1.
Electron
–
The electron is a subatomic particle, symbol e− or β−, with a negative elementary electric charge. Electrons belong to the first generation of the lepton particle family, the electron has a mass that is approximately 1/1836 that of the proton. Quantum mechanical properties of the include a intrinsic angular momentum of a half-integer value, expressed in units of the reduced Planck constant. As it is a fermion, no two electrons can occupy the same state, in accordance with the Pauli exclusion principle. Like all elementary particles, electrons exhibit properties of particles and waves, they can collide with other particles and can be diffracted like light. Since an electron has charge, it has an electric field. Electromagnetic fields produced from other sources will affect the motion of an electron according to the Lorentz force law, electrons radiate or absorb energy in the form of photons when they are accelerated. Laboratory instruments are capable of trapping individual electrons as well as electron plasma by the use of electromagnetic fields, special telescopes can detect electron plasma in outer space. Electrons are involved in applications such as electronics, welding, cathode ray tubes, electron microscopes, radiation therapy, lasers, gaseous ionization detectors. Interactions involving electrons with other particles are of interest in fields such as chemistry. The Coulomb force interaction between the positive protons within atomic nuclei and the negative electrons without, allows the composition of the two known as atoms, ionization or differences in the proportions of negative electrons versus positive nuclei changes the binding energy of an atomic system. The exchange or sharing of the electrons between two or more atoms is the cause of chemical bonding. In 1838, British natural philosopher Richard Laming first hypothesized the concept of a quantity of electric charge to explain the chemical properties of atoms. Irish physicist George Johnstone Stoney named this charge electron in 1891, electrons can also participate in nuclear reactions, such as nucleosynthesis in stars, where they are known as beta particles. Electrons can be created through beta decay of isotopes and in high-energy collisions. The antiparticle of the electron is called the positron, it is identical to the electron except that it carries electrical, when an electron collides with a positron, both particles can be totally annihilated, producing gamma ray photons. The ancient Greeks noticed that amber attracted small objects when rubbed with fur, along with lightning, this phenomenon is one of humanitys earliest recorded experiences with electricity. In his 1600 treatise De Magnete, the English scientist William Gilbert coined the New Latin term electricus, both electric and electricity are derived from the Latin ēlectrum, which came from the Greek word for amber, ἤλεκτρον
2.
Protein
–
Proteins are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, a linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide, short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides, or sometimes oligopeptides. The individual amino acid residues are bonded together by peptide bonds, the sequence of amino acid residues in a protein is defined by the sequence of a gene, which is encoded in the genetic code. In general, the code specifies 20 standard amino acids, however. Sometimes proteins have non-peptide groups attached, which can be called prosthetic groups or cofactors, proteins can also work together to achieve a particular function, and they often associate to form stable protein complexes. Once formed, proteins only exist for a period of time and are then degraded and recycled by the cells machinery through the process of protein turnover. A proteins lifespan is measured in terms of its half-life and covers a wide range and they can exist for minutes or years with an average lifespan of 1–2 days in mammalian cells. Abnormal and or misfolded proteins are degraded more rapidly due to being targeted for destruction or due to being unstable. Like other biological macromolecules such as polysaccharides and nucleic acids, proteins are essential parts of organisms, many proteins are enzymes that catalyse biochemical reactions and are vital to metabolism. Proteins also have structural or mechanical functions, such as actin and myosin in muscle and the proteins in the cytoskeleton, other proteins are important in cell signaling, immune responses, cell adhesion, and the cell cycle. In animals, proteins are needed in the diet to provide the essential amino acids that cannot be synthesized, digestion breaks the proteins down for use in the metabolism. Methods commonly used to study structure and function include immunohistochemistry, site-directed mutagenesis, X-ray crystallography, nuclear magnetic resonance. Most proteins consist of linear polymers built from series of up to 20 different L-α-amino acids, all proteinogenic amino acids possess common structural features, including an α-carbon to which an amino group, a carboxyl group, and a variable side chain are bonded. Only proline differs from this structure as it contains an unusual ring to the N-end amine group. The amino acids in a chain are linked by peptide bonds. Once linked in the chain, an individual amino acid is called a residue, and the linked series of carbon, nitrogen. The peptide bond has two forms that contribute some double-bond character and inhibit rotation around its axis, so that the alpha carbons are roughly coplanar
3.
Jmol
–
Jmol is computer software for molecular modelling chemical structures in 3-dimensions. Jmol returns a 3D representation of a molecule that may be used as a teaching tool and it is written in the programming language Java, so it can run on the operating systems Windows, macOS, Linux, and Unix, if Java is installed. It is free and open-source software released under a GNU Lesser General Public License version 2.0, a standalone application and a software development kit exist that can be integrated into other Java applications, such as Bioclipse and Taverna. A popular feature is an applet that can be integrated into web pages to display molecules in a variety of ways, for example, molecules can be displayed as ball-and-stick models, space-filling models, ribbon diagrams, etc. Jmol supports a range of chemical file formats, including Protein Data Bank, Crystallographic Information File, MDL Molfile. There is also a JavaScript-only version, JSmol, that can be used on computers with no Java, the Jmol applet, among other abilities, offers an alternative to the Chime plug-in, which is no longer under active development. While Jmol has many features that Chime lacks, it does not claim to reproduce all Chime functions, most notably, Chime requires plug-in installation and Internet Explorer 6.0 or Firefox 2.0 on Microsoft Windows, or Netscape Communicator 4.8 on Mac OS9. Jmol requires Java installation and operates on a variety of platforms. For example, Jmol is fully functional in Mozilla Firefox, Internet Explorer, Opera, Google Chrome, fast and Scriptable Molecular Graphics in Web Browsers without Java3D
4.
Organic chemistry
–
Study of structure includes many physical and chemical methods to determine the chemical composition and the chemical constitution of organic compounds and materials. In the modern era, the range extends further into the table, with main group elements, including, Group 1 and 2 organometallic compounds. They either form the basis of, or are important constituents of, many products including pharmaceuticals, petrochemicals and products made from them, plastics, fuels and explosives. Before the nineteenth century, chemists generally believed that compounds obtained from living organisms were endowed with a force that distinguished them from inorganic compounds. According to the concept of vitalism, organic matter was endowed with a vital force, during the first half of the nineteenth century, some of the first systematic studies of organic compounds were reported. Around 1816 Michel Chevreul started a study of soaps made from various fats and he separated the different acids that, in combination with the alkali, produced the soap. Since these were all compounds, he demonstrated that it was possible to make a chemical change in various fats, producing new compounds. In 1828 Friedrich Wöhler produced the chemical urea, a constituent of urine, from inorganic starting materials. The event is now accepted as indeed disproving the doctrine of vitalism. In 1856 William Henry Perkin, while trying to manufacture quinine accidentally produced the organic dye now known as Perkins mauve and his discovery, made widely known through its financial success, greatly increased interest in organic chemistry. A crucial breakthrough for organic chemistry was the concept of chemical structure, ehrlich popularized the concepts of magic bullet drugs and of systematically improving drug therapies. His laboratory made decisive contributions to developing antiserum for diphtheria and standardizing therapeutic serums, early examples of organic reactions and applications were often found because of a combination of luck and preparation for unexpected observations. The latter half of the 19th century however witnessed systematic studies of organic compounds, the development of synthetic indigo is illustrative. The production of indigo from plant sources dropped from 19,000 tons in 1897 to 1,000 tons by 1914 thanks to the methods developed by Adolf von Baeyer. In 2002,17,000 tons of indigo were produced from petrochemicals. In the early part of the 20th Century, polymers and enzymes were shown to be large organic molecules, the multiple-step synthesis of complex organic compounds is called total synthesis. Total synthesis of natural compounds increased in complexity to glucose. For example, cholesterol-related compounds have opened ways to synthesize complex human hormones, since the start of the 20th century, complexity of total syntheses has been increased to include molecules of high complexity such as lysergic acid and vitamin B12
5.
Acetylcholine
–
Its name is derived from its chemical structure, it is an ester of acetic acid and choline. Parts in the body that use or are affected by acetylcholine are referred to as cholinergic, substances that interfere with acetylcholine activity are called anticholinergics. Acetylcholine is the used at the neuromuscular junction—in other words. This property means that drugs that affect cholinergic systems can have dangerous effects ranging from paralysis to convulsions. In the brain, acetylcholine functions as a neurotransmitter and as a neuromodulator, the brain contains a number of cholinergic areas, each with distinct functions. They play an important role in arousal, attention, memory, scopolamine, which acts mainly on muscarinic receptors in the brain, can cause delirium and amnesia. The addictive qualities of nicotine derive from its effects on nicotinic receptors in the brain. Acetylcholine has functions both in the nervous system and in the central nervous system. In the peripheral nervous system, acetylcholine activates muscles, and is a major neurotransmitter in the nervous system. In the CNS, cholinergic projections from the basal forebrain to the cerebral cortex, like many other biologically active substances, acetylcholine exerts its effects by binding to and activating receptors located on the surface of cells. There are two classes of acetylcholine receptor, nicotinic and muscarinic. Nicotinic acetylcholine receptors are ligand-gated ion channels permeable to sodium, potassium, in other words, they are ion channels embedded in cell membranes, capable of switching from a closed to open state when acetylcholine binds to them, in the open state they allow ions to pass through. Nicotinic receptors come in two types, known as muscle-type and neuronal-type. The muscle-type can be blocked by curare, the neuronal-type by hexamethonium. The main location of muscle-type receptors is on muscle cells, as described in detail below. Neuronal-type receptors are located in autonomic ganglia, and in the nervous system. Muscarinic acetylcholine receptors have a complex mechanism, and affect target cells over a longer time frame. In mammals, five subtypes of muscarinic receptors have been identified, labeled M1 through M5, all of them function as G protein-coupled receptors, meaning that they exert their effects via a second messenger system
6.
Transcription (biology)
–
Transcription is the first step of gene expression, in which a particular segment of DNA is copied into RNA by the enzyme RNA polymerase. Both DNA and RNA are nucleic acids, which use base pairs of nucleotides as a complementary language, during transcription, a DNA sequence is read by an RNA polymerase, which produces a complementary, antiparallel RNA strand called a primary transcript. Transcription proceeds in the general steps, RNA polymerase, together with one or more general transcription factors. RNA polymerase creates a bubble, which separates the two strands of the DNA helix. This is done by breaking the bonds between complementary DNA nucleotides. RNA sugar-phosphate backbone forms with assistance from RNA polymerase to form an RNA strand, hydrogen bonds of the RNA–DNA helix break, freeing the newly synthesized RNA strand. If the cell has a nucleus, the RNA may be further processed and this may include polyadenylation, capping, and splicing. The RNA may remain in the nucleus or exit to the cytoplasm through the pore complex. The stretch of DNA transcribed into an RNA molecule is called a transcription unit, if the gene encodes a protein, the transcription produces messenger RNA, the mRNA, in turn, serves as a template for the proteins synthesis through translation. Alternatively, the gene may encode for either non-coding RNA, ribosomal RNA, transfer RNA. Overall, RNA helps synthesize, regulate, and process proteins, in virology, the term may also be used when referring to mRNA synthesis from an RNA molecule. For instance, the genome of a negative-sense single-stranded RNA virus may be template for a positive-sense single-stranded RNA and this is because the positive-sense strand contains the information needed to translate the viral proteins for viral replication afterwards. This process is catalyzed by a viral RNA replicase, the regulatory sequence before the coding sequence is called the five prime untranslated region, the sequence after the coding sequence is called the three prime untranslated region. As opposed to DNA replication, transcription results in an RNA complement that includes the nucleotide uracil in all instances where thymine would have occurred in a DNA complement, only one of the two DNA strands serve as a template for transcription. The antisense strand of DNA is read by RNA polymerase from the 3 end to the 5 end during transcription. The complementary RNA is created in the direction, in the 5 →3 direction. This directionality is because RNA polymerase can only add nucleotides to the 3 end of the growing mRNA chain and this use of only the 3 →5 DNA strand eliminates the need for the Okazaki fragments that are seen in DNA replication. This also removes the need for an RNA primer to initiate RNA synthesis, the non-template strand of DNA is called the coding strand, because its sequence is the same as the newly created RNA transcript
7.
Acetylation
–
Acetylation describes a reaction that introduces an acetyl functional group into a chemical compound. Deacetylation is the removal of an acetyl group, Acetylation refers to the process of introducing an acetyl group into a compound, namely the substitution of an acetyl group for an active hydrogen atom. A reaction involving the replacement of the atom of a hydroxyl group with an acetyl group yields a specific ester. Acetic anhydride is used as an acetylating agent reacting with free hydroxyl groups. For example, it is used in the synthesis of aspirin and heroin, Acetylation is an important modification of proteins in cell biology, and proteomics studies have identified thousands of acetylated mammalian proteins. Acetylation occurs as a co-translational and post-translational modification of proteins, for example, histones, p53, among these proteins, chromatin proteins and metabolic enzymes are highly represented, indicating that acetylation has a considerable impact on gene expression and metabolism. In bacteria, 90% of proteins involved in metabolism of Salmonella enteric are acetylated. N-terminal acetylation is one of the most common co-translational covalent modifications of proteins in eukaryotes, N-terminal acetylation plays an important role in the synthesis, stability and localization of proteins. About 85% of all proteins and 68% in yeast are acetylated at their Nα-terminus. Several proteins from prokaryotes and archaea are also modified by N-terminal acetylation, N-terminal Acetylation is catalyzed by a set of enzyme complexes, the N-terminal acetyltransferases. NATs transfer a group from acetyl-coenzyme A to the α-amino group of the first amino acid residue of the protein. Different NATs are responsible for the acetylation of nascent protein N-termini, to date, six different NATs have been found in humans - NatA, NatB, NatC, NatD, NatE and NatF. Each of these different enzyme complexes is specific for different amino acids or amino acid sequences which is shown in the following table, the Composition and Substrate specificity of NATs. NatA is composed of two subunits, the catalytic subunit Naa10 and the auxiliary subunit Naa15, NatA subunits are more complex in higher eukaryotes than in lower eukaryotes. In addition to the genes NAA10 and NAA15, the mammal-specific genes NAA11 and NAA16, make functional gene products, four possible hNatA catalytic-auxiliary dimers are formed by these four proteins. However, Naa10/Naa15 is the most abundant NatA, NatA acetylates Ser, Ala-, Gly-, Thr-, Val- and Cys N-termini after the initiator methionine is removed by methionine amino-peptidases. These amino acids are frequently expressed in the N-terminal of proteins in eukaryotes. Several different interaction partners are involved in the N-terminal acetylation by NatA, Huntingtin interacting protein K interacts with hNatA on the ribosome to affect the N-terminal acetylation of a subset of NatA substrates
verify (what is 
?)