In act 1 of Romeo and Juliet, what are the iambic meters/iambic pentameter, and why are they there?

There are
already a lot of helpful answers about this question going over what iambic pentameter is and
how Shakespeare uses it generally. Here is one specific example of Shakespeare using meter to
structure and manipulate the text, that might put meter into better context. It concerns the
first wordsspeak to each other until they kiss, towards the end of act 1. Here is the
conversation in its entirety:

[To ]
If I profane with my unworthiest hand

This holy shrine, the gentle fine is this:

My lips, two blushing pilgrims, ready stand

To smooth that rough touch with a tender
kiss.

JULIET

Good pilgrim, you do wrong your hand too
much,

Which mannerly devotion shows in
this;

For saints have hands that
pilgrims' hands do touch,

And palm to
palm is holy palmers' kiss.

ROMEO

Have not saints lips,
and holy palmers too?

JULIET

Ay, pilgrim, lips that they must use in
prayer.

ROMEO

O, then, dear saint, let lips do what hands
do;

They pray, grant thou, lest faith
turn to despair.

JULIET