amino acids and proteins Flashcards
What are primary structures of amino acids and what problems can occur in them
Primary structures are made from sequence of amino acids, improper amino acid sequence can cause improper folding or loss of protein function
What is the peptide bond and how does it connect
Peptide bond covalently connects the two amino acids. The link is from the alpha carboxyl group of one amino acid to the alpha amino group of another
What are peptide bonds resistant to, and how can they be broken
Peptide bonds are resistant to heating and high concentration of urea, which denature proteins. It is shown to strong acid or base at high temperatures to break the bond
What conformation does the peptide bonds take
Trans configuration
Why is trans configuration of peptide bond important
It allows for less steric interference in the R groups
What bonds stabilizes the secondary structure
Hydrogen bond
How are primary and secondary amino acid sequences different
Primary is the sequence of amino acids, secondary is the arrangement of amino acids that shows the localized shape of the protein other than 3D arrangement
How do alpha helix hydrogen bonds connect
They connect from the carbonyl oxygen with the peptide bond to the amide hydrogen of the backbone
What are the side chain amino acids that can break Alpha helix
proline, as the secondary amino group is not compatible and forms a kink, Glycine has hydrogen in the R group, any bulky or charged R groups
What is pleating
Pleating is the bonding that is formed in the beta pleated sheets, that is caused from successive alpha carbons being slightly above or below the plane
What are motifs
Supersecondary protiens that are globular made from secondary structures. They mainly form the core of the molecule. They are connected by loops at the surface
How are motifs formed
Motifs form from side chains from adjacent secondary structures that link together
Domains
Fundamental functional and 3D structural unit of polypeptides for tertiary structures
What enzyme breaks and forms disulfide bonds during folding
Protein disulfide isomerase
Intrinsically disordered proteins
Biologically active proteins that lack stable tertiary structure
