Natural Polyamides - Proteins & Amino Acids
Chemistry: Cambridge International GCSE Supplement, topic 11.8.10
Natural Polyamides: Proteins and Amino Acids
Proteins are natural polyamides formed from amino acid monomers via condensation reactions (peptide bonds), releasing water. Their structure defines their vital roles in the body.
Introduction to natural polyamides
- Natural polyamides are polymers found in living things.
- Proteins are natural polyamides made of amino acid monomers.
- The structure of proteins determines their functions.
- Amino acids link together to form proteins by peptide bonds.
Structure of amino acids
- Each amino acid has a central carbon atom.
- The central carbon attaches to:
- An amine group (-NH2)
- A carboxyl group (-COOH)
- A hydrogen atom (-H)
- A variable side group (R)
- The side group (R) changes in different amino acids.
Formation of proteins by condensation
- Proteins form when amino acids join in a chain.
- The amine group reacts with the carboxyl group.
- A molecule of water (H2O) is released in this condensation reaction.
- The bond formed is called a peptide bond.
- Many peptide bonds create a polyamide chain (protein).
Importance of proteins in the body
- Proteins perform many functions, such as:
- Building cells and tissues.
- Acting as enzymes to speed up reactions.
- Supporting immune defence.
- Their natural polyamide structure is key to their function.
- Proteins' shapes depend on the sequence and type of amino acids.
Test yourself on Natural Polyamides - Proteins & Amino Acids
Which of the following functional groups is always present in an amino acid, besides the variable side group (R)?