Biomolecules/Origin of Biomolecules/Carbohydrates/Proteins/Lipids/Nucleic acids/Enzymes
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A biomolecule or biological molecule
A biomolecule or biological molecule is a loosely used term for molecules and ions present in organisms that are essential to one or more typically biological processes, such as cell division, morphogenesis, or development.[1] Biomolecules include large macromolecules (or polyanions) such as proteins, carbohydrates, lipids, and nucleic acids, as well as small molecules such as primary metabolites, secondary metabolites and natural products. A more general name for this class of material is biological materials. Biomolecules are usually[citation needed] endogenous, produced within the organism[2] but organisms usually need exogenous biomolecules, for example certain nutrients, to survive.
Biology and its subfields of biochemistry and molecular biology study biomolecules and their reactions. Most biomolecules are organic compounds, and just four elements—oxygen, carbon, hydrogen, and nitrogen—make up 96% of the human body's mass. But many other elements, such as the various biometals, are present in small amounts.
The uniformity of both specific types of molecules (the biomolecules) and of certain metabolic pathways are invariant features among the wide diversity of life forms; thus these biomolecules and metabolic pathways are referred to as "biochemical universals"[3] or "theory of material unity of the living beings", a unifying concept in biology, along with cell theory and evolution theory.[4]
Contents
1 Types of biomolecules
2 Nucleosides and nucleotides
2.1 DNA and RNA structure
3 Saccharides
4 Lignin
5 Lipid
6 Amino acids
6.1 Protein structure
6.1.1 Apoenzymes
6.1.2 Isoenzymes
7 See also
8 References
9 External links
Types of biomolecules
A diverse range of biomolecules exist, including:
Small molecules:
Lipids, fatty acids, glycolipids, sterols, monosaccharides
Vitamins
Hormones, neurotransmitters
Metabolites
Monomers, oligomers and polymers:
Biomonomers Bio-oligo Biopolymers Polymerization process Covalent bond name between monomers
Amino acids Oligopeptides Polypeptides, proteins (hemoglobin...) Polycondensation Peptide bond
Monosaccharides Oligosaccharides Polysaccharides (cellulose...) Polycondensation Glycosidic bond
Isoprene Terpenes Polyterpenes: cis-1,4-polyisoprene natural rubber and trans-1,4-polyisoprene gutta-percha Polyaddition
Nucleotides Oligonucleotides Polynucleotides, nucleic acids (DNA, RNA) Phosphodiester bond
Nucleosides and nucleotides
Main articles: Nucleosides and Nucleotides
Nucleosides are molecules formed by attaching a nucleobase to a ribose or deoxyribose ring. Examples of these include cytidine (C), uridine (U), adenosine (A), guanosine (G), and thymidine (T).
Nucleosides can be phosphorylated by specific kinases in the cell, producing nucleotides. Both DNA and RNA are polymers, consisting of long, linear molecules assembled by polymerase enzymes from repeating structural units, or monomers, of mononucleotides. DNA uses the deoxynucleotides C, G, A, and T, while RNA uses the ribonucleotides (which have an extra hydroxyl(OH) group on the pentose ring) C, G, A, and U. Modified bases are fairly common (such as with methyl groups on the base ring), as found in ribosomal RNA or transfer RNAs or for discriminating the new from old strands of DNA after replication.[5]
Each nucleotide is made of an acyclic nitrogenous base, a pentose and one to three phosphate groups. They contain carbon, nitrogen, oxygen, hydrogen and phosphorus. They serve as sources of chemical energy (adenosine triphosphate and guanosine triphosphate), participate in cellular signaling (cyclic guanosine monophosphate and cyclic adenosine monophosphate), and are incorporated into important cofactors of enzymatic reactions (coenzyme A, flavin adenine dinucleotide, flavin mononucleotide, and nicotinamide adenine dinucleotide phosphate).[6]
DNA and RNA structure
Main articles: DNA and Nucleic acid structure
DNA structure is dominated by the well-known double helix formed by Watson-Crick base-pairing of C with G and A with T. This is known as B-form DNA, and is overwhelmingly the most favorable and common state of DNA; its highly specific and stable base-pairing is the basis of reliable genetic information storage. DNA can sometimes occur as single strands (often needing to be stabilized by single-strand binding proteins) or as A-form or Z-form helices, and occasionally in more complex 3D structures such as the crossover at Holliday junctions during DNA replication.[6]
Stereo 3D image of a group I intron ribozyme (PDB file 1Y0Q); gray lines show base pairs; ribbon arrows show double-helix regions, blue to red from 5' to 3' end;
Biology and its subfields of biochemistry and molecular biology study biomolecules and their reactions. Most biomolecules are organic compounds, and just four elements—oxygen, carbon, hydrogen, and nitrogen—make up 96% of the human body's mass. But many other elements, such as the various biometals, are present in small amounts.
The uniformity of both specific types of molecules (the biomolecules) and of certain metabolic pathways are invariant features among the wide diversity of life forms; thus these biomolecules and metabolic pathways are referred to as "biochemical universals"[3] or "theory of material unity of the living beings", a unifying concept in biology, along with cell theory and evolution theory.[4]
Contents
1 Types of biomolecules
2 Nucleosides and nucleotides
2.1 DNA and RNA structure
3 Saccharides
4 Lignin
5 Lipid
6 Amino acids
6.1 Protein structure
6.1.1 Apoenzymes
6.1.2 Isoenzymes
7 See also
8 References
9 External links
Types of biomolecules
A diverse range of biomolecules exist, including:
Small molecules:
Lipids, fatty acids, glycolipids, sterols, monosaccharides
Vitamins
Hormones, neurotransmitters
Metabolites
Monomers, oligomers and polymers:
Biomonomers Bio-oligo Biopolymers Polymerization process Covalent bond name between monomers
Amino acids Oligopeptides Polypeptides, proteins (hemoglobin...) Polycondensation Peptide bond
Monosaccharides Oligosaccharides Polysaccharides (cellulose...) Polycondensation Glycosidic bond
Isoprene Terpenes Polyterpenes: cis-1,4-polyisoprene natural rubber and trans-1,4-polyisoprene gutta-percha Polyaddition
Nucleotides Oligonucleotides Polynucleotides, nucleic acids (DNA, RNA) Phosphodiester bond
Nucleosides and nucleotides
Main articles: Nucleosides and Nucleotides
Nucleosides are molecules formed by attaching a nucleobase to a ribose or deoxyribose ring. Examples of these include cytidine (C), uridine (U), adenosine (A), guanosine (G), and thymidine (T).
Nucleosides can be phosphorylated by specific kinases in the cell, producing nucleotides. Both DNA and RNA are polymers, consisting of long, linear molecules assembled by polymerase enzymes from repeating structural units, or monomers, of mononucleotides. DNA uses the deoxynucleotides C, G, A, and T, while RNA uses the ribonucleotides (which have an extra hydroxyl(OH) group on the pentose ring) C, G, A, and U. Modified bases are fairly common (such as with methyl groups on the base ring), as found in ribosomal RNA or transfer RNAs or for discriminating the new from old strands of DNA after replication.[5]
Each nucleotide is made of an acyclic nitrogenous base, a pentose and one to three phosphate groups. They contain carbon, nitrogen, oxygen, hydrogen and phosphorus. They serve as sources of chemical energy (adenosine triphosphate and guanosine triphosphate), participate in cellular signaling (cyclic guanosine monophosphate and cyclic adenosine monophosphate), and are incorporated into important cofactors of enzymatic reactions (coenzyme A, flavin adenine dinucleotide, flavin mononucleotide, and nicotinamide adenine dinucleotide phosphate).[6]
DNA and RNA structure
Main articles: DNA and Nucleic acid structure
DNA structure is dominated by the well-known double helix formed by Watson-Crick base-pairing of C with G and A with T. This is known as B-form DNA, and is overwhelmingly the most favorable and common state of DNA; its highly specific and stable base-pairing is the basis of reliable genetic information storage. DNA can sometimes occur as single strands (often needing to be stabilized by single-strand binding proteins) or as A-form or Z-form helices, and occasionally in more complex 3D structures such as the crossover at Holliday junctions during DNA replication.[6]
Stereo 3D image of a group I intron ribozyme (PDB file 1Y0Q); gray lines show base pairs; ribbon arrows show double-helix regions, blue to red from 5' to 3' end;
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