learning outcomes b11- analyse the roles of enzymes in biochemical reactions explain the following...

Download Learning Outcomes B11- analyse the roles of enzymes in biochemical reactions explain the following terms: metabolism, enzyme, substrate, coenzyme, activation

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  • Learning OutcomesB11- analyse the roles of enzymesin biochemical reactionsexplain the following terms: metabolism, enzyme, substrate, coenzyme, activation energyuse graphs to identify the role of enzymes in lowering the activation energy of a biochemical reactionexplain models of enzymatic action (e.g., induced fit)

  • What do you know about enzymes?Definition?Function?Some examples in the body?Type of molecule?Where are they made?

  • Thinking Question..What are some chemical reactions that occur in the human bodyTo break down substances?

    To synthesize substances?

  • Metabolic PathwaysCellular metabolism consists of many different chemical reactionsReactions result in synthesis or breakdown of substancesMost reactions occur in several steps (metabolic pathways)

  • Each reaction is catalyzed by a different enzyme

    A B C DE1E2E3

  • ENZYMESAre usually proteinsEach have a specific shapeAre specific for one reactionAct as organic catalystsAre not used up in the reaction

  • SUBSTRATESAre the reactants in enzyme-catalyzed reactionsMay be broken down (ex. hydrolysis), or combine with other substrates (synthesis)Are used up in the reaction to produce products

  • What are some examples of substratesOf digestive enzymes?Of the enzyme DNA polymerase?Of enzymes in the mitochondria?Of hydrolytic enzymes in the lysosomes?

  • Examples of enzymesPolymerases - catalyze polymerization reactionsCatalase - breaks down hydrogen peroxide (H2O2)Digestive enzymes - amylase, lipase, lactase, etc. (names usually end in ase)

  • Enzyme activityAll chemical reactions have a specific energy of activation, needed to get the reaction startedEnzymes lower the energy of activation of a chemical reaction, allowing the reaction to take place with a lower input of energy (at body temperature)

  • Fig. 6.5

  • Enzymes are specific for a particular substrate due to their shape

  • Lock and key modelThe active site of an enzyme binds to the substrate like a lock-and-key An enzyme - substrate complex is formed

  • Induced fit modelSometimes the active site of an enzyme may change shape to fit the substrate

  • Fig. 6.7

  • The reaction occurs while the substrate is attached to the enzymeAfter the reaction is complete, the products are releasedThe enzyme is now free to combine with another molecule of substrate

  • TA p113

  • Fig. 6.6

  • *Need clay, lego blocks to model synthesis, hydrolysis, induced fit***********