Here's why:
* Gibbs Free Energy (ΔG): This thermodynamic quantity tells us whether a reaction will occur spontaneously or not.
* Endergonic Reactions: These reactions require energy input to proceed. They are non-spontaneous.
* Positive ΔG: A positive change in Gibbs free energy means the products have higher free energy than the reactants. This indicates that the reaction needs energy to occur.
Think of it like pushing a ball uphill:
* Exergonic (spontaneous): Rolling a ball downhill, releasing energy. ΔG is negative.
* Endergonic (non-spontaneous): Pushing a ball uphill, requiring energy. ΔG is positive.
Examples of endergonic reactions:
* Photosynthesis: Plants use sunlight energy to convert carbon dioxide and water into glucose.
* Protein synthesis: Cells use energy to build complex proteins from amino acids.
