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3 Cards in this Set
- Front
- Back
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Catalytic cycle of an enzyme |
Substrates enter active site; enzyme changes shape so that its active site enfolds the substrate. Substrates are held in place by weak interactions like hydrogen and ionic bonds. Substrates are converted to products. Products are released. Active site is available for 2 new substrate molecules. |
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Mechanisms used to reduce activation energy of an enzyme |
Active site provides a template on which the substrates can come together in proper orientation for a reaction to occur. Enzyme can stretch the substrate molecules it holds toward their transition-state form, bending and breaking critical chemical bonds.The active site can provide a microenvironment that is more conducive to a particular type of reaction. Fourth mechanism is the direct participation of the active site in the chemical reaction. |
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Explain the steps involved in the production of ATP by ATP synthase |
1. H+ions flowing down their gradient enter a half channel in a stator, which is anchored in the membrane. 2. H+ ions enter binding sites within a rotor, changing the shape of each subunit so that the rotor spins within the membrane. 3. Each H+ ion makes one complete turn before leaving the rotor and passing through a second half channel in the stator into the mitochondial matrix. 4. Spinning of the rotor causes an internal rod that extends into a knob below it to spin. 5. Turning of the rod activates catalytic sites in the knob that produce ATP from ADP and OPi |
