Creating a metabolic pathway in Neo4j

Question

I am attempting to create the glycolytic pathway shown in the image at the bottom of this question, in Neo4j, using these data:

glycolysis_bioentities.csv

Answer 1

@cybersam's answer is excellent, providing the most elegant solution (once again: thank you!) -- please upvote that accepted answer.

Since this question/answer/topic is likely to be of interest to others, I wanted to mention that my code (based on this SO thread, How to specify relationship type in CSV?, and modified per the hints provided by @cybersam) now works, and show the result:

Solution 1 (my original post, updated):

LOAD CSV WITH HEADERS FROM "file:/glycolysis_relations.csv" AS row
MERGE (s:Glycolysis {name:row.source})
MERGE (t:Glycolysis {name:row.target})
FOREACH (x in case row.relation when "substrate_of" then [1] else [] end |
  MERGE (s)-[r:substrate_of]->(t)
)
FOREACH (x in case row.relation when "yields" then [1] else [] end |
  MERGE (s)-[r:yields]->(t)
  );

Solution 2 (cybersam's, updated):

LOAD CSV WITH HEADERS FROM "file:/glycolysis_relations.csv" AS row
MERGE (s:Metabolism:Glycolysis {name: row.source})
MERGE (t:Metabolism:Glycolysis {name: row.target})
WITH s, t, row
  // "Bug" -- additional duplicate relations with each iteration of this statement/script:
  // CALL apoc.create.relationship(s, row.relation, {}, t) YIELD rel
  // Solution: 
  // https://github.com/neo4j-contrib/neo4j-apoc-procedures/issues/271
  // https://stackoverflow.com/questions/47808421/neo4j-load-csv-to-create-dynamic-relationship-types
  CALL apoc.merge.relationship(s, row.relation, {}, {}, t) YIELD rel
RETURN COUNT(*);

Both solutions generate the identical graph, below. :-D