 Section 1: Living organisms: variety and common features
Biological molecules
Name ______________________________________________
Date ____________
1 Match the start of each sentence in column one with the most suitable ending from column two.
Start of sentence
Sentence ending
Maltose and sucrose are …
… an insoluble polysaccharide found in animals
Cellulose is …
… simple sugars composed of the elements carbon, hydrogen
and oxygen only
Glycogen is …
… an insoluble storage polysaccharide in plants
Starch is …
... disaccharide sugars
Monosaccharides are …
… a polysaccharide found in cell walls
[5]
2 Proteins are an essential part of a balanced diet.
a) What are the building blocks of proteins called?
[1]
____________________________________________________________________
b) Name the following protein types:
i
the protein found in hair and nails
[1]
_______________________________________________________________
ii a protein found in ligaments
[1]
_______________________________________________________________
iii a protein that carries oxygen.
[1]
_______________________________________________________________
c) What is the name of the reagent that is used to test for the presence of proteins in
solution?
[1]
____________________________________________________________________
Edexcel International GCSE (9–1) Biology
© Hodder & Stoughton 2018
1
 Section 1: Living organisms: variety and common features
Biological molecules
d) Describe how the test for protein would be carried out.
[2]
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
e) What would be observed if protein was present in the solution?
[1]
____________________________________________________________________
3 The diagram below shows an experimental procedure used to test for glucose.
a) A few drops of a reagent are added to the sample solution. What is the name of this
reagent?
[1]
____________________________________________________________________
Edexcel International GCSE (9–1) Biology
© Hodder & Stoughton 2018
2
 Section 1: Living organisms: variety and common features
Biological molecules
b) Describe what is happening in part B of the diagram.
[2]
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
c) Tubes 1, 2 and 3 show the results obtained when three different solutions were
tested. Explain the results shown for each tube.
[3]
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
d) If you wanted to show that starch was present in a solution, what reagent would be
used and what colour change would be observed?
[2]
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
e) Describe the main differences between the structures of starch and glucose.
[2]
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
Edexcel International GCSE (9–1) Biology
© Hodder & Stoughton 2018
3
 Section 1: Living organisms: variety and common features
Biological molecules
4 The diagram below shows the reaction between an enzyme and a substrate.
a) Name parts X and Y.
[2]
X ____________________________________________________________________
Y ____________________________________________________________________
b) Which is the correct substrate for the enzyme? Explain your answer.
[2]
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
Edexcel International GCSE (9–1) Biology
© Hodder & Stoughton 2018
4
 Section 1: Living organisms: variety and common features
Biological molecules
c) Using information in the diagram, explain what is meant by the lock and key
theory.
[3]
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
d) Explain what is meant by the term denaturing.
[1]
____________________________________________________________________
____________________________________________________________________
e) Give two ways in which an enzyme can be denatured.
[2]
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
5 Complete the table by filling in the blank boxes.
Description of molecule
Name of molecule
[8]
Building block of molecule
Found in plant cell walls
Haemoglobin
Found in cell membranes; doesn’t mix with
water
A storage carbohydrate in plants
Edexcel International GCSE (9–1) Biology
© Hodder & Stoughton 2018
5