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Why enzymes denature

High temperatures break the bonds holding an enzyme in shape. Its active site changes shape, so the substrate no longer fits.

Common mistake: enzymes are not killed, because they were never alive.

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Practise until exam day feels easy

  • Question 4
  • Physics
  • SL
  • Paper 1

A ball is thrown straight up and air resistance is negligible. Which statement is correct?

  • AKinetic energy stays constant all the way up
  • BAcceleration is zero at the highest point
  • CVelocity is zero at the highest point Correct
  • DThe resultant force acts upwards

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Extended Essay draft: feedback by criterion

  1. A. Focus and methodResearch question is clear and narrow.
  2. B. Knowledge and understandingDefine key terms in section 2.
  3. C. Critical thinkingAdd counter-arguments to your analysis.
  4. D. PresentationCheck the citation format.
  5. E. EngagementAdd more reflection on how your thinking changed.
    1. 1Research question
    2. 2Methodology
    3. 3Analysis
    4. 4Evaluation
    5. 5Word count

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  • Sources cited

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  • 7

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    See what high-scoring coursework looks like, with notes on why it scored well.

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Why does a catalyst not change the equilibrium position?

It speeds up the forward and reverse reactions equally. You reach equilibrium sooner, but the balance between them stays the same. Want a practice question on this?

  • Quiz me on bonding
  • Explain integration by parts
  • Make flashcards for Unit 2
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  • Physics
  • SL
  • Paper 2

A ball is thrown vertically upward at 12 m/s. Calculate its maximum height. [2 marks]

Student answer: h = 144 ÷ 9.8 = 14.7 m

Mark scheme: 1 of 2

  • M1 Uses v² = u² − 2gh with v = 0 (mark earned)
  • A1 Height = 7.3 m, with a correct unit (mark not earned)

To fix: you missed the 2 in 2g, so divide 144 by 19.6.

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Every answer is checked against the mark scheme, so you see which marks you earned and what to change for the rest.

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Extended Essay draft: feedback by criterion

  1. A. Focus and methodResearch question is clear and narrow.
  2. B. Knowledge and understandingDefine key terms in section 2.
  3. C. Critical thinkingAdd counter-arguments to your analysis.
  4. D. PresentationCheck the citation format.
  5. E. EngagementAdd more reflection on how your thinking changed.

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Study planner

Subjects, deadlines and goals turned into a week you can keep.

This week's plan

Monday

  • Enzymes questions20 min
  • Atomic structure notes15 min

Tuesday

  • Spanish vocabulary10 min
  • Essay outline for English30 min

Progress

Time, accuracy and weak topics across every subject.

Your progress

Time studied this week: 6 h 40 min

Accuracy by topic

  • Cell biology82%
  • Genetics64%
  • Ecology48%

Topics covered

11 of 18 topics revised

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Saved for later

Keep tricky questions and notes in one list to revisit.

  • Enzyme kinetics, Q12
  • Command terms: evaluate
  • Integration by parts

Exam countdown

See how long is left for each paper.

  • Biology Paper 118 days
  • Maths AA Paper 223 days
  • English A Paper 131 days

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