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Protein

Key Stage 3

Meaning

Proteins are molecules in our diet that are used by our bodies for growth and repair.

About Proteins

There are many different proteins.
Protein is used to build muscles and repair injuries.
Not enough protein can cause a disease called Kwashiorkor.

Sources of Protein

We can eat any of these foods to get enough protein.
Meat.png
Beans.png
Nuts.png
Peas.png
Meat provides lots of protein for a balanced diet. You can help keep your diet balanced by eating lots of different beans. Nuts are the seeds of trees and are part of a balanced diet. There are many different kinds of peas that can help make sure you have a balanced diet.

Testing For Protein

Adding protein to Biuret solution will cause the solution to turn purple.
Method
1. Take a small sample of food and dissolve it in water.
2. Add some Biuret to the solution.
3. If it turns from blue to purple then the food contained protein.
Biuret.png
This Biuret has turned purple, indicating protein is present.

Key Stage 4

Meaning

Proteins, also known as polypeptides, are large polymer molecules made from amino acids that are used by our bodies for growth and repair.

About Proteins

Proteins (polypeptides) are formed in polymerisation reactions of Amino Acids (peptides).
Proteins are broken down by our digestive systems into amino acids which are then transported around the body by our blood.
Cells build new proteins from amino acids in a process called protein synthesis which takes place at the ribosomes in cells.
Protein is essential to build enzymes which control the metabolic processes inside the cell.
A single protein can be made of millions of amino acids bonded together.
ProteinAminoAcid.png
This diagram represents an amino acid and a small protein made of 3 different amino acids.

Sources of Protein

We can eat any of these foods to get enough protein.
Meat.png
Beans.png
Nuts.png
Peas.png
Meat provides lots of protein for a balanced diet. You can help keep your diet balanced by eating lots of different beans. Nuts are the seeds of trees and are part of a balanced diet. There are many different kinds of peas that can help make sure you have a balanced diet.

Testing For Protein

Adding protein to Biuret solution will cause the solution to turn purple.
Method
1. Take a small sample of food and dissolve it in water.
2. Add some Biuret to the solution.
3. If it turns from blue to purple then the food contained protein.
Biuret.png
This Biuret has turned purple, indicating protein is present.


References

AQA

Polypeptide, page 251, GCSE Chemistry; Student Book, Collins, AQA
Polypeptides, page 173, GCSE Chemistry; Third Edition, Oxford University Press, AQA
Polypeptides, pages 192-3, GCSE Chemistry, Hodder, AQA
Protein, pages 101, 104, 108, 192, 238, 241, 246-7, GCSE Biology; Student Book, Collins, AQA
Protein, pages 226-7, 251, 253, 283, 322, GCSE Chemistry; Student Book, Collins, AQA
Protein, test for, page 48, GCSE Combined Science Trilogy 1, Hodder, AQA
Proteins (test for), page 28, GCSE Combined Science; The Revision Guide, CGP, AQA
Proteins, page 173, GCSE Chemistry; Third Edition, Oxford University Press, AQA
Proteins, page 193, GCSE Chemistry, Hodder, AQA
Proteins, page 246, GCSE Chemistry, CGP, AQA
Proteins, page 84, GCSE Chemistry; The Revision Guide, CGP, AQA
Proteins, page 85, GCSE Biology; The Revision Guide, CGP, AQA
Proteins, pages 34, GCSE Combined Science Trilogy 2, Hodder, AQA
Proteins, pages 41, 46, 48, 129, 141, 204-205, 207, 309, GCSE Biology; Third Edition, Oxford University Press, AQA
Proteins; function of, page 85, GCSE Biology; The Revision Guide, CGP, AQA
Proteins; test for, page 32, GCSE Biology; The Revision Guide, CGP, AQA

Edexcel

Polypeptides, page 59, GCSE Biology, Pearson, Edexcel
Proteins, page 100, GCSE Chemistry; The Revision Guide, CGP, Edexcel
Proteins, page 124, GCSE Biology, Pearson, Edexcel
Proteins, page 17, GCSE Combined Science; The Revision Guide, CGP, Edexcel
Proteins, page 185, GCSE Chemistry, Pearson, Edexcel
Proteins, page 292, GCSE Chemistry, CGP, Edexcel
Proteins, pages 18, 19, GCSE Biology; The Revision Guide, CGP, Edexcel
Proteins, pages 41, 44, GCSE Biology, CGP, Edexcel
Proteins; synthesis, pages 58-59, GCSE Biology, Pearson, Edexcel

OCR

Proteins, page 20, Gateway GCSE Combined Science; The Revision Guide, CGP, OCR
Proteins, page 91, Gateway GCSE Chemistry; The Revision Guide, CGP, OCR
Proteins, pages 16, 23, Gateway GCSE Biology; The Revision Guide, CGP, OCR
Proteins, pages 28, 30-31, 39, 62, 252, Gateway GCSE Biology, Oxford, OCR
Proteins, pages 64, 245, 246, Gateway GCSE Chemistry, Oxford, OCR
Proteins; synthesis, page 16, Gateway GCSE Biology; The Revision Guide, CGP, OCR
Proteins; testing for, page 24, Gateway GCSE Biology; The Revision Guide, CGP, OCR