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3: Bioenergetics - Thermodynamics and Enzymes

  • Page ID
    16106
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    • 3.1: The Laws of Thermodynamics
      This page explains the First and Second Laws of Thermodynamics as they relate to living organisms, emphasizing energy conservation, entropy, and the necessity of energy input for cellular order. It details how cells couple exergonic and endergonic reactions using ATP hydrolysis to drive non-spontaneous processes. The unique properties of ATP, such as electrostatic repulsion and resonance stabilization, enhance its role in energy transfer.
    • 3.2: Enzymes
      This page discusses enzymes, which are proteins that act as biological catalysts, increasing the speed of chemical reactions dramatically. They function through specific interactions with substrates, classified into six categories based on their roles. The regulation of enzyme activity is vital for cells to adapt to changes, as enzymes lower activation energy, thus improving the efficiency of essential biochemical reactions.
    • 3.3: Enzyme Kinetics
      This page explains the differences between enzyme-catalyzed and uncatalyzed reactions, highlighting that rates depend on enzyme availability and reach a maximum rate \(V_{max}\) at high substrate levels. It introduces the Michaelis-Menten equation and the Michaelis constant \(K_m\), which represents the substrate concentration at half-maximal reaction rates.
    • 3.4: Regulation of Enzyme Activity
      This page covers enzyme inhibition, detailing reversible and irreversible inhibitors, competitive and non-competitive inhibition, and allosteric regulation. It also introduces advanced concepts like uncompetitive and mixed inhibition, and the role of phosphorylation in enzymatic regulation.

    Thumbnail: diagram showing the induced fit model in enzymes ( (Public Domain; LadyofHats).


    This page titled 3: Bioenergetics - Thermodynamics and Enzymes is shared under a CC BY-NC-SA 3.0 license and was authored, remixed, and/or curated by E. V. Wong via source content that was edited to the style and standards of the LibreTexts platform.