Biochemistry, also called physiological chemistry, is the study of chemical processes in living organisms, and covers the overlap between Chemistry, Biology and Physiology. Biochemistry governs all living organisms and living processes. By controlling information flow through biochemical signaling and the flow of chemical energy through metabolism, biochemical processes give rise to the incredible complexity of life. Much of biochemistry deals with the structures and functions of cellular components such as proteins, carbohydrates, lipids, nucleic acids and other biomolecules although increasingly processes rather than individual molecules are the main focus. Over the last 40 years biochemistry has become so successful at explaining living processes that now almost all areas of the life sciences from botany to medicine are engaged in biochemical research. Today the main focus of pure biochemistry is in understanding how biological molecules give rise to the processes that occur within living cells which in turn relates greatly to the study and understanding of whole organisms.
Among the vast number of different biomolecules, many are complex and large molecules (called biopolymers), which are composed of similar repeating subunits (monomers). Each class of polymeric biomolecule has a different set of subunit types, for example, a protein is a polymer whose subunits are selected from a set of 20 or more amino acids. Biochemistry studies the chemical properties of important biological molecules, like proteins, and in particular the chemistry of enzyme-catalyzed reactions.
The biochemistry of cell metabolism and the endocrine system has been extensively described. Other areas of biochemistry include the genetic code (DNA, RNA), protein synthesis, cell membrane transport, and signal transduction.
Chemistry is the science of matter and the changes it undergoes. The science of matter is also addressed by physics, but while physics takes a more general and fundamental approach, chemistry is more specialized, being concerned with the composition, behavior (or reaction), structure, and properties of matter, as well as the changes it is subject to during chemical reactions. It is a physical science which studies various substances, atoms, molecules, crystals and other aggregates of matter whether in isolation or combination, and which incorporates the concepts of energy and entropy in relation to the spontaneity of chemical processes.
Disciplines within chemistry are traditionally grouped by the type of matter being studied or the kind of study. These include inorganic chemistry, the study of inorganic matter; organic chemistry, the study of organic (carbon based) matter; biochemistry, the study of substances found in biological organisms; physical chemistry, the study of chemical processes using physical concepts such as thermodynamics and quantum mechanics; and analytical chemistry, the analysis of material samples to gain an understanding of their chemical composition and structure. Many more specialized disciplines have emerged in recent years, e.g. neurochemistry the chemical study of the nervous system.
Electronics is the branch of science and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits. The nonlinear behaviour of these components and their ability to control electron flows makes amplification of weak signals possible, and is usually applied to information and signal processing. Electronics is distinct from electrical and electro-mechanical science and technology, which deals with the generation, distribution, switching, storage and conversion of electrical energy to and from other energy forms using wires, motors, generators, batteries, switches, relays, transformers, resistors and other passive components. This distinction started around 1906 with the invention by Lee De Forest of the triode, which made electrical amplification of weak radio signals and audio signals possible with a non-mechanical device. Until 1950 this field was called “radio technology” because its principal application was the design and theory of radio transmitters, receivers and vacuum tubes.
Today, most electronic devices use semiconductor components to perform electron control. The study of semiconductor devices and related technology is considered a branch of solid state physics, whereas the design and construction of electronic circuits to solve practical problems come under electronics engineering.
Genetics (from Ancient Greek γενετικός genetikos), is a discipline of biolog that is the science of genes, heredity, and variation in living organisms.
Genetics deals with the molecular structure and function of genes, with gene behavior in the context of a cell or organism (e.g. dominance and epigenetics), with patterns of inheritance from parent to offspring, and with gene distribution, variation and change in populations. Given that genes are universal to living organisms, genetics can be applied to the study of all living systems, from viruses and bacteria, through plants (especially crops) and domestic animals, to humans (as in medical genetics).
The fact that living things inherit traits from their parents has been used since prehistoric times to improve crop plants and animals through selective breeding. However, the modern science of genetics, which seeks to understand the process of inheritance, only began with the work of Gregor Mendel in the mid-19th century. Although he did not know the physical basis for heredity, Mendel observed that organisms inherit traits via discrete units of inheritance, which are now called genes.
Genes correspond to regions within DNA, a molecule composed of a chain of four different types of nucleotides—the sequence of these nucleotides is the genetic information organisms inherit. DNA naturally occurs in a double stranded form, with nucleotides on each strand complementary to each other. Each strand can act as a template for creating a new partner strand. This is the physical method for making copies of genes that can be inherited.
The sequence of nucleotides in a gene is translated by cells to produce a chain of amino acids, creating proteins—the order of amino acids in a protein corresponds to the order of nucleotides in the gene. This relationship between nucleotide sequence and amino acid sequence is known as the genetic code. The amino acids in a protein determine how it folds into a three-dimensional shape; this structure is, in turn, responsible for the protein’s function. Proteins carry out almost all the functions needed for cells to live. A change to the DNA in a gene can change a protein’s amino acids, changing its shape and function: this can have a dramatic effect in the cell and on the organism as a whole.
Although genetics plays a large role in the appearance and behavior of organisms, it is the combination of genetics with what an organism experiences that determines the ultimate outcome. For example, while genes play a role in determining an organism’s size, the nutrition and health it experiences after inception also have a large effect.
The classical selective breeding methods, which are often imprecise and lengthy, are nowadays being replaced by modern genome editing methods. The best-known example is the CRISPR/Cas method (Clustered Regularly Interspaced Short Palindromic Repeats -CRISPR-associated), a molecular biological method for cutting and modifying DNA in a targeted manner. Genes can be inserted, removed or switched off with the CRISPR/Cas system, and nucleotides in a gene can also be changed. Due to its ease of implementation, scalability in terms of different target sequences, and low cost, the CRISPR/Cas method is increasingly used in research. The development of the CRISPR/Cas method was awarded the Nobel Prize in Chemistry in 2020.
Mechanical engineering is a discipline of engineering that applies the principles of physics and materials science for analysis, design, manufacturing, and maintenance of mechanical systems. It is the branch of engineering that involves the production and usage of heat and mechanical power for the design, production, and operation of machines and tools. It is one of the oldest and broadest engineering disciplines.
The engineering field requires an understanding of core concepts including mechanics, kinematics, thermodynamics, materials science, and structural analysis. Mechanical engineers use these core principles along with tools like computer-aided engineering and product lifecycle management to design and analyze manufacturing plants, industrial equipment and machinery, heating and cooling systems, transport systems, aircraft, watercraft, robotics, medical devices and more.
Mechanical engineering emerged as a field during the industrial revolution in Europe in the 18th century; however, its development can be traced back several thousand years around the world. Mechanical engineering science emerged in the 19th century as a result of developments in the field of physics. The field has continually evolved to incorporate advancements in technology, and mechanical engineers today are pursuing developments in such fields as composites, mechatronics, and nanotechnology. Mechanical engineering overlaps with aerospace engineering, civil engineering, electrical engineering, petroleum engineering, and chemical engineering to varying amounts.
Mobile devices such as cell phones, tablet computers, laptops and the like have an enormous impact on our daily lives. Cell phones, for example, now provide numerous software applications (apps) in addition to classic telephony that enrich our everyday lives in terms of Internet access, navigation, communication, control of devices, security and social media. Life in Western society is hardly imaginable without mobile devices.
Many apps require Internet access. This is achieved by receiving radio signals through any number of cellular base stations equipped with microwave antennas. These sites are typically mounted on a tower, pole, or building located in populated areas and then connected to a wired communications network and switching system. Cellular phones, as an example, have a low-power transceiver that transmits voice and data to the nearest cellular sites, which are typically no more than 8 to 13 km (about 5 to 8 miles) away. In areas of low coverage, a cellular repeater can be used, which uses a high-sensitivity dish antenna or Yagi antenna to communicate over long distances with a cell tower far beyond normal range and uses a repeater to retransmit to a small local antenna with a short range that allows any cell phone within a few meters to function properly.
When the cellular phone or mobile device is turned on, it registers with the cellular exchange using its unique identifier and can then be notified by the exchange when a phone call is received or a network connection is to be established. The mobile device constantly searches for the strongest signal received from surrounding base stations and can seamlessly switch between locations. As the user moves around the network, “handoffs” are performed to allow the device to change locations without breaking the connection.
Cell sites have relatively low-power radio transmitters (often as little as one or two watts) that broadcast their presence and relay communications between mobile terminals and the switching center. The exchange, in turn, connects, for example, a call to another subscriber of the same mobile operator or to the public telephone network, which includes the networks of other mobile operators. Many of these sites are camouflaged to blend into the existing environment, especially in scenic areas.
The dialog between the cellular phone and the cell site is a digital data stream that also includes digitized audio data (except for first-generation analog networks). The technology used to achieve this depends on the system that the mobile operator has implemented. Technologies are classified by generation. The first generation systems, introduced in Japan in 1979, are all analog and include AMPS and NMT. Second-generation systems, introduced in Finland in 1991, are all digital and include GSM, CDMA and TDMA. Modern wireless standards include third (3G), fourth (4G or LTE), and fifth (5G) generation.
Some older wireless technologies make phones susceptible to “cloning.” Whenever a cell phone goes out of range (e.g., in a road tunnel), once the signal is restored, it sends a “reconnect” signal to the nearest cell tower to identify itself and signal that it is ready to transmit again. With the right equipment, it is possible to intercept the reconnect signal and encode the data it contains into a “blank” phone – for all intents and purposes: the “blank” phone is then an exact duplicate of the real phone, and all calls made with the “clone” are billed to the original account. This problem was widespread with the first generation of analog technology, but later digital standards from GSM onwards significantly improve security and make cloning more difficult.
In an effort to limit the potential harm from having a transmitter close to the user’s body, the first fixed/mobile cellular phones that had a separate transmitter, vehicle-mounted antenna, and handset (known as car phones and bag phones) were limited to a maximum 3 watts Effective Radiated Power. Modern handheld cellphones which must have the transmission antenna held inches from the user’s skull are limited to a maximum transmission power of 0.6 watts ERP.
Molecular biology is the branch of biology that deals with the molecular basis of biological activity. This field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry. Molecular biology chiefly concerns itself with understanding and the interactions between the various systems of a cell, including the interactions between the different types of DNA, RNA and protein biosynthesis as well as learning how these interactions are regulated. Writing in “Nature” in 1961, William Astbury described molecular biology as not so much a technique as an approach from the viewpoint of the so-called basic sciences with the leading idea of searching below the large-scale manifestations of classical biology for the corresponding molecular plan. It is concerned particularly with the forms of biological molecules and […] is predominantly three-dimensional and structural—which does not mean, however, that it is merely a refinement of morphology. It must at the same time inquire into genesis and function.
Researchers in molecular biology use specific techniques native to molecular biology, but increasingly combine these with techniques and ideas from genetics and biochemistry. There is not a defined line between these disciplines.
Biochemistry is the study of the chemical substances and vital processes occurring in living organisms. Biochemists focus heavily on the role, function, and structure of biomolecules. The study of the chemistry behind biological processes and the synthesis of biologically active molecules are examples of biochemistry.
Genetics is the study of the effect of genetic differences on organisms. Often this can be inferred by the absence of a normal component (e.g. one gene). The study of “mutants” – organisms which lack one or more functional components with respect to the so-called “wild type” or normal phenotype. Genetic interactions (epistasis) can often confound simple interpretations of such “knock-out” studies.
Molecular biology is the study of molecular underpinnings of the processes of replication, transcription, translation, and cell function. The central dogma of molecular biology where genetic material is transcribed into RNA and then translated into protein, despite being an oversimplified picture of molecular biology, still provides a good starting point for understanding the field. This picture, however, is undergoing revision in light of emerging novel roles for RNA.
Much of the work in molecular biology is quantitative, and recently much work has been done at the interface of molecular biology and computer science in bioinformatics and computational biology. As of the early 2000s, the study of gene structure and function, molecular genetics, has been among the most prominent sub-field of molecular biology.
Increasingly many other loops of biology focus on molecules, by either directly studying their interactions in their own right such as in cell biology and developmental biology, or indirectly, where the techniques of molecular biology are used to infer historical attributes of populations or species, as in fields in evolutionary biology such as population genetics and phylogenetics. There is also a long tradition of studying biomolecules “from the ground up” in biophysics.
Telecommunication is the transmission of information, over significant distances, to communicate with others. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded drumbeats, lung-blown horns, or sent by loud whistles, for example. In modern ages of electricity and electronics, telecommunications now also includes the use of electrical devices such as telegraphs, telephones, and teletypes, the use of radio and microwave communications, as well as fiber optics and their associated electronics, plus the use of the orbiting satellites and the Internet.
The first breakthrough into modern electrical telecommunications came with the push to fully develop the telegraph starting in the 1830s. The use of these electrical means of communications expanded telecommunications to almost all locations of the world during the 19th century, and thereby connected the continents via cables on the floors of the ocean. The use of the first three popular systems of electrical telecommunications, ie the telegraph, telephone and teletype, all required the use of conducting metal wires.
A revolution in wireless telecommunications began in the first decade of the 20th century, with Guglielmo Marconi winning the Nobel Prize in Physics in 1909 for his pioneering developments in wireless radio communications. Other highly notable pioneering inventors and developers in the field of electrical and electronic telecommunications include Charles Wheatstone and Samuel Morse (telegraph), Alexander Graham Bell (telephone), Nikola Tesla, Edwin Armstrong, and Lee de Forest (radio), as well as John Logie Baird and Philo Farnsworth (television).
Telecommunications today comprise the large field of mobile and handheld devices which provide instant communication to other users and to the internet.
Telecommunications play an important role in the world economy. The worldwide telecom services market was valued at 1.66 trillion in 2020 and is expected to expand at a compound annual growth rate of above 5% from 2022 to 2028. Particularly implementation of 5G infrastructure due to the shift in customer inclination toward next-generation technologies and smartphone devices is one of the key factors for this development. An increasing number of mobile subscribers, increasing demand for high-speed data connections, and the growing demand for mobile managed services are additional factors.