Please explain Act III scene one from "The Merchant of Venice."

In "The Merchant of Venice," Antonio has undertaken the repayment of a "bond" to Shylock and has accepted a forfeit of a pound of his "fair flesh" (I.iii. 145) if he does not repay the money in time. In Act III, Antonio's ships are rumored to have been "wrecked" and Solanio and Salerio discuss the possible disastrous outcome for "the good Antonio."

Shylock's daughter Jessica has secretly left her father's house and Shylock now approaches the two men and accuses them of helping her "rebel." When Shylock refers to her as his "flesh and blood," Salerio suggests that Jessica is nothing like her father. He makes comparisons between "jet and ivory..red wine and Rhenish."  

The subject then changes back to Antonio's apparently doomed ships. Shylock says that Antonio must learn his lesson for having mocked Shylock's business in the past and he now expects Antonio to pay his bond. However, Salerio inquires as to the point of taking "his flesh." Shylock admits that the only real purpose is to "feed my revenge." Antonio has never respected Shylock and his reasons are based only on the fact that Shylock is a Jew. Shylock reminds the men that Jews are normal people with "hands, organs, dimensions, senses...;" in other words, they are all the same. Jews bleed just like Christians and Shylock now wants his revenge because his "nation" has been wronged. Shylock explains that it is the very lessons or "villainy" that "Christian example" has taught that ensures that he will "better the instruction," meaning that he will do the Christians the same as they have done to him, and worse.

Salerio and Salanio leave to speak to Antonio and Tubal, a fellow Jew, comes to speak with Shylock about Shylock's daughter. Shylock talks about the things that are missing from his home- including a diamond and two thousand ducats. Shylock is taking it hard and is counting the cost to himself but Tubal reminds him that others also have bad luck. On the mention of Antonio, Shylock is pleased because it seems that his ships have been wrecked. The conversation jumps between the good news of Antonio's problems and the unfortunate news of Jessica who even stole a precious ring and exchanged it for a "monkey." Shylock is now anxious to apprehend Antonio.