Biology Free Energy and Reactions

Questions and Answers

What is free energy?

The portion of a biological system's energy that can perform work when temperature and pressure are uniform throughout the system.

What is the equation for calculating the change in free energy (△G)?

△G = △H - T△S

What is an exergonic reaction?

A spontaneous chemical reaction in which there is a net release of free energy.

What is an endergonic reaction?

A non-spontaneous chemical reaction in which free energy is absorbed from the surroundings. Signup and view all the answers

What is ATP (adenosine triphosphate)?

An adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed. Signup and view all the answers

What is a phosphorylated intermediate?

A molecule with a phosphate group covalently bound to it, making it more reactive than the unphosphorylated molecule. Signup and view all the answers

What is energy coupling?

The use of energy released from an exergonic reaction to drive an endergonic reaction. Signup and view all the answers

Study Notes

Free Energy

Represents the portion of energy in a biological system available to perform work under uniform temperature and pressure.
Change in free energy (△G) is calculated using the equation: △G = △H - T△S.
△H signifies change in enthalpy (total energy), T is absolute temperature, and △S is change in entropy.

Exergonic Reaction

Defined as a spontaneous chemical reaction.
Characterized by a net release of free energy during the reaction.

Endergonic Reaction

A non-spontaneous chemical reaction that requires an input of free energy.
Free energy is absorbed from the surroundings to drive the process.

ATP (Adenosine Triphosphate)

Composed of adenine, ribose, and three phosphate groups.
Releases free energy upon hydrolysis of its phosphate bonds.
This energy is utilized to energize endergonic reactions within cells.

Phosphorylated Intermediate

A compound with a covalently attached phosphate group.
Increases reactivity and decreases stability compared to its unphosphorylated form, facilitating chemical reactions.

Energy Coupling

Involves using energy released from exergonic reactions to power endergonic reactions.
Essential in cellular metabolism for efficient energy use and reaction management.

Description

Explore the concepts of free energy in biological systems, including exergonic and endergonic reactions. Learn how ATP functions as a key energy currency and the importance of phosphorylated intermediates. This quiz will test your understanding of thermodynamics in biological processes.