How do I edit the value of an specific SharePoint list column and row

[plotwistking]

I'm very new to PowerApps so my terminology sucks, so bear with me.

Let's say I have a SharePoint list I'm working with in PowerApps.

I generate an App based on this list. In it, I'm able to select one of the above rows, if I do, I'll enter a new screen that lists all its details, which also contains a button to edit it, and a button to delete it.

Let's say I select the ID 1 row.

I'm creating a new button that's almost a copy-paste of the delete button which will be the "Lock" button. For now, all I want it to do is edit the Column "Lock" of the selected row to "Yes". What should my code look like? I know 

BrowseGallery1.Selected

 plays a role here, through I'm not exactly sure how to work with it. Thanks for reading.

[plotwistking · Accepted solution]

Learning the difference between Record and Gallery helped tremendously. Here's the solution I found:

Patch(LIST, BrowseGallery1.Selected, {Lock: "Yes"});