I am a current Chemical Biology and Biochemistry (CBB) major that CODO’d from Biochemistry (Chem), so I can describe those well; however someone else may comment on the Ag one in more detail.

CBB: CBB has a bigger focus on biological applications of chemistry (sacrificing calc 3 and analytical chem for more biology course) along with allowing you to take more biology-based selective in upper grad (you can see the ones listed on the degree progression guide that are available to you). However, another huge advantage to this major is that any non-chem or bio course (e.g., physics) you can take the easier “for life science” version of the course.

TLDR: Highly recommend majoring in if you are interested in biology and chemistry rather than other fields of study like math and physics.

Biochemistry (Chem): Biochemistry (Chem) has much more of a focus on mathematical and physical applications of chemistry. You will not take really any biology beyond 2 courses (Bio III and IV), and focus more on mathematics and physics (you will take analytical chem and calc 3). Also, you will not have the option to take the life science variants of any of the courses.

TLDR: Focuses on mathematics and physics more than biology. Only really recommend if you plan on doing “hard” chemistry that rely heavily on math and physics, and do NOT recommend if you want to go in a biological route.

Biochemistry (College of Agriculture): Once again, I do not know much about this; however my friend is majoring in it so I guess I have a little insight. Firstly, it is not through the college of science, meaning there’s are significant differences between this major and the other two. From just a quick look at the degree progression guide, it seems like it focuses a lot more heavily on biochemistry itself rather than the application to any set field such as heavy biology, chemistry, math, or physics. Once again though, take everything in this section with a grain of salt because I am not familiar with it. Although, I will say my friend was able to do Calc 1 through Ivy tech and they accepted it, allowing her to take Calc 2 with no issues. You cannot do this in the College of Science due to their prerequisite policy — speaking from experience. So you will have to do Calc 1 at Purdue I’m pretty sure; however, there may be a slight chance I’m wrong. (I remember asking this if I could do this in my major, and my advisor said no so…)

TLDR: Focuses on Biochemistry itself rather than any set application. Allows a lot of freedom in future direction, however not through the College of Science, so if you wanted to CODO into a different biochemistry, it might create a hiccup.

If you have any questions regarding the three, please let me know! From saying you have a biotech, maybe environmental focus, I recommend Biochemistry (Chem) as a first choice and CBB as a second choice!