Name: cell energy loss and entropy
Uploaded: 2023-04-30T10:41:06.000Z
Duration: 1 min 22 s
Channel: JoVE
Description: Cell energy loss and entropy explain why living things need constant energy input. Cells obtain energy, transform it, and use it to do work, but these transfers are never completely efficient. In each transfer, some energy is lost in a form that cannot be used. In many cases, that lost energy is heat energy.

K12 Standards

Louisiana Student Standards for Science

High School

Chemistry

Energy

HS-PS3-1

Entropy within the Cell

Living cells follow the second law of thermodynamics, which states that systems tend to proceed from low entropy-ordered states to high entropy-disordered states without outside input.
For example, the passive transport of concentrated oxygen from the lungs to the less oxygenated blood disperses the oxygen molecules, increasing the entropy of the system.
Cells derive energy from the breakdown of molecules such as glucose. The by-products of the reaction &#8211; carbon dioxide, water, and heat are released into the surroundings, raising its entropy.
Cell survival depends upon highly ordered systems such as DNA and proteins. The formation of these ordered structures causes a decrease in the entropy of the system, which must be accompanied by an equal or greater increase in the entropy of the surroundings.
Single DNA strands are disordered, and their entropy decreases when they reanneal into an ordered double helix structure.
At the same time, energy is released into the surroundings during double helix formation. This energy makes the surroundings more disordered and increases its entropy.

entropy within the cell

A living cell&#39;s primary tasks of obtaining, transforming, and using energy to do work may seem simple. However, the second law of thermodynamics explains why these tasks are harder than they appear. None of the energy transfers in the universe are completely efficient. In every energy transfer, some amount of energy is lost in a form that is unusable. In most cases, this form is heat energy. Thermodynamically, heat energy is defined as the energy transferred from one system to another that is not work. For example, some energy is lost as heat energy during cellular metabolic reactions.
An important concept in physical systems is that of order and disorder. The more energy that is lost by a system to its surroundings, the less ordered and more random the system is. Scientists refer to the measure of randomness or disorder within a system as entropy. High entropy means high disorder and low energy. Molecules and chemical reactions have varying entropy as well. For example, entropy increases as molecules at a high concentration in one place diffuse and spread out.
Living things are highly ordered, requiring constant energy input to be maintained in a state of low entropy. As living systems take in energy-storing molecules and transform them through chemical reactions, they lose some amount of usable energy in the process because no reaction is completely efficient. They also produce waste and by-products that are not useful energy sources. This process increases the entropy of the system&#39;s surroundings. Since all energy transfers result in the loss of some usable energy, the second law of thermodynamics states that every energy transfer or transformation increases the entropy of the universe. Even though living things are highly ordered and maintain a state of low entropy, the entropy of the universe in total is constantly increasing due to the loss of usable energy with each energy transfer that occurs. Essentially, living things are in a continuous uphill battle against this constant increase in universal entropy.
This text is adapted from <a href="https://openstax.org/books/biology-2e/pages/6-3-the-laws-of-thermodynamics">Openstax Biology 2e, Section 6.3</a><a href="https://openstax.org/books/biology-2e/pages/6-3-the-laws-of-thermodynamics"> The Laws of Thermodynamics</a>.

A living cell&#39;s primary tasks of obtaining, transforming, and using energy to do work may seem simple. However, the second law of thermodynamics ...

Education

JoVE Core

Cell Biology

Unit 1

Energy and Catalysis

KEY TERMS AND CONCEPTS

cell energy loss and entropy

Cell energy loss and entropy explain why living things need constant energy input. Cells obtain energy, transform it, and use it to do work, but these transfers are never completely efficient. In each transfer, some energy is lost in a form that cannot be used. In many cases, that lost energy is heat energy.

Cell Energy Loss and Entropy

the first law of thermodynamics

Energy Changes in Cells and Matter

The first law of thermodynamics describes how energy changes form in the universe. The total amount of energy stays constant. Energy can move from one place to another or change into a different form, but it cannot be created or destroyed. These energy changes happen in everyday life. A light bulb changes electrical energy into light energy. A gas stove changes chemical energy in natural gas into heat energy. Plants also carry out a major energy transformation when they convert sunlight energy...

the second law of thermodynamics

Entropy and Spontaneous Change

Entropy helps predict whether a process will happen on its own. Entropy is a measure of randomness or disorder in a system. High entropy means high disorder and low energy. A student’s bedroom is a simple example. If no work is done, the room becomes messy over time. That messy state is highly disordered and has high entropy. To make the room clean again, energy must be added as the student puts things away. That organized state has low entropy. Processes that increase the entropy of the...

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Cell energy loss and entropy explain why living things need constant energy input. Cells obtain energy, transform it, and use it to do work, but these transfers are never completely efficient. In each transfer, some energy is lost in a form that cannot be used. In many cases, that lost energy is heat energy.

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Gibbs Free Energy and Reaction Work

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Cells Stay Out of Equilibrium

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Electron Carriers in Cell Energy Transfer

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key terms and concepts

Learn how cells use energy, lose some as heat, and increase entropy. See why living things must constantly take in energy to stay organized.

Cell Energy Loss and Entropy | JoVE K12

cell biology

JoVE Core Cell Biology illustrates complex cellular processes in easy-to-understand yet comprehensive animated video lessons. This collection focuses on the essential components and functions of cells, including organelles and membranes, cellular transport, and cell energetics. It is complemented by scientist-in-action videos that demonstrate the application of cell biology in real-world research experiments.

Texas Essential Knowledge and Skills

Biology

BIO.11

BIO.11.A

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New York State Science Learning Standards

Life Science

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HS-PS3-4

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HS-PS3-6

Cell Energy Loss and Entropy

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