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  2. Catalysis - Wikipedia

    en.wikipedia.org/wiki/Catalysis

    The reaction occurs in two steps: 2 NO + O 2 → 2 NO 2 (rate-determining) NO 2 + SO 2 → NO + SO 3 (fast) The NO catalyst is regenerated. The overall rate is the rate of the slow step [14] v=2k 1 [NO] 2 [O 2]. An example of heterogeneous catalysis is the reaction of oxygen and hydrogen on the surface of titanium dioxide (TiO 2, or titania) to ...

  3. Catalytic cycle - Wikipedia

    en.wikipedia.org/wiki/Catalytic_cycle

    In such loops, the initial step entails binding of one or more reactants by the catalyst, and the final step is the release of the product and regeneration of the catalyst. Articles on the Monsanto process, the Wacker process, and the Heck reaction show catalytic cycles. Catalytic cycle for conversion of A and B into C

  4. Enzyme catalysis - Wikipedia

    en.wikipedia.org/wiki/Enzyme_catalysis

    These conformational changes also bring catalytic residues in the active site close to the chemical bonds in the substrate that will be altered in the reaction. After binding takes place, one or more mechanisms of catalysis lowers the energy of the reaction's transition state, by providing an alternative chemical pathway for the reaction.

  5. Heterogeneous catalysis - Wikipedia

    en.wikipedia.org/wiki/Heterogeneous_catalysis

    Most metal surface reactions occur by chain propagation in which catalytic intermediates are cyclically produced and consumed. [8] Two main mechanisms for surface reactions can be described for A + B → C. [2] Langmuir–Hinshelwood mechanism: The reactant molecules, A and B, both adsorb to the catalytic surface. While adsorbed to the surface ...

  6. Reaction mechanism - Wikipedia

    en.wikipedia.org/wiki/Reaction_mechanism

    In chemistry, a reaction mechanism is the step by step sequence of elementary reactions by which overall chemical reaction occurs. [1] A chemical mechanism is a theoretical conjecture that tries to describe in detail what takes place at each stage of an overall chemical reaction. The detailed steps of a reaction are not observable in most cases.

  7. Enzyme kinetics - Wikipedia

    en.wikipedia.org/wiki/Enzyme_kinetics

    Although these mechanisms are often a complex series of steps, there is typically one rate-determining step that determines the overall kinetics. This rate-determining step may be a chemical reaction or a conformational change of the enzyme or substrates, such as those involved in the release of product(s) from the enzyme.

  8. CNO cycle - Wikipedia

    en.wikipedia.org/wiki/CNO_cycle

    Unlike the proton-proton reaction, which consumes all its constituents, the CNO cycle is a catalytic cycle. In the CNO cycle, four protons fuse, using carbon , nitrogen , and oxygen isotopes as catalysts, each of which is consumed at one step of the CNO cycle, but re-generated in a later step.

  9. Biosynthesis - Wikipedia

    en.wikipedia.org/wiki/Biosynthesis

    Biosynthesis occurs due to a series of chemical reactions. For these reactions to take place, the following elements are necessary: [1] Precursor compounds: these compounds are the starting molecules or substrates in a reaction. These may also be viewed as the reactants in a given chemical process.