Amino Acid & Protein Structure Flashcards
What are proteins are present in enamel and what is their function?
Amelogenins
Enamelins
Framework for mineralisation
What are proteins are present in dentin? (3)
Collagen
Glycoproteins
Proteoglycans
What are proteins are present in cementum? (2)
Collagen
Glycoproteins
What determines the structure of a protein?
DNA sequence
Describe and explain the structure of a protein formed by spontaneous folding up of a linear amino acid chain (side chains).
Non polar side chains = hydrophobic = core region
Polar side chains = hydrophilic = on outside of molecule (forms H-bonds with water)
What amino acid enantiomer is found in nature?
L
Which amino acid does not display optical isomerism?
Glycine
What bond links two amino acids?
Peptide bond
Which amino acid can be both hydrophilic and hydrophobic?
Tyrosine
What is special about cysteine?
Able to form disulfide bonds (cystine)
What is special about proline?
Side chain is continuous with alpha amino group (constrains protein structure)
Why do we draw the amino group on the left hand side (start from N-terminal)?
Reflects process of translation
Give three features of the peptide bond
Shorter than expected
Rigid (no rotation around bond)
Trans arrangement
What are the partial charges in the amide link?
Partial negative charge on oxygen
Partial positive charge on nitrogen
What type of reaction is the formation of a disulphide bridge?
Oxidation
