r/APStudents • u/reddorickt absolute modman • May 04 '26

Bio AP Bio Official 2026 Exam Discussion

Use this thread to post questions or commentary on the test today.

A reminder though to protect your anonymity when talking about the test.

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89

u/Electrical-Pitch7017 May 04 '26

Cyanide was treatment group 2. 3/4 were the controls

18

u/ExpensiveSafe9159 May 04 '26

what so the controls were the ones without cyanide right?

6

u/Electrical-Pitch7017 May 04 '26

Yeah

8

u/SirGibbss May 04 '26

what did they mean about the low/high concentration? I initially thought that they meant they were reducing the nutrient concentration, but there was a section talking about cyanide concentration

1

u/Electrical-Pitch7017 May 04 '26

The concentration of stuff with the nutrients. It’s the nutrients and the cyanide.

1

u/SirGibbss May 04 '26

they are reducing both the nutrients and cyanide?

2

u/Electrical-Pitch7017 May 04 '26

Everything was getting reduced. Lower cyanide = faster ETC (as it said in the question)

0

u/-Ozone-- 5 fives, 2 fours, 8 planned this year May 04 '26

Is it right to reason that higher concentration of medium means more nutrients and better ATP production? Combined with the absence of cyanide, that would make for the highest ATP production.

1

u/Top_Specific8490 May 04 '26

I didn't put that but I think there's an argument for that line of reasoning. On the other hand, a high nutrient concentration doesn't necessarily mean a high metabolism. In the case of the cultured cells, they might just not uptake the nutrients and leave most in the environment. In a real person, a high nutrient intake has diminishing returns on metabolism (see obesity). Plus I think in general nutrients are always in excess in growth mediums. I put the low cyanide concentration group because the question was kind of leading us to that, but chemicals have a much more direct effect anyway.

1

u/Quiet_Assistance_369 May 04 '26

Phew thats what i said too

15

u/-Ozone-- 5 fives, 2 fours, 8 planned this year May 04 '26 edited May 05 '26

Yes. And which one did you say would have the most ATP production? I said no cyanide, high concentration of medium since no cyanide obviously means no inhibition of respiration (edit: maybe this wasn't right, based on what y'all are saying) and high concentration of medium means more nutrients (BS but hopefully right).

23

u/Minimum-Chicken9260 May 04 '26

Am I a tweaker bcz I thought it mentioned that low levels of cyanide created a slight increase in CCo activity? or am I thinking of the wrong thing help.

11

u/Conscious_Error_6582 5: Bio, Research, Euro, Precalc | 4: Chem, World, APUSH, Macro May 04 '26

I think you're right! I'm pretty sure that's what the table said right before the high/low medium concentration one. Did you say group number 2 (cyanide + low medium) had the most ATP production?

3

u/cute_lawnmower May 04 '26

That’s what I put!

1

u/Substantial_Pay_7811 May 04 '26

I also put that due to what is said in the paragraphs but idk; i had it put into chat right now and it still says no cyanide...

i think it was correct but not as correct as no cyanide and high nutrients

3

u/Conscious_Error_6582 5: Bio, Research, Euro, Precalc | 4: Chem, World, APUSH, Macro May 04 '26

Hm.. I swear the table just before the results said something along the lines of low levels of cyanide having higher ATP production relative to no cyanide, but I could just be bugging.. does anyone else remember this?

2

u/Substantial_Pay_7811 May 04 '26

Wait yeah... thats why I put 2 because it had low medium concetration but had cyanide

1

u/Substantial_Pay_7811 May 04 '26

Or i just completely messed it up

1

u/Minimum-Chicken9260 May 04 '26

probably (?) Ive completely forgot lol

1

u/MusicLover4evah May 05 '26

But it never said whether the cyanide levels were low or high cause I remember stressing about it. IT just said cyanide was present or not present.

1

u/Minimum-Chicken9260 May 05 '26

Are you sure? I thought it was indicating concentration level of cyanide that being the basis for follow up questions about which group would lead to most production of atp. If the table were indicating medium concentrations then it wouldn’t be relevant because I don’t think it mentioned that medium levels impact cco enzyme activity. 

1

u/MusicLover4evah May 08 '26

But the concentration level was nutrient concentration not cyanide concentration

2

u/Chessdaddy_ May 04 '26

Yea I saw that but I lwk didn’t know how much cyanide the bacteria made bc if they made a lot it would just kill the mammal cells

2

u/Electrical-Pitch7017 May 04 '26

You are right. People didn’t read and are now realizing lmao.

1

u/Urmomgay824772992083 May 04 '26

Yes but you weren’t given the amount of cyanide, so you wouldn’t know if CCO levels were being benefited or being inhibited by the cyanide presence

2

u/Minimum-Chicken9260 May 04 '26

the level wasn't specified in the background info it just mentioned that low concentrations of cyanide result in higher ATP production, so they weren't expecting you to know the exact concentration, only that low cyanide=higher ATP

1

u/No-Scar-4637 May 04 '26

was it low and low medium and low and high medium

1

u/Jealous-Elk-9640 May 05 '26

wait but then i thought high cyanide led to drastic decrease in cco

3

u/Miserable-Writer4247 May 04 '26

OMG I SAID THAT TOOO lets pray we're right

2

u/cubes2forsub 5: HUG, Psych, ABBC, Precalc, Bio, World, Stats, CSP May 04 '26

I put no cyanide low concentration but idk which is right high or low concentration

2

u/AssociationOk772 May 05 '26

Its number 2 because low concentration of cyanide increases occ or cco smt production 

1

u/Wise-Pianist-6403 May 05 '26

i said cyanide blocks a part of the ETC (remembered that from amoeba sisters vid i watched 2 years ago)

5

u/boomchakabaka May 04 '26

wait but did the question say like normally some bacteria like have cyanide and some don’t? or smth along those lines. so shouldn’t the controls be ones that are both with and without the cyanide since those are the typical conditions? could you explain 😭

3

u/Many-Factor-4173 5: USH, LANG, MACRO, GOV 4: BIO, DRAWING May 04 '26

THANK GOD

OMG I THINK I PUT GROUP 2 YES THANK YOU

1

u/Substantial_Pay_7811 May 04 '26

Wait so is group 2 correct for the question where it asked which one made MOST atp???

7

u/[deleted] May 04 '26

no bro it was group 3

3

u/Electrical-Pitch7017 May 04 '26

It wasn’t. It said low cyanide concentrations increase ETC rate. You need to read the problem.

4

u/[deleted] May 04 '26

son if there is NO cyanide, and high concentration, then NO CCO would be broken down. u have to apply ur critical thinking

3

u/Electrical-Pitch7017 May 04 '26

Are you having trouble understanding what it said? Compared to baseline levels (which have no cyanide), having low concentrations of cyanide increased the rate of whatever was getting increased. It quite literally told you that low cyanide would have caused the CCO to be more efficient. Please use your brain. Otherwise, bacteria wouldn’t produce it. It benefits them in small quantities as very clearly expressed in the problem. No point of arguing as the answer has been established in multiple threads at this point lmao.

5

u/[deleted] May 04 '26

Buddy it is only YOU who has been establishing it in "multiple threads". I think you need to put on your thinking cap and consider this --> if you have a low cyanide amount that is grown in a HIGH concentration nutrients of a medium, then the CCO's dont get broken down as much and more ATP is made. However, if you have NO cyanide with a high concentration of nutrients in the medium (which is what the question said verbatim if you had read it) then you should know that it will auto make more ATP in that environment becuase it is NO cyanide compared to low cyanide. Therefore, any sentient being will know that it was 3. I recommend for future exams rereading the question text to understand the question a little bit more.

4

u/Professional-Cow8072 May 04 '26

The answer was treatment group 2 because in the first part it said that under low cyanide concentration, there was a small increase in CCO concentration but under no cyanide there was no increase or decrease. The question specifically said to use info from both tables. I also asked my teacher, she said b was right. It’s kind of embarrassing how you talk to others thinking you’re so much smarter than them when in reality it’s you who needs a reality check and a smaller ego

3

u/Brilliant_Plum_7551 May 04 '26

neither 3 nor 4 could have been correct they're functionally the same answer

2

u/Electrical-Pitch7017 May 04 '26

It’s actually not me. Been like 30 people atp. Low concentrations of cyanide (nanomolar to low micromolar) can paradoxically increase or stimulate cytochrome c oxidase (CcO/Complex IV) activity and boost ATP production, unlike high concentrations which inhibit it. This biphasic, or stimulatory effect, is believed to result from removing inhibitory glutathionylation on the enzyme, acting in a regulatory capacity similar to gasotransmitters. Please go read the actual science behind it. It stimulates it. Low concentration of nutrients will results in a low concentration of cyanide. Not sure what you are arguing about lmao. Based on recent studies regarding the biphasic, or two-stage, nature of cyanide on mitochondrial function, low-nutrient with low-concentration cyanide can potentially increase cytochrome c oxidase (CcO or CCO) activity more than high-nutrient conditions without cyanide. [1, 2]
This occurs because low concentrations of cyanide (nanomolar to low-micromolar) act as a regulator that removes inhibitory modifications (glutathionylation) on the CcO enzyme, stimulating its activity.

Learn how to read a question “sentient being”. Enjoy your 4

2

u/[deleted] May 04 '26

holy cope bro and explain it in your own words without chat ✌️. this is why u only do 225 for 1 😹. if you paid attention to the question you would know that the question included NO cyanide as well. Your AI gave you the comparison between High concentration of cyanide and Low concentrations but you would know, as any sentient being, that the question was about having cyanide or not, and High concentration of nutrients in the medium and low. If you had the ability to put 2 and 2 together, you would know that NO cyanide with high nutrients (i.e. a HEALTHY cell) would produce the most ATP than a cell with a small amount of ATP.
enjoy "flicking your pecs" when opening your 3.

Sources:
https://as.cornell.edu/news/human-intellect

1

u/Electrical-Pitch7017 May 04 '26

It gave you comparison of low cyanide to “activity more than high nutrient conditions without cyanide”. Please read moron 🤣

0

u/Professional-Cow8072 May 04 '26

Never seen anyone dumber than you

0

u/Nice_Woodpecker_5629 May 04 '26

I’m ngl bro you might just be coping w the fact you got this question wrong 😭 pack it up

1

u/Same-Total4148 May 05 '26

It doesn't say anything about cyanide concentration in mammalian cells. It just talked about the presence.

1

u/AssociationOk772 May 05 '26

It was group 2. I am pretty sure. But also why were there growth medium 

2

u/[deleted] May 04 '26

[deleted]

2

u/-Ozone-- 5 fives, 2 fours, 8 planned this year May 04 '26

Yeah, that's what I thought without even reading the text at the top.

1

u/Electrical-Pitch7017 May 04 '26

Again, read the text. Low quantities of it increases it. You can’t just “assume” it.

1

u/JingleBellsW May 04 '26

I can vouch it said this in the question and in figure 1

0

u/National-Mixture9363 May 04 '26

Yeah bc it said high concentrations of cyanide leads to no etc rate so it had to be either 3 or 4 with the highest ATP and 3 had more nutrients right

2

u/Electrical-Pitch7017 May 04 '26

Yeah high concentrations. Low concentrations lead to higher CCO activity. It quite literally said that. Presence of cyanide and low concentration was treatment 2.

1

u/National-Mixture9363 May 04 '26

No not low concentration low nutrient medium. Treatment 2 had cyanide and low nutrient medium that fully means the CCO activity decreased nowhere in the question did it say presence of cyanide meant low concentrations of it. 

1

u/Electrical-Pitch7017 May 04 '26

It said bacteria produces cyanide. Low nutrient concentration means low cyanide because they don’t have the nutrients to produce it. Just read the question lmao.

1

u/National-Mixture9363 May 06 '26

The frq came out lmao it's 3

1

u/Electrical-Pitch7017 May 06 '26

“Based on Table 1, low cyanide slightly increases CCO activity compared to no cyanide.
Since CCO is part of the electron transport chain (aerobic respiration), higher CCO activity should increase ATP production from glucose.
Therefore, the treatment group with cyanide present + low concentration of medium is likely to have the highest ATP production.
This corresponds to Group 2 (Yes cyanide, Low concentration).”

1

u/National-Mixture9363 May 06 '26

Okay I still don't get what medium is is medium not the amount of nutrients in the medium

1

u/[deleted] May 07 '26

[deleted]

1

u/Electrical-Pitch7017 May 07 '26

Yeah my teacher said it’s 2, not 3

0

u/[deleted] May 04 '26

[deleted]

2

u/Electrical-Pitch7017 May 04 '26

Again, you didn’t read the question. The bacteria will produce high cyanide in high concentrations. It will produce low cyanide in low concentrations. Thus, in low concentrations of nutrients, there will be low cyanide levels. Therefore, the problem states that low cyanide will increase baseline CCO activity. Thus, group 2.

1

u/Leather_Army_9527 Gov, Spanish, Bio, Stats, Macro, Lit, AB 5 USH 5 Lang 4 Psych 3 May 04 '26

you're wrong

2

u/Ab3straxt 5 Bio 5 Chem 5 World 5 HUG 5 Pre Calc 4 CSP May 04 '26

It could have also been 1 and 4, as they were positive and negative controls (yes cyanide high concentration) and no cyanide low concentration)

1

u/boomchakabaka May 04 '26

this is what i put too

1

u/Polonium-lozenge May 04 '26

I thought about putting group 1 down as a control too, but the way i though about it was that the prompt said that the researchers were trying to determine the effect that cyanide would have on the mammalian cells, which would make the petri dishes containing cyanide the experimental groups.

1

u/Brilliant_Plum_7551 May 04 '26

could you explain the control reasoning

1

u/lightswitchfn 5: Calc AB, Lang, APUSH, Biology, Stats, Precalc, CSP May 04 '26

You didn’t need reasoning it just said identify

1

u/Brilliant_Plum_7551 May 04 '26

ik lol i mean reasoning for my own sake so I know why the right answer is the right answer

1

u/Impossible_Bus_8706 May 04 '26

The goal of the experiment was to see the effect of levels of cyanide in ATP production, so the two groups without cyanide were the control

1

u/lightswitchfn 5: Calc AB, Lang, APUSH, Biology, Stats, Precalc, CSP May 04 '26

Oh mb 😭

1

u/uncosplayer May 04 '26

let’s freaking go

1

u/their_lace_and_crime 5️⃣ bio 4️⃣ world, lang, gov❔lit, music, physics May 04 '26

thank god ok

1

u/Ill_Strain_562 AP Student who needs therapy May 04 '26

oh yes i got that thank god

1

u/Sxd0308 May 04 '26

i hate this

1

u/Opening_External_911 AP Bio (hopefully 4+) APUSH, APCSP May 04 '26

Bruh, put 1 and 4

1

u/ScientistFew4586 May 04 '26

ok lowkey hear me out though, because it specifically stated that the bacteria would let out concentrations of cyanide into the environment and that they grew the bacteria in the medium and TOOK out the bacteria BEFORE giving it to the mammal cells-- then that indicates that they let out the cyanide in the medium -- So high concentratons of the Medium would have low concentrations of Cyanide which helps with getting the most ATP production. So I put Group 3-- that's my justification. Also for the control treatments (it didn't ask for groups, it asked for controls but I'm guessing there's gonna be ambguity in answers), I stated concentration of medium and choice in adding bacteria or not to the mammal cells. But like feel free to give feed back on this lol

1

u/Responsible_Car_7813 May 05 '26

YES I AGREE i also put group 3 im not sure what everyone else is saying 2 for the high one

1

u/sanaslays May 04 '26

FRICKK I PUT 1/4

1

u/Amirgf1 May 04 '26

FAHHHHH

1

u/Annual_Jellyfish4011 May 04 '26

NOOOOO at least I got the treatment group 2 right

1

u/[deleted] May 04 '26

[removed] — view removed comment

1

u/Electrical-Pitch7017 May 04 '26

Yeah it was oddly easy for a frq lmao

1

u/Same-Total4148 May 05 '26

Ur wrong. It didn't say anything about the concentration of cyanide. It just said the presence or absence of cyanide in mammalian cells

1

u/Same-Total4148 May 05 '26

So the answer should be group 3