More than 5,000 bills and joint resolutions have been introduced so far during the 82nd Legislature; many of these bills propose adding to, amending or repealing existing laws. 
The Index to Sections Affected, produced by the Legislative Reference Library, can help you track how proposed legislation would affect existing laws. 
Let's say you are searching for bills affecting podiatrists, governed by Occupations Code chapter 202. Simply select Occupations Code from the dropdown menu, and enter 202 in the Section / Legislature box to see a list of all introduced bills which would affect this chapter.
You can also search for changes to laws which have not been codified and are only found in the session laws, if you know the session and chapter of the law. 
For example, the Bexar Metropolitan Water District was created by Chapter 306, Acts of the 49th Legislature, Regular Session, 1945. To find legislation proposing changes to the district, select the "Session Laws" from the dropdown Code menu, then enter the number 49 in the Section / Legislature box.
You can search entries from the 76th Legislature through the 82nd by code and section. Library staff indexes each version of each bill, so you can see how legislation evolves over the course of a session. Use the Status options to specify which versions to search. If a bill is vetoed, the veto will be noted on all entries associated with the bill.
After a session, it may be some time before print and online statutes are updated. Use the Index to Sections Affected to search for bills with the status "Enrolled" to determine whether laws you are researching were amended by any passed bills.