A LEVEL BIOLOGY WITH MR NASH – TOPIC 1 BIOLOGICAL MOLECULES

MOLECULES OF LIFESpecification Point 3.1.1

The variety of life, both past and present, is extensive, but the biochemical basis of life is similar for all living things.

Monomers are the smaller units from which larger molecules are made.

Polymers are molecules made from a large number of monomers joined together.

Monosaccharides, amino acids and nucleotides are examples of monomers.

A condensation reaction joins two molecules together with the formation of a chemical bond and involves the elimination of a molecule of water.

A hydrolysis reaction breaks a chemical bond between two molecules and involves the use of a water molecule.

Lets get started: Making useful molecules

Nylon (a type of plastic) is used for creating synthetic substances.

Complete the chemical reaction below: Tube A contains the building blocks

of nylon. Tube B contains a catalyst. Add tube A to tube B to make

chemical C. Note what happens. Which chemical, A or C, is more

useful? Explain why? What kind of reaction do you think has just happened?

Outcomes:

- Define the terms monomer and polymer

- Describe the reactions that form and break polymers in biological molecules

- Use word and symbol equations to describe condensation and hydrolysis reactions

Polymerisation reaction

Outcomes:

- Define the terms monomer and polymer

- Describe the reactions that form and break polymers in biological molecules

- Use word and symbol equations to describe condensation and hydrolysis reactions

Monomer Monomer

Dimer

Polymer

Definitions

Monomer:

Dimer:

Polymer:

Polymerisation:

Why is any of this important?Proteins, Carbohydrates, DNA, Fats these are all Polymers made of smaller monomer parts.

Outcomes:

- Define the terms monomer and polymer

- Describe the reactions that form and break polymers in biological molecules

- Use word and symbol equations to describe condensation and hydrolysis reactions

Forming Polymers – Condensation reactions

Condensation reaction: forms polymers by reacting the OH with the H.

By product: Water (H2O)

Outcomes:

- Define the terms monomer and polymer

- Describe the reactions that form and break polymers in biological molecules

- Use word and symbol equations to describe condensation and hydrolysis reactions

Breaking down Polymers - Hydrolysis

Hydrolysis: Using water to break apart a polymer.

What do you notice about the condensation reaction and the hydrolysis reaction?

Outcomes:

- Define the terms monomer and polymer

- Describe the reactions that form and break polymers in biological molecules

- Use word and symbol equations to describe condensation and hydrolysis reactions

Why would it be important to build polymers? (Condensation)

Examples of Monomers in Living things:- Glucose- Amino acids- Fatty acids- Nucleic acids

Examples of Polymers in Living things:- Starch- Cellulose- Proteins- Fats- DNA

Why would it be important to break down polymers back into monomers? (Hydrolysis)