Mertesacker is pleased that the Emirates plays host to the second leg.
"We hope that [playing] the first game away is a bit of an advantage for us," he said.
"We have to concentrate on that game.
"[Playing] away in Istanbul is always special, the fans are passionate and we have to cope with that and realise that we have a chance to qualify for the Champions League.
"We did a lot in the last season, especially in the last 10 games to get the chance to get [in] the qualifiers. We have to focus on that."
For the big stories and the banter follow us on Twitter: @tribalfootball