Chemisty HL IA Ideas with relations to Biology/ Animal Science?

[Colourflame]

I need to start getting solid with my IA topic but right now I am just brainstorming ideas and wanting to hear some ideas from peers.

So far I only have around three ideas but are fairly common and perhaps not HL worthy:

1) Calcium content in different types of milk ( not sure how to do this one but interested, wondering if I should use the milk of different animals or different processes and procedures)

2) Enzyme and substrate relationship on how changing the amount of substrate would affect the enzyme activity and perhaps the pH as well? ( Biological catalyst, a bit worried that this is too biology, thinking about using catalase and hydrogen peroxide but afraid that it is too common and also would like to explore different enzymes as well)

3) Best material for cooling pack (quite random really...)

I don't really have a lot of confidence in myself and due to previous issues, I have stuff in my chemistry academics to catch up on and find it different to concentrate and understand but I'm willing to learn and work hard. 

Please do suggest different Chem IA topics as well! I would love to hear them and perhaps find one that I really like.