Protein Structure and Chemistry Flashcards
Aspartic Acid (Asp)
Polar Charged
Hydrophilic
Glutamic Acid (Glu)
Polar Charged
Hydrophilic
Lysine (Lys)
Polar Charged
Hydrophilic
Arginine (Arg)
Polar Charged
Hydrophilic
Amino Acid Stereoisomers
Amino acids that are made up of the same atoms and bonded by the same sequence of bonds, but have different 3-D structures
Histidine (His)
Polar Charged
Hydrophilic
Serine (Ser)
Polar Uncharged
Hydrophilic
Threonine (Thr)
Polar Uncharged
Hydrophilic
Glutamine (Gln)
Polar Uncharged
Hydrophilic
Asparagine (Asn)
Polar Uncharged
Hydrophilic
Tyrosine (Tyr)
Polar Uncharged
Hydrophilic
Alanine (Ala)
Nonpolar
Hydrophobic
Valine (Val)
Nonpolar
Hydrophobic
Leucine (Leu)
Nonpolar
Hydrophobic
alpha-helix
a secondary structure in which the amino acid chain is arranged in a right-handed spiral
Every backbone N−H group hydrogen bonds to the backbone C=O group located four residues earlier along the protein sequence
Isoleucine (Ile)
Nonpolar
Hydrophobic
Methionine (Met)
Nonpolar
Hydrophobic
Phenylalanine (Phe)
Nonpolar
Hydrophobic
Tryptophan (Trp)
Nonpolar
Hydrophobic
Glycine (Gly)
Side chain has only hydrogen atoms, can be hydrophilic or hydrophobic (non-chiral molecule)
Cysteine (Cys)
Side chain in Polar Uncharged, but can form a covalent bond with another cysteine to form a disulfide link
Proline (Pro)
Hydrophobic, but creates kinks in polypeptide chains that disrupt secondary structure
Beta-pleated sheet
Occurs in globular proteins when two or more segments of a polypeptide chain line up next to each other, forming a sheet-like structure held together by hydrogen bonds
Every peptide bond is hydrogen bonded to a neighboring peptide bond
What are the second structure levels of proteins
alpha-helix
beta-sheet
What are the tertiary structures
domain
protein subunit (monomer)
What is the quaternary structure
protein molecule (dimer)
What are the levels of protein stucture in order
alpha-helix and beta-sheet —> domain —> protein subunit (monomer) —> protein molecule (dimer)
