RPA - polymers

Question 1

What is the name of polymers formed from amino acids?

Answer 1

Polypeptides

Question 2

What is the type of reaction involved in synthesis of polypeptides?

Answer 2

Condensation reaction (elimination of H2O)

Question 3

What is the linkage formed when amino acid polymerised?

Answer 3

Amide group O=C-N-H

Question 4

What is the difference between polypeiptide and protein?

Answer 4

Protein has at least 50 protein monomers

Question 5

What are the possible products when two amino acids react?

Answer 5

the first bonded to second, the second bonded to first/ Normally written N–>C

Question 6

What group of polymers are polypeptides in?

Answer 6

polyamides

Question 7

What is the other way of synthesizing polyamide without amino acid?

Answer 7

di-amine and dicarboxylic acid to form amide bond

Question 8

when a polypeptide is hydrolised in acid, what is are the products?

Answer 8

Ammonium ion (protonated amine group)
normal carboxylic acid group

Question 9

What is the product when a polypeptide is hydrolyzed in alkali solution?

Answer 9

Amino acid with COO-Na+ ion

Question 10

What are the conditions when polypeptide undergoes acid hydrolysis?

Answer 10

6M HCl

25H reflux

Question 11

what are the conditions when polypeptide is hydrolyzed in alkali?

Answer 11

100 C

NaOH(aq)

Question 12

What are the two types of condensation polymers?

Answer 12

Polyamides, polyesters

Question 13

How to you separate amino acids having hydrolyzed it?

Answer 13

TLC

Question 14

Where do you measure the Rf value from?

Answer 14

Top of the spot.

Question 15

What are the two ways of forming a polyester?

Answer 15

dicarboxylic acid + diol

e.g. 3-hydroxy butanoic acid

Question 16

When polyester formed, where are the groups lost to eliminate water?

Answer 16

OH from COOH, H from -OH

Question 17

What are the products from when polyesters hydrolyzed in acid conditions?

Answer 17

Just monomers formed (dicarboxylic acid/diol)

Question 18

What are the products when polyesters hydrolyzed in alkali conditions?

Answer 18

Carboxylate salt formed, alcohol formed as normal.

Question 19

What are the products when polyamides hydrolyzed in acid conditions?

Answer 19

carboxylic acid + ammonium salt of amine (H3N+)

Question 20

What are the producs when polyamides hydrolyzed in alkali conditions?

Answer 20

Di-carboxylate ion and amine.

Question 21

What is characteristic of an amide bond?

Answer 21

O=C-N-H

Question 22

What two types of monomers are required for synthesis of polyamide?

Answer 22

Diamine + dicarboxylic acid

Question 23

What does it mean if a polyester is biodegradable?

Answer 23

It can be hydrolzed by microorgnisms to reform the monomers

Question 24

Give two uses of polyamides

Answer 24

nylon, kevlar

Question 25

In a polyester synthesized from dicarboxylic acid + diol, what is the repeat unit?

Answer 25

One section of diarboxylic acid + diol containing one ester linkage

Question 26

In polyamide synthesized from diamine + dicarboxylic acid, what is the repear unit?

Answer 26

one section of dicarboxylic acid + diamine with one amide bond

Question 27

How can a polyester be formed from a single monomer?

Answer 27

use a carboxylic acid w/hydroxyl group e.g. 3-hydroxy butanoic acid

Question 28

How can a polyamide be formed from a single monomer unit?

Answer 28

Use carboxylic acid with amine group on the other end i.e. amino acid

Question 29

What is the stoichiometric ratio of monomer:polymer:water molecules in condensation polymerisation?

Answer 29

n:n:(2n-1)

Question 30

Why is the stoichiometric ratio for water molecules 2n-1?

Answer 30

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