1.1 Monomers and polymers

Question 1

monomers

Answer 1

smaller units from which larger molecules are made

Question 2

polymers

Answer 2

are molecules made from large number of monomers joined together

Question 3

Define monosaccharide.

Answer 3

the monomers from which larger carbohydrates are made
single sugar units

Question 4

what are examples of monomers

Answer 4

monosaccharides, amino acids and nucleotides

Question 5

Name the type of reaction that joins monosaccharides together.

Answer 5

condensation

Question 6

Define hydrolysis reaction

Answer 6

A reaction that breaks a chemical bond between two molecules
use of a water molecule

Question 7

Define condensation reaction.

Answer 7

A reaction that joins two molecules together
with the formation of a chemical bond

elimination of a molecule of water.

Question 8

Describe the biochemical tests you would use to confirm the presence of lipid, non-reducing sugar and amylase in a sample.

Answer 8

Lipid
1.   Add ethanol/alcohol then add water and shake/mix
2.   emulsion test turns white/milky;

Non-reducing sugar
3.   Do Benedict’s test and stays blue/negative;
4.   Boil with acid then neutralise with alkali;
5.   Heat with Benedict’s and becomes red/orange precipitate

Amylase
6.   Add biuret (reagent) and becomes purple/violet/mauve/lilac;
sodium or potassium hydroxide and copper sulfate
Reject heating biuret test.
7.   Add starch, (leave for a time), test for reducing sugar/absence of starch;

Question 9

Describe the chemical reactions involved in the conversion of polymers to monomers and monomers to polymers.
Give two named examples of polymers and their associated monomers to illustrate
your answer.

Answer 9

1. A condensation reaction joins monomers together and forms a (chemical) bond and releases water
2. A hydrolysis reaction breaks the (chemical) bond between monomers and uses water
3. A suitable example of polymers and monomers from which they are made
4. A second suitable example of polymers and the monomers from which they are made
5. Reference to a correct bond within a named polymer
   Suitable Example =
   Amino Acids –> Polypeptide/Protein/Enzyme/Antibody
   Nucleotides –> Polynucleotide/DNA/RNA
   Alpha Glucose –> Starch/Glycogen
   Beta Glucose –> Cellulose