Every denomination has a "pope." Every denomination, no matter how large or small, has someone who occupies a prime position of authority. The Catholic Church has a Pope. In fact, she has an unbroken succession of pontiffs stretching all the way back to St. Peter, her first Pope.
Just as the patriarchs Abram and Jacob received new names to signify their special mission, so Jesus gives the name of Cephas (or Peter), which means 'Rock,' to Simon. This name change clearly illustrates to Jesus' followers that Peter occupies a place of primacy among the apostles.
Jesus gives Peter the keys of the kingdom of heaven (Mt 16:19). The significance of this action is rooted in Isaiah in the passage where Eliakim receives the keys of the office of prime minister held by Shebna. Isaiah prophesies God's word to Eliakim: "I will place the key of the house of David on his shoulder; when he opens, no one shall shut, when he shuts, no one shall open" (Is 22:22). Peter is also commissioned with the power to bind and loose.
Doubters have tried for centuries to deny that Jesus founded a visible Church under the leadership of St. Peter. However, an honest study of Scripture and history causes their best efforts to crumble like a house built on sand (see Mt 7:26-27).