Biological Sciences
Organic Molecules
Organic molecules are carbon-based compounds that are essential for life. They form the building blocks of living organisms and are involved in various biological processes such as energy production, growth, and reproduction. Examples of organic molecules include carbohydrates, lipids, proteins, and nucleic acids.
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9 Key excerpts on "Organic Molecules"
eBook - PDF- Nina Parker, Mark Schneegurt, Anh-Hue Thi Tu, Brian M. Forster, Philip Lister(Authors)
- 2016(Publication Date)
- Openstax(Publisher)
All of these molecules, called biomolecules because they are part of living matter, contain carbon, which is the building block of life. Carbon is a very unique element in that it has four valence electrons in its outer orbitals and can form four single covalent bonds with up to four other atoms at the same time (see Appendix A). These atoms are usually oxygen, hydrogen, nitrogen, sulfur, phosphorous, and carbon itself; the simplest organic compound is methane, in which carbon binds only to hydrogen (Figure 7.3). As a result of carbon’s unique combination of size and bonding properties, carbon atoms can bind together in large numbers, thus producing a chain or carbon skeleton. The carbon skeleton of Organic Molecules can be straight, branched, or ring shaped (cyclic). Organic Molecules are built on chains of carbon atoms of varying lengths; most are typically very long, which allows for a huge number and variety of compounds. No other element has the ability to form so many different molecules of so many different sizes and shapes. Chapter 7 | Microbial Biochemistry 285 Figure 7.3 A carbon atom can bond with up to four other atoms. The simplest organic molecule is methane (CH 4 ), depicted here. Molecules with the same atomic makeup but different structural arrangement of atoms are called isomers. The concept of isomerism is very important in chemistry because the structure of a molecule is always directly related to its function. Slight changes in the structural arrangements of atoms in a molecule may lead to very different properties. Chemists represent molecules by their structural formula, which is a graphic representation of the molecular structure, showing how the atoms are arranged. Compounds that have identical molecular formulas but differ in the bonding sequence of the atoms are called structural isomers.
- Jason Birkett, John Lester(Authors)
- 2018(Publication Date)
- CRC Press(Publisher)
Chapter 8Biological molecules
8.1 Introduction
The existence of a cell depends upon its structural components, which maintain its physical integrity, and its functional components, which control its growth, metabolism and reproduction and which regulate these processes. In a great many instances structural and functional roles are closely integrated, even in the simplest cell.The highly ordered, but extremely complex nature of living cells is due to the great variety of organic compounds which may be formed, inherent in the chemical properties of carbon itself. Its ability to form four covalent bonds with other atoms and itself, generating long carbon chains, gives rise to an almost limitless number of possible compounds, including macromolecules with molecular weights as high as 100 million. In all cases, these macromolecules are formed from the linkage, in a series, of smaller molecules, termed monomers, and hence are called polymers. Even if constructed from a pool containing a relatively small number of different types of monomer molecules the number of different possible sequences of these subunits is theoretically very large indeed. If only a small fraction of all of the possible combinations of monomers were to be associated with a distinct structural or functional characteristic of the polymer molecule, this number would be more than sufficient to account for the enormous diversity and complexity of living organisms. There are, however, a large number of characteristics common to all cells, irrespective of their origins, which is indicative of a moderately consistent selection of only a few of the possible combinations in each case, suggesting that cellular chemistry is organized and regulated in a highly precise manner.There is, in addition to the macromolecules, a great variety of other organic compounds which are important by virtue of their role as nutrients and intermediary metabolites. However, this chapter focuses only on those which are unique and integral components of cells—the macromolecules.
- Aniruddha Datta, Edward R. Dougherty(Authors)
- 2018(Publication Date)
- CRC Press(Publisher)
2 Review of Organic Chemistry In this chapter, we provide a brief introduction to organic chemistry. The chemical properties of biological molecules play a crucial role in making all known life possible and so any discussion of molecular biology would have to necessarily include some discussion of organic chemistry. Although the dis-cussion here is far from exhaustive, it is essentially self-contained and should provide a good introduction to anyone who has had some exposure to basic chemistry in the past. For a more detailed treatment, the reader is referred to [2]. Matter is made up of combinations of elements — substances such as hydro-gen or carbon that cannot be broken down or converted into other substances by chemical means. An atom is the smallest particle of an element that still retains its distinctive chemical properties. Molecules are formed by two or more atoms of the same element or of different elements combining together in a chemical fashion. An atom is made up of three kinds of subatomic parti-cles: protons (mass = 1, charge = +1); neutrons (mass = 1, charge = 0); and electrons (mass 0, charge = − 1). Protons and neutrons reside in the nucleus of the atom while electrons revolve around the nucleus in certain orbits. Each element has a fixed number of protons in the nucleus of each of its atoms and this number is referred to as the atomic number . We next list a few elements that occur over and over again in Organic Molecules, along with their atomic numbers: hydrogen (H) has an atomic number of 1; oxygen (O) has an atomic number of 8; carbon (C) has an atomic number of 6; nitrogen (N) has an atomic number of 7; phosphorous (P) has an atomic number of 15; sodium (Na) has an atomic number of 11; and calcium (Ca) has an atomic number of 20. The total number of protons and neutrons in the nucleus of an atom of a particular element is referred to as its atomic weight . The hydrogen atom has only one proton and one electron and so its atomic weight is 1.
eBook - PDFThe Sciences
An Integrated Approach
- James Trefil, Robert M. Hazen(Authors)
- 2022(Publication Date)
- Wiley(Publisher)
These molecules are fundamental building blocks of every living thing, and so they are an essential part of our diets. We need a steady supply of these molecules because we are, quite literally, what we eat. Food tastes good because our taste buds are fine-tuned to these critical molecules. SCIENCE THROUGH THE DAY Jonathan A. Meyers/Science Source 602 Chapter 22 Molecules of Life 1. Most Molecules in Living Systems Are Based on the Chemistry of Carbon In Chapter 10, we saw that carbon atoms possess the unique ability to form molecules of almost any size and shape—long chains, branches, and rings. In fact, chemists usually refer to molecules containing carbon as Organic Molecules, whether or not they are part of a living system. The branch of science devoted to the study of such carbon-based mol- ecules and their reactions is called organic chemistry. 2. Life’s Molecules Form from Very Few Different Elements In terms of the percentages of atoms, just four elements—hydrogen, oxygen, carbon, and nitrogen—comprise 97.5% of our bodies’ weight. Calcium in bones accounts for 2%, whereas phosphorus, sulfur, and all the other elements make up the remaining 0.5% (see Table 22.1). These elements combine to form the molecules that control chemical reactions in all living things. 3. The Molecules of Life Are Modular, Composed of Simple Building Blocks Large and complicated molecules could be put together in two contrasting ways. One way would be to build each one from scratch, so that no piece of one molecule would be part of another. Another very different way would be to make the molecules modular, that is, to build them from a succession of simpler, widely available parts so that each large mol- ecule differs from another only in the arrangement of those parts. Nature, for the most part, displays modularity in the molecules of living systems. Modern buildings illustrate the versatility of modular construction.
eBook - PDFLife in Space
Astrobiology for Everyone
- Lucas John Mix(Author)
- 2009(Publication Date)
- Harvard University Press(Publisher)
15 Molecules How do elements come together to form the structure of life as we know it? The first step is the construction of molecules. Almost every struc-ture in your body was built out of one of only four types of biological molecules—carbohydrates, proteins, nucleic acids, and lipids. Each kind of “biomolecule” ranges in size from a few atoms joined together to huge strings that can involve thousands of atoms. In this chapter, I introduce some of the immense variety of biological molecules found in terrean life. Each section begins with a discussion of how to get from atoms to sim-ple molecules. Six elements make up 95 percent of all organic matter— carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur. Using car-bon chains as a backbone, life adds functional groups to make the molecules useful for biological work. The first three types of biomolecule, carbohydrates, proteins, and nucleic acids, each come in a number of sizes. Small units, called monomers, join together to form long chains or poly-mers. So carbohydrates are built out of sugars, proteins out of amino acids, and nucleic acids out of nucleotides. Lipids can also come in multiple unit strings, but the process is a little more complicated. After covering the atomic foundations of the biomolecules, I mention some of the most significant examples. We encounter each type of biomol- 200 LIFE IN SPACE ecule in our daily lives and can learn to recognize the important biochem-istry involved. Sugars and Carbohydrates Carbohydrates make up the first category of biomolecules. They are com-posed of one part carbon, one part oxygen, and two parts hydrogen—or something close to that ratio, hence the name “carbohydrate.” Carbohy-drates should be familiar to most readers because we use them for fuel. Animals have a metabolism that burns sugar, the building blocks of carbo-hydrates, in a process called respiration.
eBook - PDF- Rose Marie O. Mendoza(Author)
- 2019(Publication Date)
- Arcler Press(Publisher)
Fundamentals of Organic Compounds and Their Characteristics Chapter 1 CONTENTS 1.1. Introduction ........................................................................................ 2 1.2. Historical Background ........................................................................ 2 1.3. Carbon Bonding ................................................................................. 4 1.4. Organic Functional Groups ................................................................ 6 1.5. Spectroscopy of the Organic Compounds ......................................... 17 References ............................................................................................... 27 Elementary Organic Spectroscopy 2 1.1. INTRODUCTION Generally, organic compounds are the substances which contain carbon (C). The carbon atoms are responsible for the main structural framework which generates the vast range of the organic compounds. All the things on Earth (and probably elsewhere in-universe) which can be defined as living have the crucial dependence on the organic compounds. Biomolecules like proteins, carbohydrates, and fats are organic. The vital substances such as chlorophyll, hemoglobin, hormones, enzymes, and vitamins are also organic compounds. Other materials which add to the health, comfort or convenience of the humans are composed of the organic compounds, including the clothing made of silk, cotton, wool, and synthetic fibers. Fuels and its sources such as petroleum, wood, natural gas and coal; components of the protective coatings like enamels, paints, varnishes, and lacquers; antibiotics and the synthetic drugs; dyes; plastics; natural and the synthetic rubber; and pesticides are composed of the organic compounds (Fang et al., 2001).
eBook - ePub- Alexander Fridman, Gary Friedman(Authors)
- 2012(Publication Date)
- Wiley(Publisher)
In contrast to releasing energy in the form of heat, living systems often convert the energy of the redox reaction into other forms including electrostatic; this is the case in cellular respiration when electrons are transported across membranes of intracellular organelles (mitochondria). In fact, it appears that plasma treatment interacts with cells and tissues at least in part by directly or indirectly influencing redox reactions in cells and cellular respiration.3.1.2 Main classes of Organic Molecules in living systemsIn living systems there are four main classes of macromolecules that perform a variety of functions: (1) carbohydrates and sugars; (2) lipids (fats and oils); (3) polypeptides (proteins); and (4) nucleic acids.3.1.2.1 CarbohydratesCarbohydrates (synonymous with saccharides in biochemistry) consist of carbon, oxygen and hydrogen where the number of hydrogen atoms is about twice as large as the number of oxygen atoms which, in turn, is about the same as the number of carbon atoms. Carbohydrates are used for a relatively short-term and intermediate-term energy storage (starch for plants and glycogen for animals). They are also employed as structural components in some cells (cellulose in the cell walls of plants and many protists and chitin in the exoskeleton of insects and other arthropods).Sugars are structurally the simplest carbohydrates. They are the key building materials that make up other types of carbohydrates. Monosaccharides (see examples in Figure 3.3 ) are the simplest and smallest sugar molecules with a formula [CH2 O]n , where n is typically between 3 and 6. Some important monosaccharides include ribose (C5 H10 O5 ), glucose (C6 H12 O6 ), and fructose. We classify monosaccharides by the number of carbon atoms, the arrangement of atoms (molecules that have the same chemical formula but different atomic arrangements are called isomers) and the types of functional groups present in them. For example, glucose and fructose (illustrated in Figure 3.3 ) have the same chemical formula (C6 H12 O6 ), but a different structure. Glucose has an aldehyde (internal hydroxyl shown as –OH) and fructose has a keto group (internal double-bond O, shown as =O). This functional group difference, as small as it seems, accounts for the greater sweetness of fructose as compared to glucose. In an aqueous solution, glucose tends to have two isomer structures, α - and β -, with an intermediate straight-chain form (shown in Figure 3.3
At the top of the list is “Calories”—a measure of food energy. Our bodies require energy to do work, just like every other physical system. That’s why we get hungry. The nutrition facts also include information on specific kinds of molecules, notably fat, carbohydrates, and protein. These molecules are fundamental building blocks of every living thing and so are an essential part of our diets. We need a steady supply of these molecules because we are, quite literally, what we eat. Food tastes good because our taste buds are fine-tuned to these critical molecules. ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• Johnathan A. Meyers/Photo Researchers/Getty Images, Inc. 483 484 | CHAPTER 22 | Molecules of Life refer to molecules containing carbon as Organic Molecules, whether or not they are part of a living system. The branch of science devoted to the study of such carbon-based molecules and their reactions is called organic chemistry. 2. Life’s Molecules Form from Very Few Different Elements In terms of the percentages of atoms, just four elements—hydrogen, oxygen, carbon, and nitrogen—comprise 97.5% of our bodies’ weight. Calcium in bones accounts for 2%, whereas phosphorus, sulfur, and all the other elements make up the remaining 0.5% (see Table 22-1). These elements combine to form the molecules that control chemical reactions in all living things. 3. The Molecules of Life Are Modular, Composed of Simple Building Blocks Large and complicated molecules could be put together in two contrasting ways. One way would be to build each one from scratch, so that no piece of one molecule would be part of another. Another very different way would be to make the molecules modu- lar—that is, build them from a succession of simpler, widely available parts so that each large molecule differs from another only in the arrangement of those parts.
eBook - ePub- Volodymyr Ivanov(Author)
- 2020(Publication Date)
- CRC Press(Publisher)
2Biomolecules
Chemical Features of Life
The major chemical features of life are as follows:- 1. Such elements as H, C, N, O, P, and S are major elements of live matter (biomass). Carbon is the most important element. It chemically bonds to other atoms in a number of ways to produce biomolecules.
- 2. Many molecules in biomass are specific stereoisomers, that is, molecules having the same structural formulas but where one is the mirror image of the other, just as the left hand is a mirror image of the right hand.
- 3. The same types of biomolecules can be found in all forms of life, from bacteria to humans.
- 4. Biomolecules include such groups of monomers as monosaccharides, aminoacids, and nucleotides, which are used for the synthesis of polysaccharides, proteins, and nucleic acids (RNA and DNA), respectively.
- 5. All biochemical reactions are accelerated by protein catalysts called enzymes.
- 6. Nucleic acids carry genetic information and are used as tools for the biosynthesis of enzymes.
Balance of Elements
The balance of only four atoms – C, H, O, and N – can be accounted for in biotechnological calculations. For example, the most common empirical formula of biomass is CH1.7 O0.5 N0.12 . By the mass conservation law, elements do not disappear in biochemical reactions. So, all equations must be balanced by elements. For example, the aerobic biosynthesis of biomass from glucose (empirical formula C6 H12 O6 ) can be described by the balanced equation:C 6H12O 6+ 8.1O 2+ 0.36 NH 3→ 3 CH1.7O0.5N+ 3 C0.12O 2+ 4.35H 2OCovalent Bonds
The sharing of electrons between atoms constitutes a chemical bond. If electrons are shared equally, the bond is covalent, usually shown as C–C, C–N, C–O (a solid line represents a covalent bond). Covalent bonds can also be double or triple, shown as C=C, C=O or C≡C, respectively.
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