Draft:Original research/Chemistry

This is a collection of coloured chemicals. Credit: Puppy8800.{{free media}}

Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds.

Most of Wikiversity's content on chemistry can currently be found at the School:Chemistry page.

Sciences

As an introduction to science, the Scale of the Universe is mapped to the Branches of Science. Credit: Eric Fisk.{{free media}}

Def. a natural science "that deals with the composition and constitution of substances and the changes that they undergo as a consequence of alterations in the constitution of their molecules" is called chemistry.

Def. a science that deals with

1. the identification of the substances of which matter is composed,
2. the investigation of their properties and the ways in which they interact, combine, and change, and
3. the use of these processes to form new substances

is called chemistry.

Def. "a science that deals with the composition, structure, and properties of substances and of the transformations that they undergo" is called chemistry.

Agrochemistry

A large, modern fertilizer spreader is a major part of agricultural phosphate biochemistry. Credit: Rasbak.

Agricultural chemistry is the study of both chemistry and biochemistry which are important in agricultural production, the processing of raw products into foods and beverages, and in environmental monitoring and remediation. These studies emphasize the relationships between plants, animals and bacteria and their environment.

Agricultural chemistry often aims at preserving or increasing the fertility of soil, maintaining or improving the agricultural yield, and improving the quality of the crop.

Analytical chemistry

Chemicals in labeled flasks include Ammonium Hydroxide (Aqueous ammonia) and Nitric acid lit in different colours. Credit: Joe Sullivan.{{free media}}

Analytical chemistry is the analysis of material samples to gain an understanding of their chemical composition and structure. Analytical chemistry incorporates standardized experimental methods in chemistry. These methods may be used in all subdisciplines of chemistry, excluding purely theoretical chemistry.

Astrochemistry

Astrochemistry is the study of the chemical composition of stars and outer space.

Biochemistry

File:False color synchrotron X-ray image.png

A false color synchrotron X-ray image shows the fossil chemistry. Credit: Wogelius et al..{{fairuse}}

Biochemistry is the study of the chemicals, chemical reactions and chemical interactions that take place in living organisms. Biochemistry and organic chemistry are closely related, as in medicinal chemistry or neurochemistry. Biochemistry is also associated with molecular biology and genetics.

"The range of colors in animal fur comes from varying amounts of two types of a pigment called melanin. Eumelanin produces black or dark brown coloring, while pheomelanin creates reddish or yellow hues. Pheomelanin doesn’t tend to hold up well over the millions of years most fossils are buried; eumelanin is more sturdy, which is why we have a decent idea about the patterns of light and dark in the feathers of Archaeopteryx and some of the other ancestors of today’s birds."

In the image on the right, a "false color synchrotron X-ray image [shows] the fossil chemistry. Blue represents calcium in the bones, green is the element zinc, which has been shown to be important in the biochemistry of red pigment, and red is a particular type of organic sulfur that cannot be imaged by traditional methods. This type of sulfur is enriched in red pigment. When combined, regions rich in both zinc and sulfur appear yellow on this image, showing that the fur on this animal was rich in the chemical compounds that are most probably derived from the original red pigments produced by the mouse."

Chemical "compounds with rings containing sulfur are a dead giveaway for the presence of reddish pheomelanin in recently dead animal fur or feathers. But when the animal decays, those sulfur-ring molecules break down."

"We discovered an important relationship between zinc and sulfur that we believe could be used as a ‘tag’ for resolving pheomelanin in fossils." "When pheomelanin breaks down, tiny traces of the metal remain embedded in the fossilized fibers of hair, and Wogelius and his colleagues found a way to look for those traces in order to reconstruct the coloring of the long-dead fossil field mouse."

"We thought that the preservation in this case was good enough to allow comparison with modern tissue, but old enough that it would be a good test of our new protocols for analyzing fossils."

"Using a technique called synchrotron x-ray fluorescence imaging, the team bombarded the fossil with X-rays and watched how they interacted with the metals in the fossilized strands of mouse fur. The patterns of metal traces matched the ones they had previously seen in animals with very high concentrations of the reddish pigment—everywhere except on its white underbelly."

"This study presents evidence that, beyond what we can see with the visible part of the electromagnetic spectrum, that original biological chemistry is also retained within these structures." "It also shows that paleontologists may miss important information if they only check a couple of spots for the presence of pigment. Instead, mapping how pigments vary (and often mix) across an organism’s body is the key to really understanding its coloration."

"Of course, that depends on having fossilized fur or feathers to analyze in the first place. When it died 3 million years ago, the field mouse happened to fall into a small, deep basin where sediment piled up quickly, burying the mouse and sealing it away from oxygen. That kind of good luck doesn’t happen every day."

"Common? No. But there will be hundreds of specimens either stored in museums or yet to be sampled which will have suitable material for study."

"We are busy with a number of new projects, some related to pigments and some related to other aspects of soft tissue preservation stretching back further than 3 million years."

"It has taken us over a decade to really understand the information that our primary technique (synchrotron X-ray fluorescence imaging) can provide."

"[O]rganosulfur-Zn complexes are indicators of pheomelanin (red pigment) in extant and fossil soft tissue and that the mapping of these residual biochemical compounds can be used to restore melanin pigment distribution in a 3 million year old extinct mammal species (Apodemus atavus). Synchotron Rapid Scanning X-ray Fluorescence imaging showed that the distributions of Zn and organic S are correlated within this fossil fur just as in pheomelanin-rich modern integument. Furthermore, Zn coordination chemistry within this fossil fur is closely comparable to that determined from pheomelanin-rich fur and hair standards."

Combinatorial chemistry

Combinatorial chemistry involves the rapid synthesis or the computer simulation of a large number of different but structurally related molecules.

Inorganic chemistry

Inorganic chemistry is the study of the properties and reactions of inorganic compounds. The distinction between organic and inorganic disciplines is not absolute and there is much overlap, most importantly in the sub-discipline of organometallic chemistry.

Materials chemistry

File:Electric circuit passivation layers.png

The image shows the electric circuit of the passivation layers. Credit: P. Neuderth, P. Hille, J. Schörmann, A. Frank, C. Reitz, S. Martí-Sánchez, M. de la Mata, M. Coll, J. Arbiol, R. Marschall and M. Eickhoff.{{fairuse}}

The "influence of ultra-thin TiO₂, CeO₂ and Al₂O₃ coatings deposited by atomic layer deposition on the photoelectrochemical performance of In_xGa_1−xN/GaN nanowire (NW) [photoelectrodes:] The passivation of surface states results in an increase of the anodic photocurrent (PC) by a factor of 2.5 for the deposition of 5 nm TiO₂. In contrast, the PC is reduced for CeO₂- and Al₂O₃-coated NWs due to enhanced defect recombination in the passivation layer or increased band discontinuities. Furthermore, photoelectrochemical oxidation of the In_xGa_1−xN/GaN NW photoelectrode is attenuated by the TiO₂ layer and completely suppressed for a layer thickness of 7 nm or more. Due to efficient charge transfer from the In_xGa_1−xN NW core a stable TiO₂-covered photoanode with visible light excitation is realized."

Neurochemistry

Neurochemistry is the study of neurochemicals; including transmitters, peptides, proteins, lipids, sugars, and nucleic acids; their interactions, and the roles they play in forming, maintaining, and modifying the nervous system.

Nuclear chemistry

Nuclear chemistry is the study of how subatomic particles come together and make nuclei. Modern Transmutation is a large component of nuclear chemistry, and the table of nuclides is an important result and tool for this field.

Organic chemistry

Organic chemistry is the study of the structure, properties, composition, mechanisms, and reactions of organic compounds. An organic compound is defined as any compound based on a carbon skeleton.

Physical chemistry

Physical chemistry is the study of the physical and fundamental basis of chemical systems and processes. In particular, the energetics and dynamics of such systems and processes are of interest to physical chemists. Important areas of study include chemical thermodynamics, chemical kinetics, electrochemistry, statistical mechanics, spectroscopy, and more recently, astrochemistry. Physical chemistry has large overlap with molecular physics. Physical chemistry involves the use of infinitesimal calculus in deriving equations. It is usually associated with quantum chemistry and theoretical chemistry. Physical chemistry is a distinct discipline from chemical physics, but again, there is very strong overlap.

Quantum chemistry

Quantum chemistry is the area of chemistry concerned with quantum computations of molecular properties and chemical reactions, including also theories and mechanisms of chemical reactions and processes.

Theoretical chemistry

Theoretical chemistry is the study of chemistry via fundamental theoretical reasoning (usually within mathematics or physics). In particular the application of quantum mechanics to chemistry is called quantum chemistry. Since the end of the Second World War, the development of computers has allowed a systematic development of computational chemistry, which is the art of developing and applying computer programs for solving chemical problems. Theoretical chemistry has large overlap with (theoretical and experimental) condensed matter physics and molecular physics.

Thermochemistry

Thermochemistry is the study of energy and temperature changes in a chemical process, and is closely related to thermodynamics.

Projects, courses, lessons, lectures

• Organometallic chemistry
• First Year General College Chemistry

See also

• Agriculture (Middle Bronze Age) (15 kB) (13 September 2019)
• Aquaculture
• Biochemistry
• Biomolecules
• Blood
• Botany (82 kB) (24 February 2019)
• Chemical bond properties, Wikipedia category
• Chemistry glossary
• Forestry
• Fundamentals of chemistry
• High School Chemistry
• Human DNA (Paleogene) (168 kB)
• Human teeth (30 kB) (2 July 2019)
• Ice cores (Calabrian) (100 kB)
• Introduction to polymer chemistry
• Mammalogy (Oligocene) (26 kB) (10 September 2019)
• Medical biochemistry
• Radiation astrochemistry
• School:Chemistry
• Sciences (-55th Century) (101 kB)
• What is organic chemistry?

External links

• PubChem Public Chemical Database

{{Phosphate biochemistry}}