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Structure of an amino acid
Amino group, NH2, a carboxyl group, COOH, and a variable R group.
What does the R group do?
Determines the chemical properties of the amino acid.
What are amino acids?
Monomers joined by peptide bonds in condensation reactions
What type of reaction forms peptide bonds (linking amino acids)
Condensation reaction
When does a peptide bond form?
When 2 amino acids join together
How many amino acids does a dipeptide contains
2
How many amino acids does a polypeptide contain
3 or more (multiple)
What determines the structure of a protein?
The order and number of amino acids
Bonding present
Shape of the protein
When does a protein form?
When a polypeptide foils or coils or associates with other polypeptide chains.
Is a peptide bond between amino acids strong or weak?
Strong
How is the 3D structure of a protein achieved?
Other bonds going between the amino acids in the chain.
What determines the type of bonds in the protein?
The atoms in the R group
What charge is on the hydrogen
positive charge
What group is the hydrogen in? (in a protein)
amino group
What does the hydrogen bond with and what causes it? (attraction)
Hydrogen bonds with the oxygen as because hydrogen has tiny negative charges and oxygen (of the carboxyl group) has tiny positive charges.
Are hydrogen bonds weak or strong?
Weak
Are there lots or little hydrogen bonds and why?
Lots as they can potentially form between any two amino acids positioned correctly, so there are lots of them in a protein together
What causes hydrogen bonds to break and reform?
pH change
Temperature conditions change
What are hydrogen bonds important for?
The folding and coiling of the polypeptide chains.
When do disulfide bonds form?
When two cysteine bonds are close together in the structure of a polypeptide.
What reaction creates a disulfide bond and what does it take place between?
An oxidation reaction takes place between the two sulfur containing groups.
Which ones are stronger hydrogen bonds or disulfide.
Disulfide bonds
What type of bond is a disulfide bond?
Strong Covalent Bond!!!
What is the primary structure of a protein
a protein is the linear sequence of amino acids in the polypeptide chains, held together by peptide bonds.
How is the secondary structure formed?
formed by the folding of the polypeptide chain into an alpha helix or beta pleated sheet .
What does the secondary structure contain
contains hydrogen bonds (electrostatic forces of attraction between an oxygen, nitrogen or fluorine atom and an electron-deficient hydrogen atom).
How is the tertiary structure formed?
formed by the 3D folding of the secondary structure into a complex shape.
What determines the shape of a tertiary structure?
the type of bonding present, such as hydrogen bonding, ionic bonding and disulphide bridges
What is the quaternary structure?
The 3D arrangement of more than one polypeptide.
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