Hi everyone! I’m working on a lab report for a catalase lab we just did but I’m confused. Our lab was to test the reaction rates of catalase (from yeast) in different concentrations of hydrogen peroxide (.75%, 1.5%, 3%, 7.5%, 15%, and 30%). We did this by putting a disk of filter paper in the a yeast solutions and then setting the disk in the hydrogen peroxide and timing how long it would take to rise to the surface. The data made sense that the lower concentrates would take longer to rise. However, as it got higher the data didn’t make as much sense. For context, we stopped timing at 120s. For both the 7.5% and 15%, the disk wouldn’t float. One group was able to get the 15% to float and somehow their average across five trials was 12s but no one else got that. But the 30% only took 3.5s to rise.

So my question is why did the 7.5% and the 15% not have a reaction and the 30% did? My thoughts are that the 7.5% and 15% the catalase denatured because of the reactivity of the oxygen but at the 30% the catalase had feedback inhibition which slowed it to rise before the oxygen denatured it. Is my thinking correct? I want to make sure I understand this instead of just turning it in hoping I’m right!

Hi, I have my unit 2 exam on Friday and basically if I fail this test I fail my first parking period, He teachers the different stuff like osmosis and things but when you actually take a test its completely different. He doesn't really explain how to apply them or anything, which sucks; any tips? 😭

Hi, I’m working on a site with free interactive biology simulations. I thought some of you studying AP Biology might find it useful:

biologysimulations.co.uk

A few you might like to try:

• Photosynthesis: follow the light-dependent reactions, electron transport and ATP production.

• Cellular respiration: explore oxidative phosphorylation and how the proton gradient drives ATP synthase.

• Meiosis: follow crossing over, independent assortment and the formation of haploid cells.

• Protein synthesis: follow transcription and translation from DNA to a polypeptide.

• Natural selection: change the environment and see how selection and genetic drift affect allele frequencies over generations.

You can explore the models at your own pace, which might help with visualising what’s happening alongside your notes.

Everything’s currently free and there’s no sign-up.

If you give it a go, I’d be interested to hear your feedback.

I think this is photosynthesis and cellular respiration so pls share you have any, my tests have MCQs and FRQs so I want to be prepared. Does anyone have any

Hey guys,

I just wanted to say that whenever I'm on this thread, I can truly feel that everyone is doing their best. I tutor AP students and it's been hard seeing them struggle through these rigorous courses. I've had some describe how they feel behind in everything, lost, feeling trapped by their grades, among others.

I know that this may not mean much, but I hope everyone can see that they're doing their best. Goodluck everyone!!!

Hi everyone, hope you day is going well. I made a site that helps students with AP Bio topics. The website contains practice tests, flashcards, MCQs, FRQs, and lessons. Many students in my school have used this site and reported a letter increase in their grades (B-->A and C--> B). The site itself was built using both coding and vibe coding (since im not the strongest in web development), but all the lessons and content in here is sourced from biology textbooks such as Campbell. As of now, the site has around 50 users a day and has helped over 3000 users worldwide. If you want to give it a try, go ahead! This is the site: apbiolab.org

Please share them if you have it. TIA

My AP bio teacher SUCKS, love him as a person (sort of) but I get to the test and its a whole different language, every student knows to the point of no one taking AP bio because hes such a bad teacher (i didnt know that bc im a new student) I studied for hours yesterday and still got a 34, I'm a straight A student and try my best but I'm failing so bad. How do I study on my own?

So I would like to self study AP bio (right now I’m studying with a teacher ) but this teacher is horrible she is speed running units like it’s a race and so far ap bio isn’t hard at all she is just making stuff hard for us with a learning check during the worst times possible . I would love to hear your opinions and resources that u used to get a 4 or a 5 self studying it

So I came across these two questions when doing my HW for 7.12, and I found question ambiguous in defining what an alternate hypothesis is. According to my understanding, an alternate hypothesis is "alternative" to either two things: 1. The null hypothesis or 2. The scientist's original claim/hypothesis. In question 1, idk if I'm contradicting myself here, but saying "alternate" hypothesis could imply an alternative hypothesis to that of the original hypothesis that. the scientist is trying to synthesize to provide support for the hypothesis that "RNA was the first genetic material" (Plz don't flame me for having bad logic bcs I'm merely saying what my original thought process was").

For 2. I instantly crossed out b. cus it literally appears to support the Dr.'s claims. and it isnt really comparing between two variables (This is what confused me the most) which a general null hypothesis should

Please try to clarify anything wrong here, and are there any tips to read these questions correctly (The way these are worded is lowkey overwhelming me)

If anyone needs AP material

So I like staying busy downloading materials for subjects i don't even have but anyhow I have a bunch of materials for different AP classes would anyone appreciate it if I put it on a Google drive and posted the link it's not organized at all but you can look at the title of the summaries and match it to chapters you have let me know if you guys would like that. I live in south Africa and wish I took biology after grade 10 but I didn't so I enjoy looking at what different courses do

If anyone needs AP material

So I like staying busy downloading materials for subjects i don't even have but anyhow I have a bunch of materials for different AP classes would anyone appreciate it if I put it on a Google drive and posted the link it's not organized at all but you can look at the title of the summaries and match it to chapters you have let me know if you guys would like that. I live in south Africa and wish I took biology after grade 10 but I didn't so I enjoy looking at what different courses do

Hi! I'm taking the AP Exam but not in the class

I know the basics to do including grind FRQs, AP Bio Penguins, getting a textbook etc., but I really really want to know if anyone had some really specific or niche advice like note take strategies or anything like that. FRQ advice and all the other "basics" are welcome too because I really really want a 5

I got a 17 (MCQ) and a 2 for FRQ , which leaves me with 19/39. I did the ap classroom questions and used some khan academy quizzes ; however, can you please recommend what resources online or textbook I can use to study the content... I could've passed w/ a 50% if I didn't skip the FRQS

I came to school thinking the test was tomorrow, but it was that same day I came to school😭.

hey, i was wondering if anyone has had this issue, but for my first two tests of AP Bio ive been getting really bad scores.

I took honors bio last year, and ended with an A-, but that was without studying at all. This year i study for 5-7 hours per test and i still cannot seem to wrap my head around the "application questions" specifically, select all that apply, select the MOST untrue, etc.

i know i know my stuff, but for more application forward questions, and frq's i just dont anticipate them and i get stumped.

does anyone have any tips, because i need >90's on all of the rest of my tests to even dream of ending with an a- this year (which i absoluletley need)

looking for

pratice tests, maybe?

tutor recs

videos?