In "The Merchant of Venice", what were Shylock’s terms for lending money to Antonio? Why did Antonio so readily agree to the terms?

Shylock tells Antonio that if the three thousand ducats are not repaid in the stated time period, he will be allowed to extract one pound of Antonio's flesh. Antonio readily agrees because he is confident the ships that carry the returns of his investments will be safely into harbor well before the deadline. It is also suggested Antonio agrees in order to prove his superiority to Shylock, who he is in the habit of belittling and criticizing in public. As well, Antonio wishes to help his friend Bassanio by securing the loan for him (so that Bassanio can court Portia), so agrees to the terms so as not to disappoint Bassanio.