Main Entry: up·stream

Pronunciation: \ˈəp-ˈstrēm\

Function: adverb or adjective

: in a direction along a molecule of DNA or RNA opposite to that in which transcription and translation take place and toward the end having a phosphate group attached to the position labeled 5′ in the terminal nucleotide <a small coding sequence is located just upstream from each…gene—J. N. Goldman et al>—compare downstream