RPA - polymers Flashcards
What is the name of polymers formed from amino acids?
Polypeptides
What is the type of reaction involved in synthesis of polypeptides?
Condensation reaction (elimination of H2O)
What is the linkage formed when amino acid polymerised?
Amide group O=C-N-H
What is the difference between polypeiptide and protein?
Protein has at least 50 protein monomers
What are the possible products when two amino acids react?
the first bonded to second, the second bonded to first/ Normally written Nā>C
What group of polymers are polypeptides in?
polyamides
What is the other way of synthesizing polyamide without amino acid?
di-amine and dicarboxylic acid to form amide bond
when a polypeptide is hydrolised in acid, what is are the products?
Ammonium ion (protonated amine group) normal carboxylic acid group
What is the product when a polypeptide is hydrolyzed in alkali solution?
Amino acid with COO-Na+ ion
What are the conditions when polypeptide undergoes acid hydrolysis?
6M HCl
25H reflux
what are the conditions when polypeptide is hydrolyzed in alkali?
100 C
NaOH(aq)
What are the two types of condensation polymers?
Polyamides, polyesters
How to you separate amino acids having hydrolyzed it?
TLC
Where do you measure the Rf value from?
Top of the spot.
What are the two ways of forming a polyester?
dicarboxylic acid + diol
e.g. 3-hydroxy butanoic acid
When polyester formed, where are the groups lost to eliminate water?
OH from COOH, H from -OH
What are the products from when polyesters hydrolyzed in acid conditions?
Just monomers formed (dicarboxylic acid/diol)
What are the products when polyesters hydrolyzed in alkali conditions?
Carboxylate salt formed, alcohol formed as normal.
What are the products when polyamides hydrolyzed in acid conditions?
carboxylic acid + ammonium salt of amine (H3N+)
What are the producs when polyamides hydrolyzed in alkali conditions?
Di-carboxylate ion and amine.
What is characteristic of an amide bond?
O=C-N-H
What two types of monomers are required for synthesis of polyamide?
Diamine + dicarboxylic acid
What does it mean if a polyester is biodegradable?
It can be hydrolzed by microorgnisms to reform the monomers
Give two uses of polyamides
nylon, kevlar
In a polyester synthesized from dicarboxylic acid + diol, what is the repeat unit?
One section of diarboxylic acid + diol containing one ester linkage
In polyamide synthesized from diamine + dicarboxylic acid, what is the repear unit?
one section of dicarboxylic acid + diamine with one amide bond
How can a polyester be formed from a single monomer?
use a carboxylic acid w/hydroxyl group e.g. 3-hydroxy butanoic acid
How can a polyamide be formed from a single monomer unit?
Use carboxylic acid with amine group on the other end i.e. amino acid
What is the stoichiometric ratio of monomer:polymer:water molecules in condensation polymerisation?
n:n:(2n-1)
Why is the stoichiometric ratio for water molecules 2n-1?
For each ester/amide linkage, one molecule of water is lost. Each monomer is linked to the loss of two molecules of water (one from each end), and except for the final link in the chain, which remains with hydrogens
