermeable membrane;High-molecular compounds slowly are diffused in solutions.Specific properties HMC solution:For solutions of high-molecular compounds are characteristic the swelling and high viscosity

Swelling Swelling it is process solubilityit is process solubility high-high-molecular compound in solvent. molecular compound in solvent.

Swilling degree Swilling degree (α):(α): α = (α = (mm – – mm00)/)/mm00 = = mmpp//mm00

oror α = ( α = (VV – – VV00)/ )/ VV00 = = VVPP / / VV00

Where: Where: mm00 andand V V00 – – massmass or volumeor volume polymer polymer before swillingbefore swilling; ;

mm andand V – V – massmass or volumeor volume polymer after swillingpolymer after swilling; ; mmpp, V, Vpp – – massmass or volumeor volume of solvent, which is of solvent, which is

absorbed polymerabsorbed polymer. . Some time used mass-volume swilling degree: Some time used mass-volume swilling degree: α= α=

((VV00 – – VV)/ )/ mm = = ccмм33//gg

or or α = (α = (VV00 – – VV)100%/)100%/mm