1.6 protein Flashcards
What is the monomer of a protein
Amino acid
What is the polymer of protein called
Polypeptide
What is the structure of amino acid
Carbons atom which is always found in the middle
Amino group on the left of the carbon NH2
Carboxyl group on the right of the carbon atoms (C,O,OH)
Hydrogen atom at top of carbon atom
R which is the variable group at the bottom of carbon atom
What is it called when 2 amino acids are joined together
Dipeptide
How are the amino acids joined together
They go through a condensation reaction and form a peptide bond
What is polymerisation
Series of condensation reactions between many amino acids
What happens if a change occurs in a single amino acid in the primary sequence
The result would be that the protein would not be able to perform it’s function because the shape of a protein is important to it’s function
What is the secondary structure of proteins
It is a coil known as a alpha-helix. This is formed through hydrogen bonds
How are amino acids linked in a secondary structure
The linked amino acids that make up a polypeptide possess both
- NH and -C=O on either side of every peptide bond NH has had overall positive charge O has a overall negative charge and therefore these 2 groups make a weak hydrogen bond
How is a tertiary structure formed
The alpha helix is twisted or folded even more to give complex, specific and 3-D structure of each protein
What are the different bonds present in a tertiary structure of a protein
Disulfide bridge
Ionic bonds
Hydrogen bonds
What determined the 3-D shape of a protein
Sequence of amino acids determines the shape of a protein
What is the name of a protein test
Biuret test
How is a Biuret test conducted
Place sample of solution in test tube and add equal amount of sodium hydroxide solution at room temperature
Add few drops of dilute(0.005%) Cu(II) sulfate solution and mix gently
A purple colouration indicates the presence of a peptide bond and hence a protein. If protein is not present solution will remain blue
