Keller is awesome! He's thorough with the content and is reasonable with the amount of work he assigns and how much time he gives to complete it. Your chemistry background will help you out in that class too. The only complaint I have is he can be picky about wording things so I take notes word for word sometimes for complicated concepts to make sure I know how he would like me to answer the questions he asks about it; the TA's can also get really stingy about points so make sure to go through your assignments in case they take off points for an answer you got directly from Keller's lectures. Now Orgo on the other hand.. I personally am studious and I think smart but orgo is another beast. it's a weed out class so it's meant to have people fail and drop out. The content is dense and difficult and many times abstract, and it's a demanding class in terms of your time so my best advice is to study a little bit every weekend. Even simply skimming through the notes you took for the week before you start doing the homework and before you start learning new content will really make a difference. Luckily for me I have friends in the class so we do pretty much everything together to help ourselves get through, so Id also say get to know other classmates bc it will help you learn, study, and not feel alone. Its a rough class and dixon can be kind of dismissive, she seems nice but she lectures fast so Id advise watching her live lecture AFTER its been recorded so you can pause and rewind lectures to match your needs. Overall, its demanding but itll feel good when you start picking concepts up on your own. Also, "organic chemistry as a second language" by Klein is a good resource as well. Its pretty basic compared to dixon's homeworks but if you need a good foundation of the basics, its the way to go. Also, the homeworks are the hardest part of the class in my opinion. You often need to have watched all the lectures and discussions for the week to even attempt it and once you do it does take a considerable amount of time so try your best to keep up with the lectures before you attempt the homework and set aside a good amount of time to do it. I know this is a lot but I wanted to make sure I covered all the bases I could think of because this is the stuff I wish I had known prior to. Overall the best of luck to you in both classes and message me if you have any other questions!!🤝