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Cards In This Set
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Define catabolic pathways.
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"breakdown pathways" - Releases energy by breaking down complex molecules to simpler ones.
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Define anabolic pathways.
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Construct molecules from smaller units. Consume energy to build complicated molecules.
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Explain the role of catabolic and anabolic pathways in the energy exchanges of cellular metabolism.
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They are the "downhill" and "uphill" avenues of the metabolic map - energy released from the downhill reactions of catabolic pathways can be stored and then used to drive the uphill reactions of anabolic pathways.
*Catabolic releases energy - Anabolic consumes energy |
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Explain the first and second Law of Thermodynamics.
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FIRST = energy can be transferred and transformed, but it cannot be created or destroyed
SECOND = every energy transfer or transformation increases the randomness (entropy) of the universe |
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Explain why highly ordered living organisms do not violate the Second Law of Thermodynamics.
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"During the early history of life, complex organisms evolved from simpler ancestors"
The entropy of a particular system, such as an organism, may actually decrease as long as the total entropy of the universe increases. (Evolution of biological order is perfectly consistent with the law's) |
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Define and Explain the usefulness of free energy.
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Free Energy = Portion of a systems energy that can perform work when temperature and pressure are the same throughout the system [as in the living cell] "Energy is available"
Usefulness; Helps in a systems stability and equilibrium |
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Describe the function of ATP in the cell.
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(Energy used) by organisms to perform cellular work, represents potential energy, couples anabolic and catabolic reactions
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Describe the role of ATP in coupled reactions.
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Responsible for mediating most energy coupling in cells - the idea is to couple a synthetic reaction with another reaction that converts ATP to ADP and gives up some extra energy that is needed for the synthesis
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List the 3 components of ATP and identify the major class of macromolecules to which it belongs.
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Sugar RiboseAdenine (nitrogenous base)3 Phosphate Groups
- Nucleotide |
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Explain how ATP performs cellular work.
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The cell's proteins harness the energy released during ATP exergonic hydrolysis - leads to either chemical, transport or mechanical work
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Describe the energy profile of a chemical reaction; (including activation energy, free energy change, and transition state).
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Sugar molecule is broken down into simpler molecules. Activation energy; amount of energy that reactant molecules must absorb to start a reaction - Free energy change; difference in free energy between products and reactants - Transition state - unstable condition of reactant molecules that have absorbed sufficient free energy to react
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Explain the induced fit model of enzyme function and describe the catalytic cycle of an enzyme.
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(Glucose) glucose then binds, then into an induced fit where ATP binding is enhanced, then goes to products released then into an enzyme that becomes available again
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Explain how substrate concentration affects the rate of an enzyme-catalyzed reaction.
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As the concentration of substrate increases, the rate of reaction also increases until the point saturation occurs.
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Define metabolism - (function, as well)
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Totality of an organism's chemical reactions
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Explain how temperature and pH affect enzyme activity.
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Temperature; The rate of enzymatic reaction increases with increasing temperature - because substrates collide with active sites more frequently when the molecules move rapidly.
pH; Enzymes cannot function at too high or too low a PH. Too acidic solutions means the H+ ions interfere with the enzymes amino acid sequence, causing the enzyme to change shape and become denatured. |
