Accounts aren't open yet. We're finishing the question bank first. Join the waitlist
CAIE A-level Biology, Chemistry & Maths
See exactly where your marks come from.
Write your answer. It comes back with the mark scheme laid over the top, so you can see which marks you got and what the ones you missed needed.
It'll be free to start, and there's no card at signup.
Explain how the tertiary structure of an enzyme is important for its function.
Your answer
The tertiary structure gives the enzyme its 3D shape, which makes the active site a specific shape. This means only the right substrate can fit into the active site and bind to it. If the shape changes then the substrate won't fit anymore and the enzyme won't work.
- AwardedYou correctly stated that tertiary structure forms the specific 3D shape of the active site.1/1
- AwardedYou explained that the shape allows complementary binding of the substrate.1/1
- MissedYou did not mention that binding lowers activation energy or increases reaction rate.0/1
You explained the importance of shape and substrate binding well. Work on linking binding to lowering activation energy or increasing reaction rate.
This is real marking. Every word in the boxes above is what our marker actually wrote about that answer.
Answering the question is the easy half.
You do the past paper. You check it against the answers at the back, decide you'd have got most of that, and move on. Then the real one comes back 4 out of 9 and you still don't know which four.
Testing yourself beats re-reading your notes. That part is settled, and it's why everyone tells you to do past papers. The bit that gets left out is that it only pays off if you find out what you actually got wrong. For a written answer, you can't do that on your own. You can't spot the mark scheme point you've never read.
So that's the job here. You write it, we mark it against the scheme, and you find out.
The research, if you want it: testing beats re-reading and it works better when you're told what you missed.
How it works
Three steps, and the third is the one that matters.
Pick a topic
Start with something from the syllabus you know you're shaky on. The questions follow your board's spec and sit under the same topics.
Answer it properly
Write it out the way you would in the exam. There's no timer and nothing counting your streak. You're here to find out what you know.
See where the marks went
The scheme comes back laid over your answer, with the reason for every mark you did and didn't get.
How the marking works
It only ever uses the mark scheme.
Every question has a mark scheme stored with it. The marker works through that scheme and nothing else. It can't make up a criterion, and it can't hand you a mark the scheme doesn't have. Where a mark depends on you using a particular term, we check for the term itself, so a near-miss paraphrase won't slip through.
A score on its own would be close to useless. The research on feedback is blunt about it: being told whichpoint you dropped, and why, is worth several times more than a number out of three. So that's what comes back.
CAIE Mathematics 9709
Maths is checked, not guessed.
Your working never goes near a language model. An engine reads what you wrote and checks it against the answer key, so the same answer earns the same mark every time you press submit.
- Units. A wrong unit costs you the unit mark. The rest of the question stands.
- Error carried forward. Slip early, stay consistent, and the later marks still come, wherever the scheme allows it.
- Method marks. A correct final answer earns everything except the method mark. That one needs your working.
Deterministic engine · no AI
Illustrative example.
Paste your own answer
“Evaluate the view that inflation is best controlled by monetary policy.”
Illustrative example.
Essay marking
Bring an essay that isn't ours.
Paste in an essay you've written for an A-level and it comes back marked against that paper's criteria, with the reasoning written out. Nine subjects across AQA, CAIE, Edexcel and OCR: Business, Economics, English Literature, Geography, History, Politics, Psychology, Religious Studies and Sociology.
Part of Pro
Find out what you actually know.
Everything you've been marked on adds up. You get a topic-by-topic read on where you're solid and where you're quietly dropping marks, plus a predicted grade worked out from your answers and nothing else.
It won't show you a grade early. You need a few topics covered properly first, with enough questions in each and about 40% of the syllabus done. A grade off the back of four questions is just a guess with a decimal point.
Predicted grade
Biology · 47% of the syllabus
A
Where your marks go
Accuracy over time
+12 pts in 3 weeks
Illustrative example.
Your parents see how it's going. That's all.
If you want a parent to follow along, you make a code and hand it over. They get a straight read on how much you're practising and how you're doing. They never see what you actually wrote.
Off until you say so
Nothing is shared until you generate a code.
You can see their view
A page shows you exactly what they see.
Undo it any time
Disconnect a parent whenever you like.
Questions
Right now it's CAIE A-level Biology (9700), Chemistry (9701) and Mathematics (9709), sorted by syllabus topic. Those are the only three, and we'd rather say so than list boards we haven't built yet. You can tell us which ones you want when you set up your account, and that's genuinely how we decide what comes next.
It reads your written prose answers, and even then it marks against that question's stored mark scheme and can't invent criteria of its own. Multiple choice is scored by fixed rules. Maths goes through an engine that does the same arithmetic every time. There is no AI anywhere in the maths marking path.
We compare what you wrote against the mark scheme for that question, and work through it the way an examiner does, deciding each mark on its own. Then you're told in plain English which points you got, which you didn't, and what the ones you missed were looking for. A few questions are marked in bands instead of points, and those come back with the band and the reasoning behind it.
It will be, and you won't need a card. Free will get you unlimited multiple choice, 3 written answers marked a day, the question bank, and your full history. Pro takes the daily cap off and adds your predicted grade and the topic breakdowns. The prices on the pricing page are the ones we'll open with.
From your marked practice and nothing else. We look at how you score in each topic and work out a grade per subject. It holds off until you've covered a few topics properly, with enough questions in each and about 40% of the syllabus done, so the number means something when it finally appears. It's deliberately cautious. Predicted grades are part of Pro.
Yes. Paste in your own A-level essay and it comes back marked against that paper's criteria. Nine subjects across AQA, CAIE, Edexcel and OCR. It runs on credits rather than your daily allowance: Pro includes some each day, and anyone can buy a pack. We've checked the marking against real graded scripts for five of those combinations so far, and where we haven't, the app says so before you spend a credit.
Nothing at all until you connect them. You generate a code in your account and give it to them, and from then on they can see how much you're practising and how you're getting on. They never see the answers you wrote. There's a page that shows you their exact view, and you can disconnect them whenever you want.
Yes. This is the testing-yourself step, so it goes alongside your notes rather than replacing them. Reading is how you learn it. Being marked is how you find out whether you actually did.
Find the marks you've been missing
Accounts open once the question bank is done. Leave your email and we'll tell you the day that changes.
Join the waitlistOne email when it opens, and nothing else. See what it'll cost