Does My iMac Support Cpu And Or Gpu Upgrades?

About a Year Ago i Bought This iMac off of Ebay for a cheap price. fully working to my suprise, i changed the hard drive to an ssd, and it has currently 4gb of Ram. I’ve seen many videos and guides both on youtube and ifixit of iMacs getting Cpu And/Or Gpu Upgrades. Most memorable to me was the 2007 20” iMac And the Cpu Upgrade. Im currently running MacOS Catalina Patcher on my iMac and it is running good, although i would like to (if possible) to upgrade the Gpu. Any Help Is Appreciated.