Gibbs Free Energy

Summary

In this podcast, Mr. Andersen simplifies the complex concept of Gibbs Free Energy, also known as available energy, to make it more accessible. He explains the significance of spontaneous reactions, highlighting examples like a ball rolling down a slide, diffusion, and the explosion of a cherry bomb. The discussion covers key terms like enthalpy and entropy, demonstrating how these elements influence spontaneity in reactions. Mr. Andersen concludes with real-life applications, emphasizing the role of cellular respiration and photosynthesis in energy transfer, ultimately illustrating how energy transitions from sunlight to usable forms in living organisms.

Takeaways

• 😀 Gibbs Free Energy is also known as available energy, essential for doing work in biological systems.
• 🔄 Spontaneous reactions occur when a system can proceed without additional energy input after an initial push.
• ⚖️ Enthalpy (H) represents the total energy of a system, which decreases during spontaneous reactions.
• 🌪️ Entropy (S) measures the disorder or randomness of a system, which increases in spontaneous processes like diffusion.
• 💥 The activation energy is the initial energy required to start a reaction, even if it is spontaneous afterward.
• 🍃 Cellular respiration is an example of a spontaneous (exergonic) reaction, releasing energy as glucose is broken down.
• 🌞 Photosynthesis is an endergonic reaction, requiring energy (from sunlight) to convert carbon dioxide and water into glucose.
• 💰 ATP (adenosine triphosphate) is the energy currency of cells, storing and releasing energy as needed.
• 📉 A negative delta G indicates a spontaneous reaction, while a positive delta G indicates a non-spontaneous reaction.
• 🔄 The flow of energy in biological systems involves converting sunlight into chemical energy and then into usable energy for cellular processes.

Q & A

What is Gibbs Free Energy often referred to as?

Gibbs Free Energy was previously known as 'available energy,' which emphasizes its role as energy that can be used to do work.

What are spontaneous reactions?

Spontaneous reactions are those that, once initiated with a small amount of energy, will proceed on their own and typically release energy to their surroundings.

Can you give an example of a spontaneous reaction mentioned in the podcast?

An example of a spontaneous reaction is cellular respiration, where glucose is broken down to release energy.

How does the concept of enthalpy relate to Gibbs Free Energy?

Enthalpy, represented as H, refers to the total energy of a system. In spontaneous reactions, the enthalpy tends to decrease, which can lead to a decrease in Gibbs Free Energy (ΔG).

What is entropy and how does it affect reactions?

Entropy, symbolized as S, measures the disorder or randomness of a system. In spontaneous reactions, the entropy tends to increase, which can also decrease Gibbs Free Energy (ΔG).

How does temperature influence spontaneous reactions?

Increasing temperature can make a reaction more spontaneous. In the context of the cherry bomb example, raising the temperature increases the likelihood of an explosion.

What determines if a reaction is spontaneous according to Gibbs Free Energy?

A reaction is considered spontaneous if the change in Gibbs Free Energy (ΔG) is less than zero, indicating an exergonic reaction that releases energy.

What is the difference between exergonic and endergonic reactions?

Exergonic reactions have a negative ΔG and release energy, while endergonic reactions have a positive ΔG and require energy input.

What role does ATP play in cellular processes?

ATP (adenosine triphosphate) acts as the energy currency of cells, storing energy that can be used for cellular functions when it breaks down into ADP (adenosine diphosphate).

How do photosynthesis and cellular respiration relate to Gibbs Free Energy?

Photosynthesis is an endergonic reaction with a positive ΔG, requiring energy, while cellular respiration is an exergonic reaction with a negative ΔG, releasing energy, which is essential for life.