Proteins Flashcards
What are amino acids
Monomers from which proteins are made from
What is the structure of amino acids
R
I
Nh2—c—cooh
I
H
What does the nh2 represent in the amino acid structure
Amine grouo
What does the cooh represent in the amino acid structure
Carboxyl group
What does the r represent in the amino acid structure
Side chain
How is a peptide bond formed
In a condensation reaction between 2 amino acids releasing a water molecule
How are dipeptides formed
In a condensation reaction between 2 amino acids
How are polypeptides formed
Formed by the condensation reaction of many amino acids
What are the 4 structures of proteins
Primary
Secondary
Tertiary
Quaternary
What is the primary structure of a protein
Sequence of amino acids that make up the polypeptides of a protein
What is the secondary structure of a protein and give an example
Hydrogen bonds form between amino acids causing them to coil into an alpha helix shape or fold into a beta pleated
sheet
Channel proteins
What is the tertiary structure of a protein and give an example
3d shape of a polypeptide chain held by hydrogen bonds, ionic bonds and disulfide bridges
A change in the sequence of amino acids will affect the secondary and tertiary structure as the bonds form in different
places
Enzymes
What is the quaternary structure of a protein and give an example
More than one polypeptide chain held together
Haem group in haemoglobin
What test is used to find the presence of a protein
Biuret test
Describe the biuret test
Add a few drops of the biuret reagent to the sample
If proteins are present colour will change from blue to purple
Not present colour will stay blue
