Template Strand vs. Coding Strand: Key DNA Differences Explained
The Template Strand is the DNA sequence that RNA polymerase “reads” to make a complementary RNA transcript; the Coding Strand is the matching, non-transcribed strand that looks like the eventual mRNA (just swap T for U).
Students swap them because textbooks draw genes left-to-right yet genes can sit on either DNA strand; one glance at a double-helix diagram and it’s easy to assume “top = template.”
Key Differences
Template: 3’→5′, serves as mold, sequence is antisense. Coding: 5’→3′, identical in order to mRNA (T→U), never copied directly.
Examples and Daily Life
In a PCR primer design app, you paste the Coding Strand; the program flips it to create primers that bind the Template Strand during amplification.
Which one ends up in the RNA?
The Template Strand guides synthesis; only its complement becomes RNA.
Can a gene have its template on the “bottom” strand?
Yes—genomes are littered with genes reading in opposite directions.