27 Questions
Which field of information technology uses computers and computer programs to facilitate the collection, storage, analysis, and manipulation of large quantities of chemical data?
Chemoinformatics
What are the central concepts behind chemoinformatics?
Structure-activity relationships (QSAR) and compound property prediction (QSPR)
How are chemical structures usually stored in a computer?
As molecular graphs
Which of the following is NOT a type of variation seen in Markush structures?
Sequence variation
In the three stages of the search system, which stage involves matching fragments against homologous series identifiers?
Search based on a reduced graph representation
What is the purpose of fragment-screening in the search system?
To identify common fragments in specific structures
What is the recommended tool for generating the SMILES string and InChI representation of compounds in Lagundi?
ChemDraw
Which algorithm is an extension of the Morgan algorithm and incorporates stereochemistry information?
The SEMA method
What is the initial connectivity value assigned to each atom in the Morgan algorithm?
The number of connected atoms
Which algorithm uses similar principles to the Morgan algorithm to produce a canonical ordering of atoms in a graph?
The CANGEN algorithm
What is the purpose of a hash key in structure searching?
To retrieve information about a structure directly from a database
Which of the following is true about a molecular graph?
The nodes correspond to the atoms and the edges correspond to the bonds.
What does a subgraph represent in a graph?
A graph that is a subset of another graph.
What is true about a tree in graph theory?
It has a starting point called the root node.
What is true about isomorphic graphs?
They have the same number of nodes and edges.
Which algorithm uses adjacency matrices to represent the molecular graphs of the query substructure and the molecule?
Ullmann algorithm
What value is assigned to elements (i, j) and (j, i) of the adjacency matrix if atoms i and j are bonded?
1
What is the aim of finding matching matrices in subgraph isomorphism?
To find matching matrices with each row containing just one element '1' and each column containing only one element '1'
What is the purpose of the Smallest Set of Smallest Rings (SSSR) in chemistry?
To identify the set of rings from which all others in the molecular graph can be constructed
Which algorithm is not used to generate a unique SMILES string for each molecule?
Canonical SMILES algorithm
What is the purpose of substructure searching?
To identify all molecules in the database that contain a specified substructure
What is the purpose of the bitstring representation in screening methods?
To rapidly eliminate molecules that cannot possibly match the substructure query
What does a hash key represent in structure searching?
The physical location on the computer disk where the data associated with a structure is stored
What is the purpose of the Smallest Set of Smallest Rings (SSSR) in chemistry?
To identify the rings containing the fewest atoms
What is the purpose of a connection table in chemoinformatics?
To communicate the molecular graph to and from the computer.
What is the purpose of a canonical representation in chemoinformatics?
To establish whether two connection tables or two SMILES strings represent the same chemical structure.
Which of the following is NOT a type of variation seen in Markush structures?
Stereochemistry variation
Test your knowledge of the Morgan algorithm and SEMA method used for determining a canonical order of atoms in this quiz. Learn about connectivity values and how stereochemistry information is incorporated.
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