Peptides and Proteins Flashcards
What type of bonds are planar?
peptide bonds
Where do 20 different possible side chains protrude from?
the repeating backbone of a protein
What are the bonds listed from strongest to weakest?
ionic-> covalent-> disulfide-> salt-> hydrogen-> electrostatic-> Van der Waals
What are the characteristics of a primary structure?
- sequence of covalent bonds
- very stable
- amino acid sequence contains info. required for protein building
What structure determines the folded structure of a protein?
primary structure
What are the characteristics of the secondary structure?
- reverse turn (beta turn)
- alpha-helix
- alpha-helical interactions
What bonds are associated with each structure?
- covalent-> primary & tertiary
- hydrogen-> secondary
- noncovalent interaction-> quarternary
In a beta strand of a secondary structure, where are the side chains located?
above and below the plane strand
What is the difference between a parallel and antiparallel beta sheet?
- parallel: strands run in the SAME direction; H bonds connect an amino acid to 2 amino acids on adjacent strand (1:2 bond)
- antiparallel: strands run in OPPOSITE direction; H bonds connect 1 amino acid to 1 amino acid on adjacent strand (1:1 bond)
Which beta sheet stabilizes the secondary structure?
antiparallel
Myoglobin/aquaporins have what on the inside and what on the outside?
hydrophilic on the inside and hydrophobic on the outside
Myoglobin is in what structure?
tertiary
In the tertiary structure of a protein, where are the hydrophobic and charged (hydrophilic) amino acids found?
hydrophobic are found on the inside and charged are found on protein surface
What is the role of beta-mercaptoethanol in denaturation?
responsible for reducing disulfide bonds
What is the role of urea in denaturation?
breaks down H bonds, Van der Waals, and salt bridges
