User:Eric Martz/Hemoglobin Quiz
From Proteopedia
(Difference between revisions)
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||[[Image:Phi-angle.png|150px|right]]The phi [http://biomodel.uah.es/model5/prot/diedros_en.htm dihedral (torsion) angle] is defined by (1) the carboxy carbon from the previous amino acid; (2) N in the amino acid containing the phi bond; (3) C<sub>α</sub> in the amino acid containing the phi bond; and (4) the carboxy carbon of the amino acid containing the phi bond. | ||[[Image:Phi-angle.png|150px|right]]The phi [http://biomodel.uah.es/model5/prot/diedros_en.htm dihedral (torsion) angle] is defined by (1) the carboxy carbon from the previous amino acid; (2) N in the amino acid containing the phi bond; (3) C<sub>α</sub> in the amino acid containing the phi bond; and (4) the carboxy carbon of the amino acid containing the phi bond. | ||
- | {The number of phi and psi angles in an isolated amino acid (not in a polypeptide chain) is: | ||
- | |type="()"} | ||
- | + None | ||
- | - 1 | ||
- | - 2 | ||
- | - 3 | ||
- | - 4 | ||
- | - 5 | ||
- | ||The phi angle involves the carboxy carbon of the previous amino acid in a polypeptide chain. The psi angle involves the N of the subsequent amino acid. Therefore an isolated single amino acid has neither phi nor psi angles. | ||
- | |||
- | {The number of atoms held into a geometric plane by a peptide bond is: | ||
- | |type="()"} | ||
- | - 3 | ||
- | - 4 | ||
- | - 5 | ||
- | + 6 | ||
- | - 7 | ||
- | - 8 | ||
- | ||[[Image:Peptide-bond-plane-6-atoms.png|150px]] | ||
{'''Questions below may have <font color="red">more than one</font> correct answer.'''} | {'''Questions below may have <font color="red">more than one</font> correct answer.'''} | ||
- | |||
- | {The peptide bond is unable to rotate because | ||
- | |type="[]"} | ||
- | - It is a covalent bond. | ||
- | - It is a non-covalent bond. | ||
- | - Rotation would cause clashes. | ||
- | + It is a partially double bond. | ||
{Phi and psi angles directly determine | {Phi and psi angles directly determine | ||
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- Quaternary structure. | - Quaternary structure. | ||
||See [[Protein primary, secondary, tertiary and quaternary structure]]. | ||See [[Protein primary, secondary, tertiary and quaternary structure]]. | ||
- | |||
- | {Alpha helices are compatible with | ||
- | |type="[]"} | ||
- | - 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. | ||
- | ||See [http://bioinformatics.org/molvis/phipsi/index.htm#plot Ramachandran Plot]. | ||
- | |||
- | {Common secondary structures are energetically favored because | ||
- | |type="[]"} | ||
- | + They optimize main-chain hydrogen bonds. | ||
- | - They represent all possible conformations. | ||
- | - They maximize clashes between atoms. | ||
- | + They minimize clashes between atoms. | ||
- | |||
- | {Overlap of [https://en.wikipedia.org/wiki/Van_der_Waals_radius van der Waals radii] | ||
- | |type="[]"} | ||
- | + 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. | ||
- | |||
- | {In a Ramachandran plot, the dots cluster | ||
- | |type="[]"} | ||
- | - Where clashes occur. | ||
- | + Where clashes do not occur. | ||
- | + Where alpha helices occur. | ||
- | + Where beta strands occur. | ||
- | - Where alpha helices, beta strands, and turns do not occur. | ||
- | + Where the phi and psi angles are energetically favorable. | ||
</quiz> | </quiz> |
Revision as of 19:15, 15 September 2018
The quiz below is offered to accompany the interactive tutorial Hemoglobin Molecular Structure.