Free Energy and Biochemical Reactions Quiz

Questions and Answers

What does the free-energy change of a reaction tell us?

The temperature at which the reaction occurs

The speed of the reaction

The color change during the reaction

Whether or not the reaction occurs spontaneously (correct)

How does ATP power cellular work?

By increasing the energy of all reactions

By breaking down glucose molecules

By inhibiting metabolic reactions

By coupling exergonic reactions to endergonic reactions (correct)

How do enzymes speed up metabolic reactions?

By changing the nature of the reactants

By increasing energy barriers

By increasing the activation energy

By lowering energy barriers (correct)

How does the regulation of enzyme activity help control metabolism?

By controlling the rate of metabolic reactions Signup and view all the answers

What does entropy refer to?

The increase in disorder in a system Signup and view all the answers

How do living systems contribute to the entropy of their surroundings?

They increase the entropy of their surroundings Signup and view all the answers

What is the role of energy in ecosystems in relation to entropy?

Energy flows into ecosystems in the form of light and exits as heat, contributing to the overall increase in entropy Signup and view all the answers

What is the relationship between the increase in biological order over time and the second law of thermodynamics?

The increase in biological order over time does not violate the second law of thermodynamics Signup and view all the answers

What is a good analogy for an increase in entropy?

The physical disintegration of a system’s organized structure Signup and view all the answers

How do biological processes contribute to the increase in disorder?

Biological processes convert chemical energy to kinetic energy, increasing disorder by producing heat and less ordered forms of matter Signup and view all the answers

What accounts for the depletion of chemical energy in organisms?

Heat generated during metabolism Signup and view all the answers

What is consistent with the laws of thermodynamics?

The evolution of biological order Signup and view all the answers

What is Gibbs free energy, symbolized by G, a useful function for?

Measuring the portion of a system’s energy that can perform work when temperature and pressure are uniform throughout the system Signup and view all the answers

What is the first law of thermodynamics?

Energy can be transferred and transformed, but not created or destroyed Signup and view all the answers

What is metabolism?

The totality of an organism’s chemical reactions and an emergent property of life Signup and view all the answers

What do catabolic pathways do?

Release energy by breaking down complex molecules Signup and view all the answers

What is the second law of thermodynamics?

Every energy transfer or transformation increases the entropy of the universe Signup and view all the answers

What are metabolic pathways?

A series of defined steps that alter specific molecules, catalyzed by enzymes Signup and view all the answers

What is chemical energy?

The potential energy available for release in a chemical reaction; high in complex molecules like glucose Signup and view all the answers

What do anabolic pathways do?

Consume energy to build complicated molecules from simpler ones Signup and view all the answers

What is entropy?

A measure of the amount of disorder in a system Signup and view all the answers

What is bioenergetics?

The study of how energy flows through living organisms Signup and view all the answers

What is the capacity to cause change and exists in various forms?

Energy Signup and view all the answers

What do catabolic reactions release energy by?

Breaking bonds and forming new ones, resulting in lower-energy breakdown products Signup and view all the answers

Why is a basic knowledge of energy necessary?

To understand how the living cell works Signup and view all the answers

Which law of thermodynamics states that energy can be transferred and transformed, but not created or destroyed?

The first law Signup and view all the answers

What is the name of the study of energy transformations in matter?

Thermodynamics Signup and view all the answers

What does the second law of thermodynamics state about energy transfer or transformation?

Increases the disorder (entropy) of the universe Signup and view all the answers

What is the system in the context of thermodynamics?

The universe Signup and view all the answers

What is the name for the measure of molecular disorder used by scientists?

Entropy Signup and view all the answers

What is the unstoppable trend mentioned in the text?

Toward randomization of the universe as a whole Signup and view all the answers

What is the name of the energy transformation illustrated in Figure 8.2?

Between potential energy and kinetic energy Signup and view all the answers

What is the name of the energy converted to thermal energy and released as heat during energy transformation?

Usable energy Signup and view all the answers

When can a system put thermal energy to work?

When there is a temperature difference Signup and view all the answers

What does the loss of usable energy as heat to the surroundings do to the universe?

Makes the universe more disordered, increasing entropy Signup and view all the answers

What do organisms act as in the context of energy transformation?

Energy transformers Signup and view all the answers

What enables cells to release chemical energy from food molecules and use it to power life processes?

Biochemical pathways Signup and view all the answers

What is the equation to calculate the free-energy change (ΔG) for a chemical reaction?

ΔG = ΔH - TΔS Signup and view all the answers

What conditions can affect the ΔG value of a chemical reaction?

pH, temperature, concentrations of reactants and products Signup and view all the answers

What does a negative ΔG value indicate about a process?

The process is spontaneous Signup and view all the answers

What does a negative ΔG indicate about the free energy and stability of the final state?

Loss of free energy and increased stability Signup and view all the answers

What does free energy serve as a measure of in a system?

Instability and tendency to change to a more stable state Signup and view all the answers

What is the state of maximum stability in a system?

Equilibrium Signup and view all the answers

Can a system at equilibrium perform work?

No, a system at equilibrium cannot perform work Signup and view all the answers

How are chemical reactions classified based on their free-energy changes?

Exergonic (release of free energy) or endergonic (absorption of free energy) Signup and view all the answers

What happens in exergonic reactions?

They occur spontaneously due to the release of free energy Signup and view all the answers

How is free energy harnessed in spontaneous changes?

To perform work, such as gravitational motion and diffusion Signup and view all the answers

Why is understanding free energy crucial in the study of metabolism?

To determine which reactions can supply energy for cellular work Signup and view all the answers

What best describes the role of enzymes in speeding up metabolic reactions?

Enzymes decrease the activation energy required for a reaction to occur Signup and view all the answers

How does the free-energy change (ΔG) of a reaction relate to the spontaneity of the reaction?

A negative ΔG indicates a spontaneous reaction Signup and view all the answers

In the context of thermodynamics, what does the second law of thermodynamics state about energy transfer or transformation?

The entropy of the universe is constantly increasing Signup and view all the answers

What best describes the relationship between ATP and cellular work?

ATP is used to couple exergonic reactions to endergonic reactions Signup and view all the answers

Which law of thermodynamics states that every energy transfer or transformation increases the disorder (entropy) of the universe?

The second law Signup and view all the answers

What is the name of the study of energy transformations in matter?

Bioenergetics Signup and view all the answers

What is the name of the energy converted to thermal energy and released as heat during energy transformation?

Exothermic energy Signup and view all the answers

What is the unstoppable trend mentioned in the text?

Randomization of the universe Signup and view all the answers

What does entropy refer to?

Measure of disorder in a system Signup and view all the answers

What is the role of energy in ecosystems in relation to entropy?

Energy increases entropy in ecosystems Signup and view all the answers

What is the name for the measure of molecular disorder used by scientists?

Entropy Signup and view all the answers

What is the first law of thermodynamics?

Energy can be transferred and transformed, but not created or destroyed Signup and view all the answers

How do enzymes speed up metabolic reactions?

By decreasing the activation energy Signup and view all the answers

What is bioenergetics?

The study of energy flow through living systems Signup and view all the answers

What does the free-energy change of a reaction tell us?

The direction of the reaction Signup and view all the answers

What is the system in the context of thermodynamics?

The specific part under study Signup and view all the answers

Which law of thermodynamics predicts that living systems increase the entropy of their surroundings?

Second law of thermodynamics Signup and view all the answers

What is the name of the useful function that measures the portion of a system’s energy that can perform work when temperature and pressure are uniform throughout the system?

Gibbs free energy Signup and view all the answers

What is the name of the measure of molecular disorder used by scientists?

Entropy Signup and view all the answers

What does a negative $ΔG$ value indicate about a chemical reaction?

The reaction is exergonic Signup and view all the answers

What is the relationship between the increase in biological order over time and the second law of thermodynamics?

It is consistent with the second law of thermodynamics Signup and view all the answers

What is the name of the energy converted to thermal energy and released as heat during energy transformation?

Heat energy Signup and view all the answers

What is the name of the study of energy transformations in matter?

Thermodynamics Signup and view all the answers

What is the name of the energy transformation illustrated by the flow of energy into ecosystems in the form of light and exiting as heat?

Thermal energy transformation Signup and view all the answers

What does the depletion of chemical energy in organisms account for?

Heat generated during metabolism Signup and view all the answers

What is the name of the unstoppable trend mentioned in the text?

Increase in disorder Signup and view all the answers

What is the name of the role of energy in ecosystems in relation to entropy?

Entropy increase Signup and view all the answers

What is the name of the energy converted to kinetic energy by biological processes, contributing to an increase in disorder?

Chemical energy Signup and view all the answers

What is the equation to calculate the free-energy change (ΔG) for a chemical reaction?

$ΔG = ΔH - TΔS$ Signup and view all the answers

What does a negative ΔG value indicate about the free energy and stability of the final state?

Loss of free energy and increased stability Signup and view all the answers

What is the state of maximum stability in a system?

Equilibrium Signup and view all the answers

How are chemical reactions classified based on their free-energy changes?

Exergonic (release of free energy) or endergonic (absorption of free energy) Signup and view all the answers

What does free energy serve as a measure of in a system?

System's instability and tendency to change to a more stable state Signup and view all the answers

What enables cells to release chemical energy from food molecules and use it to power life processes?

Exergonic reactions Signup and view all the answers

What is the name of the study of energy transformations in matter?

Bioenergetics Signup and view all the answers

When can a system put thermal energy to work?

When it is away from equilibrium Signup and view all the answers

What is the role of energy in ecosystems in relation to entropy?

Energy transformation increases entropy Signup and view all the answers

What is consistent with the laws of thermodynamics?

Energy cannot be created or destroyed Signup and view all the answers

What does the loss of usable energy as heat to the surroundings do to the universe?

Decreases the usable energy in the universe Signup and view all the answers

What does entropy refer to?

Measure of molecular disorder Signup and view all the answers

What is the name for the series of defined steps that alter specific molecules, catalyzed by enzymes?

Metabolic pathways Signup and view all the answers

What is the name of the study of how energy flows through living organisms?

Bioenergetics Signup and view all the answers

What is the potential energy available for release in a chemical reaction, high in complex molecules like glucose?

Chemical energy Signup and view all the answers

What is the capacity to cause change and exists in various forms, including kinetic, thermal, light, and potential energy?

Energy Signup and view all the answers

What is the name for the measure of molecular disorder used by scientists?

Entropy Signup and view all the answers

What law of thermodynamics states that every energy transfer or transformation increases the entropy of the universe?

Second law Signup and view all the answers

What is the name for the totality of an organism’s chemical reactions and is an emergent property of life?

Metabolism Signup and view all the answers

What do catabolic pathways release energy by?

Breaking down complex molecules Signup and view all the answers

What do anabolic pathways do?

Consume energy to build complicated molecules from simpler ones Signup and view all the answers

What is the name for the unstoppable trend mentioned in the text?

Increase in entropy Signup and view all the answers

What is the name of the energy transformation illustrated in Figure 8.2?

Chemical energy conversion Signup and view all the answers

What does the transformation of chemical energy in biological systems produce as waste products?

Carbon dioxide and water Signup and view all the answers

Study Notes

Understanding Free Energy and Its Role in Biochemical Reactions

Free-energy change (ΔG) for a chemical reaction can be calculated using the equation ΔG = ΔH - TΔS, where ΔH is the change in enthalpy, ΔS is the change in entropy, and T is the absolute temperature in Kelvin.
ΔG value is dependent on conditions such as pH, temperature, and concentrations of reactants and products.
Processes with a negative ΔG are spontaneous, and only these processes are observed in nature.
Spontaneous processes result in a decrease in the system's free energy, which can be harnessed by the cell to perform work.
ΔG represents the difference between the free energy of the final and initial states, and a negative ΔG indicates a loss of free energy and increased stability in the final state.
Free energy serves as a measure of a system's instability and tendency to change to a more stable state.
Equilibrium is a state of maximum stability, and systems at equilibrium have the lowest possible free energy.
Systems never spontaneously move away from equilibrium, and a system at equilibrium cannot perform work.
Chemical reactions are classified as exergonic (release of free energy) or endergonic (absorption of free energy) based on their free-energy changes.
Exergonic reactions occur spontaneously due to the release of free energy.
Free energy is harnessed to perform work in spontaneous changes, such as gravitational motion and diffusion.
Understanding free energy is crucial in the study of metabolism to determine which reactions can supply energy for cellular work.

Metabolism and Energy in Living Organisms

The first law of thermodynamics states that energy can be transferred and transformed, but not created or destroyed
The second law of thermodynamics states that every energy transfer or transformation increases the entropy of the universe
Metabolism is the totality of an organism’s chemical reactions and is an emergent property of life
Metabolic pathways are a series of defined steps that alter specific molecules, catalyzed by enzymes
Catabolic pathways release energy by breaking down complex molecules, such as in cellular respiration
Anabolic pathways consume energy to build complicated molecules from simpler ones
Energy is the capacity to cause change and exists in various forms, including kinetic, thermal, light, and potential energy
Chemical energy is the potential energy available for release in a chemical reaction; high in complex molecules like glucose
Catabolic reactions release energy by breaking bonds and forming new ones, resulting in lower-energy breakdown products
The transformation of chemical energy also occurs in biological systems, producing carbon dioxide and water as waste products
These principles apply to bioenergetics, the study of how energy flows through living organisms
A basic knowledge of energy is necessary to understand how the living cell works

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Description

Test your knowledge of free energy and its role in biochemical reactions with this quiz. Explore the factors affecting free-energy change, the spontaneity of processes, and the relationship between free energy and stability. Gain a deeper understanding of how free energy impacts cellular work and metabolism.