Proteins Flashcards
What monomers form proteins?
Amino acids
How are dipeptides formed?
Two amino acids join together through a condensation reaction to form a peptide bond with the removal of a water molecule
How are polypeptides formed?
Polypeptides are formed through multiple reactions of amino acids forming peptide bonds and the removal of water molecules
How many levels of structure are there for proteins? What are the levels called?
There are four levels: primary structure, secondary structure, tertiary structure and quaternary structure
What is the first level of structure for proteins?
The primary structure
What is the primary structure?
The primary structure is the order and number of amino acids in a polypeptide chain, a polymer
What is the secondary structure?
The secondary structure is the shape that the chain of amino acids makes, forming either alpha helix or beta pleated sheets.
How does the secondary structure form the alpha helix or beta pleated sheets?
The hydrogen in the -NH has a slight positive charge whilst the oxygen in the -C=O has a slight negative charge. As a result weak hydrogen bonds can form leading to the alpha helices or beta pleated sheets
What are disulfide bridges?
Disulfide bridges are interactions between the sulfur in the R group of the amino acid cysteine these are stroonf and not easily broken
What is the tertiary structure?
The tertiary structure is the further folding of the secondary structure, forming a unique 3D shape. This is held by ionic, hydrogen and disulphide bonds.
What are ionic bonds?
Ionic bonds 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 disulfide bridges
What are hydrogen bonds?
