how does Salario and Solanio's conversation about Antonio at the beginning of Act One provide initial exposition of Antonio's character and conflict ?

Antonio seems like a generous man. He wants to help his friend Bassanio, he is perhaps in love with him, even if it means facilitating Bassanio's marriage to Portia. Antonio is a businessman but perhaps not a very good one. He promises money he does not yet have at a most terrible penalty (his flesh) should he not be able to deliver on his loan.