Biology  by Bradford
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3.1 Enzymes: revision map

The subtopic in the middle and five tasks round it: label two diagrams, complete a table, put a process in order and fill 15 gaps. Every box rests on a learning objective of the topic in the AP Biology course and exam description. Type into the blanks and check them, or print it on A4, Letter or A3 with an answer key.

Unit 3 practice questionsThe whole Unit 3 map

Topic 3.1

Enzymes

AP Biology · Unit 3 Cellular EnergeticsName

3.1.AEnergy profile of a reaction

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3.1.AHow a catalyst helps

Most reactions need a push to get started: the reactants must reach a transition state, and the energy needed is the . An enzyme speeds up a reaction by lowering that barrier, so more molecules have enough energy to react at body temperature. It does not change the free energy of the reactants or products, and it is by the reaction. Every enzyme is a protein (or occasionally RNA) with an active site into which one substrate, or a few, fit.

3.1.AOne turn of the cycle

Number the steps in order.

  1. The free enzyme is ready to bind another substrate.
  2. Bonds in the substrate are strained and the reaction occurs.
  3. The products are released.
  4. The substrate enters the active site of the enzyme.
  5. The active site changes shape slightly to grip the substrate: induced fit.
Topic 3.1Enzymes

3.1.AThe enzyme cycle

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3.1.AEnzyme words

TermMeaning
the reactant an enzyme acts on
the region where the reactant binds and the reaction takes place
the binding region adjusts its shape as the reactant binds
Specificityeach enzyme binds only molecules of a particular shape and charge
Word bank activation energyactive siteActive siteenzymeenzyme-catalyzed reactionenzyme-substrate complexfree energy releasedInduced fitnot used upproductsreactantssubstrateSubstrate

Answer key

Every box on the sheet with its gaps filled in, as the subtopic reads in full.

  1. LabelThe enzyme cycle

    1. enzyme
    2. substrate
    3. active site
    4. enzyme-substrate complex
    5. products

  2. LabelEnergy profile of a reaction

    1. reactants
    2. products
    3. activation energy
    4. enzyme-catalyzed reaction
    5. free energy released

  3. GapsHow a catalyst helps

    Most reactions need a push to get started: the reactants must reach a transition state, and the energy needed is the activation energy. An enzyme speeds up a reaction by lowering that barrier, so more molecules have enough energy to react at body temperature. It does not change the free energy of the reactants or products, and it is not used up by the reaction. Every enzyme is a protein (or occasionally RNA) with an active site into which one substrate, or a few, fit.

  4. OrderOne turn of the cycle

    1. The substrate enters the active site of the enzyme.
    2. The active site changes shape slightly to grip the substrate: induced fit.
    3. Bonds in the substrate are strained and the reaction occurs.
    4. The products are released.
    5. The free enzyme is ready to bind another substrate.

  5. TableEnzyme words

    TermMeaning
    Substratethe reactant an enzyme acts on
    Active sitethe region where the reactant binds and the reaction takes place
    Induced fitthe binding region adjusts its shape as the reactant binds
    Specificityeach enzyme binds only molecules of a particular shape and charge