Proteins Flashcards
What is the monomer of proteins?
Amino acids
What is the strucutre of an amino acid? (draw and label)
Amino group on the left, R-C-H, carboxy group on the left
What are the three main types of amino acids?
Nonpolar, polar, charged
Draw a protein diomer
NH3+ - C=O (peptide bond) - NH - RCH - COO-
+H2O
What creates the secondary strucutres of proteins?
H-bonds between the peptide chains
What are the two types of secondary strucutres
Alpha helix and beta sheet
How long is one turn in the alpha helix structure? Which amino acids are bounded?
3.6 amino acids. Amino acids 1 and 4 are bounded by the H-bonds. (entire strucutre doesn’t fold)
Which one is the special amino acid? Why is it particular?
Proline, only one to make ring strucutre. Does not fit in either alpha helix or beta sheet (no H at N), no freedom of rotation, can only be at the ends.
What mediates tertiary stucutre? What forces/interactions are in play?
Side chains: H-bonds, hydrophobic interactions, Van der Waals, disulfide, ionic
Explain disulfide brigdes
Have to be very close (redox reaction), stabilizes tertiary structure, only covalent bond that can occur
TWhat is the most important aspect of protein folding?
Hydrophobicity. Stretches of hydrophobic amino acids aggregate on the inside fo the protein to avoid interaction with water (self-assembly).
What are coiled coils? How do they occur?
Two alpha helices wrap around each other like a rope. Can be tertiary (protein folds around itself) or quarternary 9two different proteins). The hydrophobic strectehs coil aorund each other, 3.6 amino acids of length per turn
What gives the thertiary sturcutres diversity?
Primary strucutres
Which processes of protein formation require energy? Release energy?
Primary structure (peptide bonds) require energy input, tertiary and quarternary release energy (self assembly)
What is denaturation?
Defolding of the protein due to heat
