Apple app update question

[Jericho14]

I originally set up my profile on the Apple Store many years ago.
Since then, Ive changed my email address and password several times. Yet even though Ive gone into Apple Store preferences and changed my profile to the current settings, it still, it seems by default, brings up a box with my original email address and PW every time I attempt to update Apple Apps. Today, it allowed me to install a security update for IOS, but won't let me update programs like iPhoto, and others as well.
I have a late 2009 iMac, IOS 10.10.1 Yosemite, Memory 12 meg, and a 1 Tbyte HDD.
Any suggestions?

 

[Apple_Robert]

Whatever apps, music, and movies you previously purchased under your different email Apple accounts are locked to those specific accounts, and cannot be transferred to your current Apple email account.

What you can try doing, is authorizing any music or movies in those previous accounts to be played in your new account.

 

[Jericho14]

Whatever apps, music, and movies you previously purchased under your different email Apple accounts are locked to those specific accounts, and cannot be transferred to your current Apple email account.

What you can try doing, is authorizing any music or movies in those previous accounts to be played in your new account.

Why would they do something so stupid?
How do I authorize that?