Structure of Proteins & Biuret Test Flashcards
What is the structure of proteins determined by?
The order and number of amino acids, bonding present and the shape of the protein
What is the primary structure of a protein?
The order and number of amino acids in a protein.
What does the primary structure of a protein contain?
The initial sequence of amino acids
What does the primary structure of a protein determine?
The proteins function in the end
What is the secondary structure of a protein?
The shape that the chain of amino acids makes - either alpha helix or beta pleated sheet.
The hydrogen in the -NH has? (Secondary structure)
A slight positive charge
The oxygen in the -C=O has? (Secondary structure)
A slight negative charge
In the secondary structure what can weak hydrogen bonds forming lead to?
Alpha helices or beta pleated sheets
What is the tertiary structure of a protein?
The 3D shape of the protein
How is a tertiary structure formed?
From further twisting and folding
What are disulphide bridges?
Interactions between the sulphur in the R group of the amino acid cysteine. These are strong and not easily broken
How are ionic bonds in the tertiary structure?
Form between the carboxyl and amino groups that are not involved in the peptide bond. They are easily broken by pH and are weaker than disulphide bridges
How are hydrogen bonds in the tertiary structure?
Numerous and easily broken
What are the 2 types of proteins?
Globular and fibrous
Give an example of a globular protein
Enzymes
