Biological molecules PowerPoint for revision.

1. Link to CAIE Specification
2.2 Carbohydrates and lipids
Learning Objectives
Candidates should be able to:
● define the terms monomer, polymer,
macromolecule,
● state the role of covalent bonds in joining smaller
molecules together to form polymers

2. STARTER
A
Activity : 1 Revisiting Igcse

3. Activity : 2

4. Activity : 2

5. Activity : 3 Literary Exercise

6. Activity : 3 Literary Exercise

7. Activity : 3
Questions:
1. What atom makes up the backbone of biological macromolecules?
2. What kinds of shapes can carbon based molecules form?
3. What are macromolecules?
4. How are monomers related to polymers?
5.When polymers are built, the process is called a dehydration reaction. Why is the word
“dehydration used?”
6. Organisms not only build molecules, they also break them down. This chemical reaction is
called

8. Activity : 3
Questions:
6. Organisms not only build molecules, they also break them down. This chemical reaction is
called
7. What does the prefix “hydro” and the suffix “lysis” mean?
8.Why does a cell (or your body) need to break down polymers into monomers? Give at least
two reasons for this....
9. Life’s large molecules or “polymers” are classified into what four categories?

9. Activity : 3
Questions:
1. What atom makes up the backbone of biological macromolecules?
Carbon
2. What kinds of shapes can carbon based molecules form?
single and double rings, chains, and branching chains.
3. What are macromolecules?
a large organic molecule
4. How are monomers related to polymers?
If the small organic units are identical or form patterns they are called monomers
and the large organic molecule they form is called a polymer.
5.When polymers are built, the process is called a dehydration reaction. Why is the word
“dehydration used?”
Water is removed to form the bond between monomers
6.Organisms not only build molecules, they also break them down. This chemical reaction
is called Hydrolysis.
7. What does the prefix “hydro” and the suffix “lysis” mean?
Water and Splitting
8.Why does a cell (or your body) need to break down polymers into monomers? Give at
least two reasons for this....
This makes the molecules small enough to cross cell
membranes.
Energy
9. Life’s large molecules or “polymers” are classified into what four categories?
Carbs, Lipids, Proteins, and Nucleic acids

10. Activity : 3 Condensation and hydrolysis

11. Activity : 3 Condensation and hydrolysis

12. • A condensation reaction occurs when two monomers
bond together through the loss of a water molecule
monomers
The Synthesis of Polymers
polymers
Dehydration
Reaction

13. • Polymers are broken down to Monomers by hydrolysis, a
reaction that is essentially the reverse of the dehydration reaction
polymers
Hydrolysis
Reaction
monomers
The Breakdown of Polymers

14. Activity : 4

15. Activity : 4

16. Overview: The Molecules of Life
❖ Macromolecules are large biological molecules composed of
thousands of covalently connected atoms
➢ Molecular structure affects function
❖ All living things are made up of four classes of macromolecules:
➢ Carbohydrates
➢ Lipids
➢ Proteins
➢ Nucleic acids

17. Macromolecules are polymers, built from
monomers
A polymer
• is a giant molecule
• made from many similar repeating subunits
• joined together in a chain;
• the subunits are much smaller and simpler
molecules known as monomers;
• examples of biological polymers are
polysaccharides, proteins and nucleic acids.
© 2011 Pearson Education, Inc.

18. Macromolecules are polymers, built from
monomers
❖ A monomer
❖ is a relatively simple molecule
❖ which is used as a basic building block
❖ for the synthesis of a polymer;
❖ many monomers are joined together to make
the polymer, usually by condensation reactions;
❖ common examples of molecules used as
monomers are monosaccharides, amino acids
and nucleotides.
© 2011 Pearson Education, Inc.

19. starch
cellulose

20. proteins

21. Nucleic Acids - The
DNA

22. lipids
It is important to remember the basic biological definition of "polymer." Several smaller,
similar units in a chain to create a larger molecule with new properties. Lipids tend to be
large, single molecules with no obvious repeating pattern. They are very important as
macromolecules in the life sciences, but alas, they are not polymers.

23. Activity : 5
4

24. Activity : 5

25. Activity : 6

26. ➢ Threeof the fourclasses of life’s organic molecules are
polymers
■ Carbohydrates
■ Proteins
■ Nucleicacids
© 2011 Pearson Education, Inc.

28. Activity : 7

29. Activity : 8