Name: polymer chains and their properties
Uploaded: 2023-04-30T18:28:47.000Z
Duration: 2 min 34 s
Channel: JoVE

K12 Standards

Florida Department of Education

High School

Life Science

SC.912.L.18

SC.912.L.18.1

Polymers

Ein Polymer ist eine Kette von kleinen Molekülen, sogenannten Monomeren, die durch kovalente Bindungen zusammengehalten werden. Organismen können biologische Polymere synthetisieren, oder Wissenschaftler können Polymere im Labor synthetisieren.
Zu den natürlichen Polymeren gehören die DNA, das genetische Material, das in allen lebenden Organismen vorkommt, sowie Proteine, Polysaccharide und Lipide, die Bausteine des Lebens.
Kunststoffe gehören zu den gebräuchlichsten synthetischen Polymeren und umfassen Nylon, Polyethylen und Teflon.
Der Prozess, bei dem sich Monomere miteinander verbinden, um ein größeres Molekül zu bilden, wird als Polymerisation bezeichnet. Monomere polymerisieren durch zwei unterschiedliche Reaktionsmechanismen, Kondensation und Addition.
Bei der Kondensationspolymerisation binden sich zwei Monomere mit einem reaktiven Wasserstoffatom bzw. einer Hydroxylgruppe aneinander, wobei Wasser als Nebenprodukt freigesetzt wird. Die meisten natürlichen Polymere entstehen durch Kondensationsreaktionen.
Neben der Polymerisation werden Monomere mit Kohlenstoff-Kohlenstoff-Doppelbindungen aneinander addiert, um ein Polymer zu bilden, ohne dass durch die Freisetzung von Atomen ein Nebenprodukt entsteht. 
Polymere, die aus der gleichen Art von Monomeren bestehen, werden als Homopolymere bezeichnet, und Polymere, die aus verschiedenen Arten von Monomeren bestehen, werden als Heteropolymere bezeichnet. Cellulose, das am häufigsten vorkommende natürliche Polymer, ist ein Homopolymer von Glukose, während Agarose, ein Polymer marinen Ursprungs, ein Heteropolymer aus Galaktose und 3,6-Anhydro-L-Galactopyranose ist.
Polymere haben je nach Art ihrer Monomere unterschiedliche Strukturen. Lineare Polymere sind lange Ketten von Monomeren. Zum Beispiel ist Cellulose ein lineares Polymer, das durch Beta-1,4-glykosidische Bindungen zusammengehalten wird. 
Verzweigte Polymere haben Ketten, die sich von der Hauptkette abspalten, wie z. B. Amylopektin, ein Bestandteil der Stärke, der sich nach 24 bis 30 Monomeren durch alpha-1,6-glykosidische Bindungen verzweigt.
Vernetzte Polymere haben zwei oder mehr Ketten, die an mehreren Punkten wie einer Leiter zusammengehalten werden, wie z. B. ein synthetisch konstruiertes Silikonleiterpolymer, oder bilden ein komplexes Netzwerk miteinander verbundener Ketten – wie das Gel, das von Pektinen in Gelees und Marmeladen gebildet wird.

polymere

Das Wort Polymer leitet sich von den griechischen Wörtern „poly“ für „viele“ und „mer“ für „Teile“ ab. Polymere sind lange Molekülketten, die aus sich wiederholenden Einheiten kleinerer Moleküle, sogenannten Monomeren, bestehen. Sie kommen entweder natürlich vor, wie etwa DNA und Proteine, oder können synthetisch hergestellt werden, wie etwa Kunststoffe. Sie weisen unterschiedliche Strukturmerkmale auf, wie z. B. lineare Ketten, verzweigte Ketten oder komplexe Netzwerke, die zu den Eigenschaften beitragen, die sie aufweisen. Darüber hinaus definieren funktionelle Gruppen, die auf einem Polymer vorhanden sein können, dessen Eigenschaften weiter. Die einzelnen Einheiten eines Polymers werden durch stabile kovalente Bindungen zusammengehalten, die entweder durch Additions- oder Kondensationspolymerisation entstehen. Additionspolymerisation Eine zusätzliche Polymerisation findet statt, wenn die an der Reaktion beteiligten Monomere Doppelbindungen aufweisen. Diese Reaktion erfordert die Anwesenheit eines externen Moleküls, das über ein ungepaartes Valenzelektron verfügt, um die Reaktion einzuleiten. Dieses ungepaarte Elektron ist hochreaktiv und geht eine Bindung mit einer der Doppelbindungen in einem Monomer ein, was dazu führt, dass das Monomer ein ungepaartes Valenzelektron hat. Dieses ungepaarte Valenzelektron verbindet sich dann mit einem anderen Monomer mit Doppelbindungen, was zu einer Kettenreaktion führt, bei der das Molekül weitere Monomere mit Doppelbindungen hinzufügt. Dadurch entsteht eine Kette von Monomeren, wobei das zuletzt hinzugefügte über ein ungepaartes Valenzelektron verfügt. Diese Additionsreaktion setzt sich fort, bis zwei Ketten mit ungepaarten Elektronen miteinander reagieren und eine Bindung bilden. Dadurch werden alle ungepaarten Valenzelektronen eliminiert, was zum Abbruch der Reaktion führt. Kondensationspolymerisation Die Kondensationspolymerisation, auch Stufenwachstumspolymerisation genannt, erfordert einen Katalysator, etwa eine Säure oder ein Enzym, und die Monomere müssen mindestens zwei reaktive funktionelle Gruppen, etwa Amine oder Carbonsäuren, aufweisen. Funktionelle Gruppen an Monomeren reagieren miteinander unter Bildung von Bindungen wie Ester- oder Amidbindungen und gehen mit dem Verlust eines kleinen Moleküls wie Wasser einher. Die Kondensationspolymerisation ist im Vergleich zur Additionspolymerisation eine langsamere Reaktion und erfordert in vielen Fällen die Anwesenheit von Wärme. Dieser Text wurde angepasst von <a href="https://openstax.org/books/chemistry-2e/pages/Hydrocarbons">Openstax, Chemistry 2e, Chapter 20.1: Hydrocarbons</a>.

Polymere

Das Wort Polymer leitet sich von den griechischen Wörtern "poly" ab, was "viele" bedeutet, und "mer", was "Teile" bedeutet. ...

Education

Lehre

JoVE Core

Cell Biology

Zellbiologie

Unit 1

Einheit 1

Biochemistry of the Cell

Biochemie der Zelle

KEY TERMS AND CONCEPTS

KERNBEGRIFFE UND KONZEPTE

polymer chains and their properties

Polymers are large molecules made from repeating units called monomers. These long chains can form many common materials. Their structure helps explain why different polymers can behave in different ways.

Polymers can be built in more than one way. Some form by addition polymerization, where monomers join together directly. Others form by condensation polymerization, which releases a small molecule as the chain grows.

The type of polymer affects its properties and uses. Some polymers are strong and flexible, while others are more rigid. Many everyday materials are made from polymers, so understanding how they form helps explain the materials people use every day.

Polymer Chains and Their Properties

the periodic table and organismal elements

the-periodic-table-and-organismal-elements

Elements in the Human Body and Periodic Table

Elements are the smallest units of matter that cannot be broken down further by chemical processes. Scientists know 118 elements, but not all of them occur naturally. Only a small number are essential for life, and living matter depends mostly on carbon, nitrogen, hydrogen, and oxygen. The periodic table organizes elements by their physical and chemical properties. Each square shows the element name, chemical symbol, atomic number, and atomic weight. The atomic number is the number of protons...

functional groups

Functional Groups in Organic Molecules

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types of chemical bonds

Chemical Bonds and How Atoms Join

Chemical bonds hold atoms together and help explain how different substances form. In chemistry, the main bond types are ionic bonds, covalent bonds, and metallic bonds. Ionic bonds form when electrons move from one atom to another. Covalent bonds form when atoms share electrons. Metallic bonds occur in metals, where electrons are held in a shared arrangement that gives metals their characteristic behavior. Understanding these bond types helps students compare how atoms connect in different...

noncovalent attractions in biomolecules

Biomolecule Interactions Without Covalent Bonds

Biomolecules often stay together through noncovalent attractions instead of covalent bonds. These weaker interactions help molecules recognize each other and form structures needed for life. The main noncovalent attractions are hydrogen bonds, electrostatic interactions, van der Waals forces, and hydrophobic interactions. Each one works in a different way, but all of them can influence how biomolecules fold, bind, and behave in cells. Hydrogen bonds form when a hydrogen atom is attracted to...

polymers

Polymers are large molecules made from repeating units called monomers. These long chains can form many common materials. Their structure helps explain why different polymers can behave in different ways. Polymers can be built in more than one way. Some form by addition polymerization, where monomers join together directly. Others form by condensation polymerization, which releases a small molecule as the chain grows. The type of polymer affects its properties and uses. Some polymers are...

what are lipids?

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How Lipid Molecules Are Built

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chemistry of carbohydrates

Carbohydrate Structure and Bonding

Carbohydrates are built from sugar units and the bonds that link them. Their chemistry explains how simple sugars join to form larger molecules. It also helps show why carbohydrates have different structures and functions. The video focuses on the main sugar types found in carbohydrates. These include monosaccharides, disaccharides, and polysaccharides. Monosaccharides are single sugar units. Disaccharides contain two sugar units, while polysaccharides are long chains of many sugar units. The...

nucleic acids

DNA and RNA in Cells

DNA and RNA are nucleic acids that help store and use genetic information in cells. They are key molecules in biology and are often studied together because they work as a pair in living systems. Nucleic acids are built from repeating units called nucleotides. Each nucleotide has a sugar, a phosphate group, and a nitrogenous base. The order of these bases carries the genetic code. There are two main nucleic acids: DNA, or deoxyribonucleic acid, and RNA, or ribonucleic acid. DNA usually stores...

protein and protein structures

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Proteins are essential molecules in living things, and their shape affects how they work. Protein structure is described at several levels, including primary, secondary, tertiary, and quaternary structure. These levels help explain how a protein is built and how its final form supports its job. Primary structure is the sequence of amino acids in a protein. Secondary structure forms when parts of the chain fold into regular patterns. Tertiary structure is the overall three-dimensional shape of...

ph regulation in cells

Cell pH and Organelle Balance

Cell pH and organelle balance are essential for normal cell function. pH affects protein shape and activity, the charge on cell membranes, and many metabolic reactions inside the cell. Cells also use the proton motive force, which is the energy stored in a proton gradient, to make ATP, the cell’s main energy molecule. The cytosol, or fluid inside the cell, is usually slightly more acidic than the fluid outside the cell. Even so, cells must stop the cytosol from becoming too acidic. They use...

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Cell Chemistry: Water, Ions, and Molecules

Cell chemistry explains the substances that make cells work. Water is the main component of cells, and it supports the chemical reactions that keep life going. Cells also contain organic molecules, which are carbon-based compounds, and inorganic ions, which are charged particles needed for cell function. Organic molecules in cells include carbohydrates, lipids, proteins, and nucleic acids. These molecules have different roles, but together they build cell structures, store energy, and carry...

key terms and concepts

Learn how polymers are built from repeating monomers and how addition and condensation polymerization shape the properties of everyday materials.

Polymer Chains and Their Properties | JoVE K12

cell biology

JoVE Core Zellbiologie veranschaulicht komplexe zelluläre Prozesse in leicht verständlichen und dennoch umfassenden animierten Videolektionen. Diese Sammlung konzentriert sich auf die wesentlichen Bestandteile und Funktionen von Zellen, einschließlich Organellen und Membranen, Zelltransport und Zellenergie. Ergänzt wird sie durch Videos von Wissenschaftlern in Aktion, die die Anwendung der Zellbiologie in realen Forschungsexperimenten demonstrieren.

Macromolecules

Biomolecules
Organisms contain a wide variety of organic molecules with numerous functions which depend on the chemical structures and properties of these ...

What are Lipids?

Lipids function as structural components of cellular membranes, in addition to acting as energy reservoirs and signaling molecules. They are thus crucial ...

Structure of Lipids

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Lipid-derived Compounds in the Human Body

Fats and lipids are crucial components in the human body. Some lipid-derived compounds, such as fat-soluble vitamins, eicosanoids, lipoproteins, and ...

Fats as Energy Storage Molecules

Amino acids

Amino acids are the monomers that comprise proteins. Each amino acid has the same fundamental structure, which consists of a central carbon atom, or the ...

Peptide Bonds

A peptide bond covalently attaches amino acids through a dehydration reaction. One amino acid&#39;s carboxyl group and another amino acid&#39;s amino ...

What are Proteins?

Protein and Protein Structures

Protein Organization

Globular Proteins

In organisms, proteins are the most abundant macromolecules. They act as the building blocks of life and play various crucial roles in the body. Proteins ...

Fibrous Proteins

Fibrous proteins are either long and narrow proteins or assemble to form long and thin structures. They contain repetitive units and usually consist of ...

Protein Denaturation

The function of proteins depends on their native three-dimensional structure, which is dictated by the amino acid sequence of the specific protein. ...

Role of Proteins in the Human Body

Proteins are the building block of life. They are also&#160; the most abundant macromolecules with as many diverse roles in the body. They are part of ...

Mechanical Protein Function

Structural Protein Function

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Nucleic Acid Structure

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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

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Noncovalent Attractions in Biomolecules

Describe the basic molecular structures and primary functions of the four major categories of biological macromolecules.

Cellulose and Pectic Polysaccharides

&#160;Every plant cell has a cell wall that protects the cell, provides structural support, and gives the cell shape. Cellulose, the main structural ...

Membrane Carbohydrates

The plasma membrane is a dynamic barrier composed of lipids, proteins, and carbohydrates. It is the epicenter of many cellular processes required for cell ...

Describe the important structural characteristics of monosaccharides, disaccharides, and polysaccharides and explain the functions of carbohydrates in living things.

SC.912.L.18.2

Overview of Fatty Acid Metabolism

Lipids also are sources of energy that power cellular processes. Like carbohydrates, lipids are composed of carbon, hydrogen, and oxygen, but these atoms ...

What are Membranes?

A cell&#39;s plasma membrane demarcates the cell&#39;s borders and determines the nature of its interaction with the environment. Cells exclude certain ...

Membrane Fluidity

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Fluid Mosaic Model

Scientists identified the plasma membrane in the 1890s and its principal chemical components (lipids and proteins) by 1915. The model for plasma membrane ...

Membrane Lipids

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Asymmetric Lipid Bilayer

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Lipids as Anchors

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The Significance of Membrane Transport

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Describe the structures of fatty acids, triglycerides, phospholipids, and steroids. Explain the functions of lipids in living organisms. Identify some reactions that fatty acids undergo. Relate the structure and function of cell membranes.

SC.912.L.18.3

Ligand Binding Sites

Cofactors and Coenzymes

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Enzymes and Activation Energy

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Introduction to Enzyme Kinetics

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Turnover Number and Catalytic Efficiency

The turnover number of an enzyme is the maximum number of substrate molecules it can transform per unit time. Turnover numbers for most enzymes range from ...

Catalytically Perfect Enzymes

The theory of catalytically perfect enzymes was first proposed by W.J. Albery and J. R. Knowles in 1976. These enzymes catalyze biochemical reactions at ...

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Introduction to Mechanisms of Enzyme Catalysis

For many years, scientists thought that enzyme-substrate binding took place in a simple &#34;lock-and-key&#34; fashion. This model stated that the enzyme ...

Ligand Binding and Linkage

Cooperative Allosteric Transitions

Ribozymes

Enzyme Activity

Biological Catalysts

All living organisms continuously perform numerous biochemical reactions to sustain their presence. Most of these reactions require ...

Describe the structures of proteins and amino acids. Explain the functions of proteins in living organisms. Identify some reactions that amino acids undergo. Relate the structure and function of enzymes.

SC.912.L.18.4

Chemiosmosis

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Electron Transport Chain: Complex I and II

The mitochondrial electron transport chain (ETC) is the main energy generation system in the eukaryotic cells. However, mitochondria also produce ...

electron-transport-chain-complex-iii-and-iv

Electron Transport Chain: Complex III and IV

During the electron transport chain, electrons from NADH and FADH2 are first transferred to complexes I and II, respectively. These two complexes then ...

The Electron Transport Chain

The electron transport chain or oxidative phosphorylation is an exothermic process in which free energy released during electron transfer reactions is ...

the-supercomplexes-in-the-crista-membrane

The Supercomplexes in the Crista Membrane

The mitochondrial cristae membrane is the primary site for the oxidative phosphorylation (OXPHOS) process of energy conversion mediated through ...

ATP Synthase: Structure

ATP synthase or ATPase is among the most conserved proteins found in bacteria, mammals, and plants. This enzyme can catalyze a forward reaction in ...

ATP Synthase: Mechanism

In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear ...

The ADP/ATP Carrier Protein

ADP/ATP carrier or AAC protein is the most abundant carrier protein in the inner mitochondrial membrane. It transports large quantities of ADP and ATP, ...

ATP Yield

Cellular respiration produces 30 - 32 ATP per glucose molecule. Although most of the ATP results from oxidative phosphorylation and the electron transport ...

Discuss the use of chemiosmotic gradients for ATP production in chloroplasts and mitochondria.

SC.912.L.18.5

Fermentation

Most eukaryotic organisms require oxygen to survive and function adequately. Such organisms produce large amounts of energy during aerobic respiration by ...

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Biofuels: Producing Ethanol from Cellulosic Material

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
In this experiment, cellulosic material (such as corn stalks, leaves, ...

Discuss the role of anaerobic respiration in living things and in human society.

SC.912.L.18.6

Photosynthesis

Autotrophs

Almost all living organisms on Earth depend on photosynthesis, which is the process that converts sunlight energy into a simple sugar called ...

What is Photosynthesis?

All living organisms on Earth are directly or indirectly dependent on photosynthesis. It is the only biological process that can capture energy from ...

The Anatomy of Chloroplasts

Green algae and plants, including green stems and unripe fruit, harbor specialized organelles called chloroplasts to carry out photosynthesis. They ...

Photosystems

Photosystems are multiprotein complexes that form the functional units of photosynthesis in plants, algae, and cyanobacteria. They are found embedded in ...

The Photochemical Reaction Center

Reaction centers are pigment-protein complexes that initiate energy conversion from photons to chemical entities. Therefore, photochemical reaction center ...

The Antenna Complex

Plants and other photosynthetic organisms comprise pigments capable of absorption of direct sunlight. These pigments are present in the reaction center - ...

the-z-scheme-of-electron-transport-in-photosynthesis

The Z-Scheme of Electron Transport in Photosynthesis

The light reactions of photosynthesis assume a linear flow of electrons from water to NADP+. During this process, light energy drives the splitting of ...

Identify the reactants, products, and basic functions of photosynthesis.

SC.912.L.18.7

A. All living things are composed of four basic categories of macromolecules and share the same basic needs for life.

B. Living organisms acquire the energy they need for life processes through various metabolic pathways (primarily photosynthesis and cellular respiration).

C. Chemical reactions in living things follow basic rules of chemistry and are usually regulated by enzymes.

D. The unique chemical properties of carbon and water make life on Earth possible.

Polymer Chains and Their Properties

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