Welcome to the Support Communities!
The ability to choose which Mail account or Mailbox you want to look at has not changed.
The image below is from the iPhone User Guide.
If you only want to look at your work email, you can tap on Mailboxes, then choose the inbox of that email account.
You can also scroll down and choose the account itself if you need to see the Sent messages, Drafts or Trash for that account.
Here is a link to the iPhone User Guide for iOS 7:
I don't know which iPhone you have, but this new information on our website will give you some tips about the new iOS (there are also guides for the 5c and the 4s):
I hope this information helps!