Amino Acids And Protein Structure Flashcards
Name some essential amino acids
Histidine
Leucine
Methionine
Phenylalanine
Valine
Tryptophan
Name some conditionally essential amino acids
Arginine
Cysteine
Glutamine
Glycine
Proline
Tyrosine
Name some nonessential amino acids
Alanine
Asparagine
Aspartate
Glutamate
Serine
What are L amino acids
Main substituents on left hand-side
Manufactured in cells and incorporated into proteins
What are D amino acids
Main substituents on right hand side of chirality centre
Some are found in the cell walls of bacteria, but not in all bacterial proteins
When do polar molecules occur
When there us ab electronegativity difference between the bonded atom
When do non-polar molecules occur
When electrons are shared equally between atoms of a diatomic molecule (two molecules joined together) or when polar bonds in a larger molecule cancel each other out
Outline planar
All atoms lie in the same place
Outline zwitterions
Amino acids in solution at neutral pH exist predominantly as dipolar ions
Outline aromatic amino acids
Amino acid that includes an aromatic ring
-phenylalanine
-tryptophan
-tyrosine
Outline the trans configuration of a peptide bond
Two a-carbon atoms are on opposite sides of the peptide bond
Outline the cis configuration of a peptide bond
Groups are on the same side of the peptide bond
What is the typical bond length of a peptide
1.32 A
Outline the ramachandran plot
Recognised that many combinations are forbidden due to steric collisions between atoms
Allowed values can be visualised Ona two-dimensional plot
Outline a helical wheel
Many structural proteins contain amphipathic helices, which consist of hydrophobic, non-polar residues on one side of the helical cylinder and hydrophilic and polar residues on the other side, resulting in a hydrophobic moment
