Name: entropy in food web energy flow
Uploaded: 2019-03-11T09:21:09.000Z
Duration: 53 s
Channel: JoVE

K12 Standards

Alabama Course of Study Science

9-12

Biology

from-molecules-to-organisms-structures-and-processes

From Molecules to Organisms: Structures and Processes

9-12.B.1.5

Second Law of Thermodynamics

熱力学第二法則は 従来の食物網でも説明できます これは、不可逆性の度合いを表すエントロピーが エネルギーの移動や変化と共に、増大することを指しています 第一生産者が太陽からエネルギーを得て 食物となると 少量の熱エネルギーへと変わり 酸素が環境に放出されます 第一消費者が 植物から化学エネルギーを摂取すると 少量の熱エネルギーを放出し、代謝により二酸化炭素を出します 最後に、捕食者が 最初に太陽から受けたエネルギーの わずかばかりを受け取ります 放出された熱エネルギーと代謝による副産物が 環境内のエントロピーを増大させるのです

「カロリーはカロリーである」は熱力学の第二法則に違反しています。」 ニュートリションジャーナル 3 (2004年7月28日):9。[<a href="https://doi.org/10.1186/1475-2891-3-9" target="__blank">ソース</a>]

「平衡から遠く離れた地球システムの熱力学の基本紹介と最大エントロピー生成」 Philosophical Transactions of the Royal Society B: Biological Sciences 365, no. 1545 (2010年5月12日): 1303-15.[<a href="https://doi.org/10.1098/rstb.2009.0310" target="__blank">ソース</a>]

熱力学の第二法則

熱力学の第二法則では、エネルギーが移動し変換されるたび、エントロピー（系内の乱雑さ）が増加するとされています。エネルギーが動かされると、一定量のエネルギーが通常熱として失われ、周囲の乱雑さを増大させます。これは、古典的な食物網でも見られます。草食動物は、植物から化学エネルギーを得て、熱と二酸化炭素を環境に放出します。肉食動物もまた、草食動物が生産した化学エネルギーを得て（そのうち元々太陽の放射エネルギーに相当するものはほんのわずかです）、熱エネルギーと二酸化炭素を周囲に放出します。その結果、食物網の各段階で放出された熱エネルギーやその他の代謝副産物が、そのエントロピーを増大させます。
 
 <h4>熱力学の第二法則</h4>
 
 熱力学の第二法則では、エネルギーが移動し変換されるたび、エントロピー（系内の乱雑さ）が増加するとされています。あらゆるエネルギーの移動において、一定量のエネルギーが通常は熱という使用不可能な形で失われます。この熱エネルギーは、ぶつかった分子の速度を一時的に上げることができます。このように、系が周囲に失うエネルギーが多いほど、系の秩序が乱れ、乱雑になります。
 
 熱力学の第一法則と同様に、熱力学の第二法則も古典的な食物網の中に見られます。植物などの一次生産者が太陽からのエネルギーを受けて食物を作ると、少量のエネルギーが使えない熱に変換され、酸素と一緒に環境中に放出されます。
 
 草食動物などの一次消費者もまた、植物から化学エネルギーを獲得すると、代謝を通して二酸化炭素と一緒に少量の熱エネルギーを放出します。肉食動物もまた、草食動物が生産した化学エネルギーを獲得し（このうち太陽由来の放射エネルギーはごく一部である）、二酸化炭素とともに熱エネルギーを周囲に放出します。このように、放出された熱エネルギーやその他の代謝副産物によって、食物網内のエントロピーは増大しています。

熱力学の第二法則は、エントロピー、つまりシステム内の無秩序の量は、エネルギーが移動または変換されるたびに増加すると述べています。...

Education

JoVE Core

生物学

Cellular Processes

細胞プロセス

Metabolism

代謝

KEY TERMS AND CONCEPTS

主要用語と概念

entropy in food web energy flow

The Second Law of Thermodynamics explains why entropy increases as energy moves through a system. Entropy means the amount of disorder in a system. Each time energy is transferred or transformed, some energy is lost as unusable heat. That heat can raise the motion of nearby molecules for a short time and make the surroundings less ordered and more random.

This idea also appears in a food web. Primary producers, such as plants, take in energy from the sun and make food. During this process, some energy becomes unusable heat and is released into the environment with oxygen. When primary consumers, like herbivores, eat plants, they harvest chemical energy and also give off heat and carbon dioxide during metabolism.

Carnivores then use the chemical energy made by herbivores. Only a fraction of that energy still traces back to the original radiant energy from the sun. At each step, heat energy and other metabolic by-products are released into the surroundings. As a result, entropy increases across the food web.

Entropy in Food Web Energy Flow

what is metabolism?

Metabolism, Energy, and Cell Reactions

Metabolism is the set of chemical reactions that happen in a cell. It includes anabolism, which builds molecules, and catabolism, which breaks them down. These reactions help cells manage energy and keep life processes running. Cells use metabolism to turn food into energy, make cell parts, and remove waste products. Food stores potential energy in the bonds between atoms. Catabolic pathways break large food molecules into smaller ones and release that energy. Anabolic pathways use that energy...

first law of thermodynamics

Energy Flow in a Food Web

Energy flow in a food web shows the First Law of Thermodynamics in action. Energy cannot be created or destroyed. It can only change form as it moves through living things and the environment. Sunlight is the starting point. Plants capture radiant energy from the sun during photosynthesis and turn it into chemical energy stored in complex carbohydrates. At the same time, oxygen is released into the atmosphere. Herbivores eat the plants and use those sugars during digestion. The energy is...

second law of thermodynamics

The Second Law of Thermodynamics explains why entropy increases as energy moves through a system. Entropy means the amount of disorder in a system. Each time energy is transferred or transformed, some energy is lost as unusable heat. That heat can raise the motion of nearby molecules for a short time and make the surroundings less ordered and more random. This idea also appears in a food web. Primary producers, such as plants, take in energy from the sun and make food. During this process,...

kinetic energy

Motion as a Source of Energy

Kinetic energy is the energy of motion. It appears when an object is moving and can do work or cause change. A waterfall is one clear example. Water behind a dam has potential energy, but when it rushes downward, that moving water has kinetic energy. When the water reaches the bottom and stops moving, its energy can become potential energy again. Kinetic energy also shows up in living systems. Plants absorb light particles, called photons, which move very fast and help create chemical energy...

potential energy

Stored Energy in Motion and Bonds

Stored energy in motion and bonds is called potential energy. It depends on the structure of an object or the position of matter in space. Raising a kettlebell changes its location and increases its potential energy. A stretched rubber band also stores potential energy, which can later change into kinetic energy. Chemical bonds between atoms hold another form of stored energy called chemical energy. These bonds involve attractive forces, and that energy can change into other forms during a...

free energy

Gibbs Free Energy in Chemical Reactions

Gibbs free energy is a measure of useful energy that can be taken from a chemical reaction to do work. It is written as G and named for scientist Gibbs, who discovered it. This energy is what remains after entropy is considered. A reaction can either take in energy or release it. Reactions that absorb energy are called endergonic reactions. Reactions that release energy are called exergonic reactions. The direction of energy flow helps show which type of reaction is happening. Plants carry...

activation energy

How Catalysts Lower Reaction Barriers

Activation energy is the minimum energy a chemical reaction needs to keep going. When the activation energy is higher, the reaction usually happens more slowly. Adding heat can speed the reaction because molecules move faster and collide more often. As reactants collide, bonds break and the reaction moves through an uphill phase. That step creates the transition state, which is an unstable, high-energy state of the reactants. After that, new bonds form, products appear, and free energy is...

hydrolysis of atp

ATP Breakdown and Energy Release

ATP breakdown releases energy for cell work. Adenosine triphosphate, or ATP, can lose one or two phosphate groups when water is added. This hydrolysis reaction is exergonic, which means it releases energy that the cell can use. When one phosphate group is removed, ATP becomes ADP, or adenosine diphosphate. Inorganic phosphate is also released. ADP can then be hydrolyzed again to form AMP, or adenosine monophosphate, after a second phosphate group is removed. ATP has a clear structure. It is...

phosphorylation

Phosphorylation and Protein Control

Phosphorylation helps control how proteins work in cells. It is the addition or removal of phosphate groups, and it is the most common chemical change that regulates cellular processes. These changes can alter a protein’s structure, activity, stability, location inside the cell, and interactions with other proteins. During phosphorylation, protein kinases move the terminal phosphate group from ATP to a specific amino acid side chain on a target protein. The amino acids most often...

induced-fit model

How Enzymes Adjust to Their Substrates

Enzymes speed up many chemical reactions in cells. They are biological catalysts, so they increase reaction speed without being consumed or permanently changed. They do this by lowering the activation energy needed to turn reactants into products. Enzymes are proteins that usually work by binding to a substrate, which is the reactant molecule they act on. They show substrate specificity, meaning they bind only certain substrates. This specificity depends mainly on the shape and chemical...

enzyme kinetics

Substrate Effects on Enzyme Rates

Enzyme kinetics examines how enzymes change the rate of a reaction. Enzymes speed reactions by lowering the activation energy of the reactants. The reaction rate is the speed at which an enzyme turns reactants into products, and it can be affected by several factors, including the number of available reactants. Scientists often study enzyme kinetics in a test tube with a fixed amount of enzyme. When more substrate, or reactant, is added, the reaction rate increases because the enzyme can make...

enzyme inhibition

Competitive vs Noncompetitive Inhibitors

Enzyme inhibitors are molecules that reduce enzyme activity by binding to enzymes. Cells use these inhibitors to help regulate normal enzyme function. Drugs and toxins can also block enzymes and change how they work. Some inhibitors bind at the active site, which is the part of the enzyme where the substrate normally fits. Competitive inhibitors do this by occupying the active site and preventing the substrate from binding. If the substrate concentration becomes high enough, it can outcompete...

feedback inhibition

How Cells Control Product Buildup

Cells use enzymes to run biochemical reactions and make the products they need. These reactions are happening constantly, and enzymes speed them up so they happen fast enough to matter. Enzyme activity also has to be regulated. Cells need the right amounts of starting materials, intermediate metabolites, and final products. If these substances build up too much or drop too low, the cell can be harmed. That is why cells use control systems to keep metabolic levels balanced. One important...

allosteric regulation

Allosteric Control of Enzyme Speed

Allosteric control changes enzyme speed when a molecule binds to a site other than the active site. That alternate binding spot is called an allosteric site. An enzyme can have more than one allosteric site. This type of control can raise or lower enzyme activity. Many enzymes with allosteric control are metabolic enzymes. They help with the breakdown or the building of specific molecules in cells. In allosteric inhibition, the effector molecule causes a shape change that lowers the enzyme's...

cofactors and coenzymes

Enzyme Helpers: Metals, Vitamins, and More

Enzyme helpers are needed for many enzymes to work properly. These helpers fall into two groups: cofactors and coenzymes. Cofactors are metallic ions, while coenzymes are non-protein organic molecules. Both can be tightly bound to an enzyme or attach only when the substrate binds. Cofactors are common in mature proteins, appearing in about 30% of them. They are often added as the enzyme folds and help with catalytic activity. Magnesium is one important cofactor, and it is needed by more than...

key terms and concepts

Explore how the Second Law of Thermodynamics increases entropy as energy moves through food webs, from plants to herbivores and carnivores.

Entropy in Food Web Energy Flow | JoVE K12

JoVE Core series brings biology to life through over 300 concise and easy-to-understand animated video lessons that explain key concepts in biology, plus more than 150 scientist-in-action videos that show actual research experiments conducted in today’s laboratories.

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JoVE Core シリーズは、生物学の重要な概念を説明する 300 を超える簡潔でわかりやすいアニメーション ビデオ レッスンに加え、今日の研究室で行われる実際の研究実験を示す 150 以上の科学者の活動ビデオを通じて、生物学に命を吹き込みます。

Next Generation Science Standards

High School

Life Science

ecosystems-interactions-energy-and-dynamics

Ecosystems: Interactions, Energy, and Dynamics

HS-LS2-4

Georgia Standards of Excellence

Ecology

SEC4.

SEC4.c

myJoVE Corporation

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Cells are the smallest and basic units of life, whether it is a single cell that forms the entire organism, e.g., in a bacterium or trillions of them, ...

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Prokaryotic Cells

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Cytoplasm

The cytoplasm consists of organelles and a framework of protein scaffolds called the cytoskeleton suspended in an aqueous solution, the cytosol. The ...

The Nucleus

The nucleus is a membrane-bound organelle that acts as a control center in a eukaryotic cell. It contains chromosomal DNA, which controls gene expression ...

Endoplasmic Reticulum

Endoplasmic ReticulumThe endoplasmic reticulum (ER) is an extensive network of membranous sacs and tubules in eukaryotic cells, continuous with the outer ...

Ribosomes

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Golgi Apparatus

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Lysosomes

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Peroxisomes

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Introduction to the Cytoskeleton

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overview-of-myosin-structure-and-function

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Microtubules

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The Extracellular Matrix

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Tissues

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Plant Cell Wall

The plant cell wall gives plant cells shape, support, and protection. As a cell matures, its cell wall specializes according to the cell type. For ...

Plasmodesmata

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ATP Energy Storage and Release

ATP and Macromolecule Synthesis

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1. Engage in evidence-based argument to relate a cell's function to the structure, function, and diversity of its components. Examples: Muscle cells have a large number of mitochondria, which create energy for contraction in the form of ATP. Some plant cells have a large vacuole which is used for storage and transport of excess nutrients in changing environments.

9-12.B.1.1

What is Gene Expression?

A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is comprised&#160; of nucleotides and proteins are ...

RNA Structure

The basic structure of RNA consists of a string of ribonucleotides attached by phosphodiester bonds. Although most RNA is single-stranded, it can form ...

Types of RNA

Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse ...

Transcription

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Bacterial RNA Polymerase

Eukaryotic RNA Polymerases

General Transcription Factors

Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of ...

RNA Polymerase II Accessory Proteins

Transcription Elongation Factors

pre-mrna-processing-modification-of-pre-mrna-ends

Pre-mRNA Processing: Modification of pre-mRNA Ends

In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or ...

Pre-mRNA Processing: RNA Splicing

Chromatin Structure and RNA Splicing

Alternative RNA Splicing

Nuclear Export of mRNA

Transfer RNA Synthesis

Ribosomal RNA Synthesis

The Nucleolus

Additional Subnuclear Structures

Translation

Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes ...

tRNA Activation

Initiation of Translation

Termination of Translation

Improving Translational Accuracy

prokaryotic-transcriptional-activators-and-repressors

Prokaryotic Transcriptional Activators and Repressors

Nonsense-mediated mRNA Decay

The Eukaryotic Promoter Region

Molecular Chaperones and Protein Folding

Co-activators and Co-repressors

The Proteasome

Master Transcription Regulators

Regulated Protein Degradation

Regulated mRNA Transport

Proteins: From Genes to Degradation

mRNA Stability and Gene Expression

Cell Specific Gene Expression

MicroRNAs

MicroRNA (miRNA) are short, regulatory RNA transcribed from introns (non-coding regions of a gene) or intergenic regions (stretches of DNA present between ...

regulation-of-expression-occurs-at-multiple-steps

Regulation of Expression Occurs at Multiple Steps

Small interfering RNAs (siRNA)

Cis-regulatory Sequences

lncRNA - Long Non-coding RNAs

cooperative-binding-of-transcription-regulators

Cooperative Binding of Transcription Regulators

Epigenetic Regulation

Epigenetic changes alter the physical structure of the DNA without changing the genetic sequence and often regulate whether genes are turned on or off. ...

2. Obtain and evaluate information to explain the role of DNA and RNA in transcription and translation leading to protein synthesis and cellular function.

9-12.B.1.2

Nucleic Acids and Nucleotides

Nucleic acids are the most important macromolecules for the continuity of life. They carry the cell&#39;s genetic blueprint and have instructions for its ...

Nucleic Acid Structure

The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group ...

a. Use a model to describe the structure and sequence of DNA, including nucleotide structure, base pairing, and the structure of the helix.

9-12.B.1.2.a

Entropy in Food Web Energy Flow

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