User:Eric Martz/Ramachandran Principle Quiz

1 How many bonded atoms are required to constitute a dihedral (torsion) angle, such as phi or psi?

	None
	1
	2
	3
	4
	5

2 The number of phi and psi angles in an isolated amino acid (not in a polypeptide chain) is:

	None
	1
	2
	3
	4
	5

3 The number of atoms held into a geometric plane by a peptide bond is:

	3
	4
	5
	6
	7
	8

Questions below may have more than one correct answer.

4 Phi and psi angles directly determine

	Primary structure.
	Secondary structure.
	Tertiary structure.
	Quaternary structure.

5 Alpha helices are compatible with

	All possible phi-psi angle combinations.
	A limited range of phi-psi angle combinations.
	A limited range of phi angles with all possible psi angles.
	A limited range of psi angles with all possible phi angles.

6 Common secondary structures are energetically favored because

	They optimize main-chain hydrogen bonds.
	They represent all possible conformations.
	They maximize clashes between atoms.
	They minimize clashes between atoms.

7 Overlap of van der Waals radii

	Between two non-bonded atoms is called a clash.
	Between two covalently bonded atoms is called a clash.
	Occurring between two non-bonded atoms in a molecular model signifies an energetically favorable interaction.
	Is physically impossible between two non-bonded real atoms.

8 xxx

	They optimize main-chain hydrogen bonds.
	They represent all possible conformations.
	They maximize clashes between atoms.
	They minimize clashes between atoms.

9

	They optimize main-chain hydrogen bonds.
	They represent all possible conformations.
	They maximize clashes between atoms.
	They minimize clashes between atoms.