Apps updated in iTunes don't update on my iOS devices when Syncing.

I normally use iTunes to "Update All Apps" and then expect the updates to transfer to my iPhone and iPad when I connect them to Sync. However, the updates are not getting sent to the IOS devices. Any suggestions? I'm using a new iMac w/OS X Yosemite and iPhone 6 Plus and iPad 2. iTunes version 12.0.1.26.