"It is not words that shakes me thus. Pish! Noses, ears, and lips--is't possible? Confess--handkerchief--O, devil! [He falls into a trance.]" (Shakespeare 4.1.51-54). "My medicine, work!" (4.1.55-56).
Peripeteia
"O, damn her, damnher!...furnish me with some swift means of death for the fair devil" (3.4.541-544)
I am your own forever" (3.4.546)
Hubris
"When you shall these unlucky deeds relate,speak of me as I am" (5.2.401-402)
In this moment in Act 4 Sc. 1, Othello shows how his hamartia will lead to the downfall of his character. He has fatal flaws such as jealousy, insecurity, and naivety, and his outburst and "trance" of anger shows how much those emotions of easily controlled him and how his hamartia would led to his ruin.
Ate
"It is too late. [He smothers her.]" (5.2.105-106)
In this scene (Act 3, scene 4), Othello shows a turning point when he completely believes Iago and vows to kill Desdemona. He is essentially turning to the "evil side" when he chooses hatred over trust and plans to murder his wife.
Anagnorisis
O, O, O! "Precious villain!" (5.2.282)
This scene at the very end of the play in act 5 shows Othello's hubris in his last words. He gives a speech about his guilt and analysis of character, trying to defend his reputation and character. This shows his arrogance because his final speech was to salvage his own reputation and pride.
Nemesis
"...to die upon a kiss..."(5.2.521)
In Act 5 scene 2, Othello kills Desdemona. This is the action that leads to his downfall because it is the irreversible destruction of his marriage, reputation, and (later) life.
This is a depiction of the anagnorisis in Act 5 scene 2 where Othello discovers the reality of what happened and the true nature of Iago's character and plan. This critical realization occurs after Emilia uncovers the deception and Othello runs at Iago (just as Iago stabs Emilia).
This is a depiction of the hero's nemesis. In this case, it is Othello at the end of Act 5, dying next to Desdemona after stabbing himself, the inescapable justice for killing Desdemona.