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124-629: Isaac Asimov ( / ˈ æ z ɪ m ɒ v / AZ -ih-mov ; c.  January 2, 1920  – April 6, 1992) was an American writer and professor of biochemistry at Boston University . During his lifetime, Asimov was considered one of the "Big Three" science fiction writers, along with Robert A. Heinlein and Arthur C. Clarke . A prolific writer, he wrote or edited more than 500 books. He also wrote an estimated 90,000 letters and postcards . Best known for his hard science fiction , Asimov also wrote mysteries and fantasy , as well as popular science and other non-fiction . Asimov's most famous work

248-455: A Frankenstein plot in which they destroyed their creators. The Robot series has led to film adaptations. With Asimov's collaboration, in about 1977, Harlan Ellison wrote a screenplay of I, Robot that Asimov hoped would lead to "the first really adult, complex, worthwhile science fiction film ever made". The screenplay has never been filmed and was eventually published in book form in 1994. The 2004 movie I, Robot , starring Will Smith ,

372-494: A New York City Subway station, within which he could enclose himself and listen to the rumble of passing trains while reading. Asimov was afraid of flying , doing so only twice: once in the course of his work at the Naval Air Experimental Station and once returning home from Oʻahu in 1946. Consequently, he seldom traveled great distances. This phobia influenced several of his fiction works, such as

496-628: A biological polymer , they undergo a process called dehydration synthesis . Different macromolecules can assemble in larger complexes, often needed for biological activity . Two of the main functions of carbohydrates are energy storage and providing structure. One of the common sugars known as glucose is a carbohydrate, but not all carbohydrates are sugars. There are more carbohydrates on Earth than any other known type of biomolecule; they are used to store energy and genetic information , as well as play important roles in cell to cell interactions and communications . The simplest type of carbohydrate

620-433: A carboxylic acid group, –COOH (although these exist as –NH 3 and –COO under physiologic conditions), a simple hydrogen atom , and a side chain commonly denoted as "–R". The side chain "R" is different for each amino acid of which there are 20 standard ones . It is this "R" group that makes each amino acid different, and the properties of the side chains greatly influence the overall three-dimensional conformation of

744-399: A chemical theory of metabolism, or even earlier to the 18th century studies on fermentation and respiration by Antoine Lavoisier . Many other pioneers in the field who helped to uncover the layers of complexity of biochemistry have been proclaimed founders of modern biochemistry. Emil Fischer , who studied the chemistry of proteins , and F. Gowland Hopkins , who studied enzymes and

868-549: A civilian chemist at the Philadelphia Navy Yard 's Naval Air Experimental Station and lived in the Walnut Hill section of West Philadelphia . In September 1945, he was conscripted into the post-war U.S. Army ; if he had not had his birth date corrected while at school, he would have been officially 26 years old and ineligible. In 1946, a bureaucratic error caused his military allotment to be stopped, and he

992-479: A college-level textbook called Biochemistry and Human Metabolism . Following the brief orbit of the first human-made satellite Sputnik I by the USSR in 1957, he wrote more nonfiction, particularly popular science books, and less science fiction. Over the next quarter-century, he wrote only four science fiction novels, and 120 nonfiction books. Starting in 1982, the second half of his science fiction career began with

1116-434: A component of DNA . A monosaccharide can switch between acyclic (open-chain) form and a cyclic form. The open-chain form can be turned into a ring of carbon atoms bridged by an oxygen atom created from the carbonyl group of one end and the hydroxyl group of another. The cyclic molecule has a hemiacetal or hemiketal group, depending on whether the linear form was an aldose or a ketose . In these cyclic forms,

1240-607: A conversation with Campbell, Asimov wrote " Nightfall ", his 32nd story, in March and April 1941, and Astounding published it in September 1941. In 1968 the Science Fiction Writers of America voted "Nightfall" the best science fiction short story ever written. In Nightfall and Other Stories Asimov wrote, "The writing of 'Nightfall' was a watershed in my professional career ... I was suddenly taken seriously and

1364-406: A cyclic [ring] and planar [flat] structure) while others are not. Some are flexible, while others are rigid. Lipids are usually made from one molecule of glycerol combined with other molecules. In triglycerides , the main group of bulk lipids, there is one molecule of glycerol and three fatty acids . Fatty acids are considered the monomer in that case, and maybe saturated (no double bonds in

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1488-536: A father image". Asimov believed his most enduring contributions would be his " Three Laws of Robotics " and the Foundation series . The Oxford English Dictionary credits his science fiction for introducing into the English language the words " robotics ", " positronic " (an entirely fictional technology), and " psychohistory " (which is also used for a different study on historical motivations). Asimov coined

1612-468: A few (around three to six) monosaccharides are joined, it is called an oligosaccharide ( oligo- meaning "few"). These molecules tend to be used as markers and signals , as well as having some other uses. Many monosaccharides joined form a polysaccharide . They can be joined in one long linear chain, or they may be branched . Two of the most common polysaccharides are cellulose and glycogen , both consisting of repeating glucose monomers . Cellulose

1736-765: A full novel of 70,000 words. The book appeared under the Doubleday imprint in January 1950 with the title of Pebble in the Sky . Doubleday published five more original science fiction novels by Asimov in the 1950s, along with the six juvenile Lucky Starr novels , the latter under the pseudonym "Paul French". Doubleday also published collections of Asimov's short stories, beginning with The Martian Way and Other Stories in 1955. The early 1950s also saw Gnome Press publish one collection of Asimov's positronic robot stories as I, Robot and his Foundation stories and novelettes as

1860-417: A full-time writer. He later said that unlike other Golden Age writers Heinlein and A. E. van Vogt —also first published in 1939, and whose talent and stardom were immediately obvious—Asimov "(this is not false modesty) came up only gradually". Through July 29, 1940, Asimov wrote 22 stories in 25 months, of which 13 were published; he wrote in 1972 that from that date he never wrote a science fiction story that

1984-425: A historical way, going as far back as possible to a time when the science in question was at its simplest stage. Examples include Guide to Science , the three-volume Understanding Physics , and Asimov's Chronology of Science and Discovery . He wrote on numerous other scientific and non-scientific topics, such as chemistry , astronomy , mathematics , history , biblical exegesis , and literary criticism . He

2108-404: A molecule with a 5-membered ring, called glucofuranose . The same reaction can take place between carbons 1 and 5 to form a molecule with a 6-membered ring, called glucopyranose . Cyclic forms with a 7-atom ring called heptoses are rare. Two monosaccharides can be joined by a glycosidic or ester bond into a disaccharide through a dehydration reaction during which a molecule of water

2232-479: A paper to DARPA titled "On Creativity" containing ideas on how government-based science projects could encourage team members to think more creatively. Asimov met his first wife, Gertrude Blugerman (May 16, 1917, Toronto , Canada – October 17, 1990, Boston , U.S.), on a blind date on February 14, 1942, and married her on July 26. The couple lived in an apartment in West Philadelphia while Asimov

2356-463: A pleasant time is to go up to my attic, sit at my electric typewriter (as I am doing right now), and bang away, watching the words take shape like magic before my eyes. Asimov's career can be divided into several periods. His early career, dominated by science fiction, began with short stories in 1939 and novels in 1950. This lasted until about 1958, all but ending after publication of The Naked Sun (1957). He began publishing nonfiction as co-author of

2480-414: A protein. Some amino acids have functions by themselves or in a modified form; for instance, glutamate functions as an important neurotransmitter . Amino acids can be joined via a peptide bond . In this dehydration synthesis, a water molecule is removed and the peptide bond connects the nitrogen of one amino acid's amino group to the carbon of the other's carboxylic acid group. The resulting molecule

2604-412: A pseudonym. When it nevertheless appeared under his own name, Asimov grew concerned that his doctoral examiners might think he wasn't taking science seriously. At the end of the examination, one evaluator turned to him, smiling, and said, "What can you tell us, Mr. Asimov, about the thermodynamic properties of the compound known as thiotimoline". Laughing hysterically with relief, Asimov had to be led out of

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2728-566: A reducing end because of full acetal formation between the aldehyde carbon of glucose (C1) and the keto carbon of fructose (C2). Lipids comprise a diverse range of molecules and to some extent is a catchall for relatively water-insoluble or nonpolar compounds of biological origin, including waxes , fatty acids , fatty-acid derived phospholipids , sphingolipids , glycolipids , and terpenoids (e.g., retinoids and steroids ). Some lipids are linear, open-chain aliphatic molecules, while others have ring structures. Some are aromatic (with

2852-514: A strong formative influence on Asimov and became a personal friend. By the end of the month, Asimov completed a second story, " Stowaway ". Campbell rejected it on July 22 but—in "the nicest possible letter you could imagine"—encouraged him to continue writing, promising that Asimov might sell his work after another year and a dozen stories of practice. On October 21, 1938, he sold the third story he finished, " Marooned Off Vesta ", to Amazing Stories , edited by Raymond A. Palmer , and it appeared in

2976-440: A study of the components and composition of living things and how they come together to become life. In this sense, the history of biochemistry may therefore go back as far as the ancient Greeks . However, biochemistry as a specific scientific discipline began sometime in the 19th century, or a little earlier, depending on which aspect of biochemistry is being focused on. Some argued that the beginning of biochemistry may have been

3100-463: A used typewriter at age 16. His first published work was a humorous item on the birth of his brother for Boys High School's literary journal in 1934. In May 1937 he first thought of writing professionally, and began writing his first science fiction story, "Cosmic Corkscrew" (now lost), that year. On May 17, 1938, puzzled by a change in the schedule of Astounding Science Fiction , Asimov visited its publisher Street & Smith Publications . Inspired by

3224-518: A year. He expected to make chemistry his career, and was paid $ 2,600 annually at the Philadelphia Navy Yard, enough to marry his girlfriend; he did not expect to make much more from writing than the $ 1,788.50 he had earned from the 28 stories he had already sold over four years. Asimov left science fiction fandom and no longer read new magazines, and might have left the writing profession had not Heinlein and de Camp been his coworkers at

3348-431: Is a monosaccharide , which among other properties contains carbon , hydrogen , and oxygen , mostly in a ratio of 1:2:1 (generalized formula C n H 2 n O n , where n is at least 3). Glucose (C 6 H 12 O 6 ) is one of the most important carbohydrates; others include fructose (C 6 H 12 O 6 ), the sugar commonly associated with the sweet taste of fruits , and deoxyribose (C 5 H 10 O 4 ),

3472-412: Is an energy source in most life forms. For instance, polysaccharides are broken down into their monomers by enzymes ( glycogen phosphorylase removes glucose residues from glycogen, a polysaccharide). Disaccharides like lactose or sucrose are cleaved into their two component monosaccharides. Glucose is mainly metabolized by a very important ten-step pathway called glycolysis , the net result of which

3596-407: Is an important structural component of plant's cell walls and glycogen is used as a form of energy storage in animals. Sugar can be characterized by having reducing or non-reducing ends. A reducing end of a carbohydrate is a carbon atom that can be in equilibrium with the open-chain aldehyde ( aldose ) or keto form ( ketose ). If the joining of monomers takes place at such a carbon atom,

3720-424: Is called a dipeptide , and short stretches of amino acids (usually, fewer than thirty) are called peptides or polypeptides . Longer stretches merit the title proteins . As an example, the important blood serum protein albumin contains 585 amino acid residues . Proteins can have structural and/or functional roles. For instance, movements of the proteins actin and myosin ultimately are responsible for

3844-421: Is not an essential element for plants. Plants need boron and silicon , but animals may not (or may need ultra-small amounts). Just six elements— carbon , hydrogen , nitrogen , oxygen , calcium and phosphorus —make up almost 99% of the mass of living cells, including those in the human body (see composition of the human body for a complete list). In addition to the six major elements that compose most of

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3968-508: Is released. The reverse reaction in which the glycosidic bond of a disaccharide is broken into two monosaccharides is termed hydrolysis . The best-known disaccharide is sucrose or ordinary sugar , which consists of a glucose molecule and a fructose molecule joined. Another important disaccharide is lactose found in milk, consisting of a glucose molecule and a galactose molecule. Lactose may be hydrolysed by lactase , and deficiency in this enzyme results in lactose intolerance . When

4092-583: Is the Foundation series, the first three books of which won the one-time Hugo Award for "Best All-Time Series" in 1966. His other major series are the Galactic Empire series and the Robot series. The Galactic Empire novels are set in the much earlier history of the same fictional universe as the Foundation series. Later, with Foundation and Earth (1986), he linked this distant future to

4216-506: Is the generic name of the family of biopolymers . They are complex, high-molecular-weight biochemical macromolecules that can convey genetic information in all living cells and viruses. The monomers are called nucleotides , and each consists of three components: a nitrogenous heterocyclic base (either a purine or a pyrimidine ), a pentose sugar, and a phosphate group. The most common nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). The phosphate group and

4340-492: Is thought to be the reason why complex life appeared only after Earth's atmosphere accumulated large amounts of oxygen. In vertebrates , vigorously contracting skeletal muscles (during weightlifting or sprinting, for example) do not receive enough oxygen to meet the energy demand, and so they shift to anaerobic metabolism , converting glucose to lactate. The combination of glucose from noncarbohydrates origin, such as fat and proteins. This only happens when glycogen supplies in

4464-409: Is to break down one molecule of glucose into two molecules of pyruvate . This also produces a net two molecules of ATP , the energy currency of cells, along with two reducing equivalents of converting NAD (nicotinamide adenine dinucleotide: oxidized form) to NADH (nicotinamide adenine dinucleotide: reduced form). This does not require oxygen; if no oxygen is available (or the cell cannot use oxygen),

4588-634: The Columbia University School of General Studies ) in 1939. After two rounds of rejections by medical schools, Asimov applied to the graduate program in chemistry at Columbia in 1939; initially he was rejected and then only accepted on a probationary basis. He completed his Master of Arts degree in chemistry in 1941 and earned a Doctor of Philosophy degree in chemistry in 1948. During his chemistry studies, he also learned French and German. From 1942 to 1945 during World War II , between his masters and doctoral studies, Asimov worked as

4712-686: The Committee for Skeptical Inquiry ) and is listed in its Pantheon of Skeptics. In a discussion with James Randi at CSICon 2016 regarding the founding of CSICOP, Kendrick Frazier said that Asimov was "a key figure in the Skeptical movement who is less well known and appreciated today, but was very much in the public eye back then." He said that Asimov's being associated with CSICOP "gave it immense status and authority" in his eyes. Asimov described Carl Sagan as one of only two people he ever met whose intellect surpassed his own. The other, he claimed,

4836-540: The Latin alphabet , Asimov's father spelled it with an S, believing this letter to be pronounced like Z (as in German), and so it became Asimov. This later inspired one of Asimov's short stories, " Spell My Name with an S ". Asimov refused early suggestions of using a more common name as a pseudonym, believing that its recognizability helped his career. After becoming famous, he often met readers who believed that "Isaac Asimov"

4960-578: The Robot series, creating a unified " future history " for his works. He also wrote more than 380 short stories , including the social science fiction novelette " Nightfall ", which in 1964 was voted the best short science fiction story of all time by the Science Fiction Writers of America . Asimov wrote the Lucky Starr series of juvenile science-fiction novels using the pen name Paul French. Most of his popular science books explain concepts in

5084-603: The SS ; France for a trip mostly devoted to lectures in London and Birmingham, though he also found time to visit Stonehenge and Shakespeare's birthplace. Asimov was a teetotaler . He was an able public speaker and was regularly invited to give talks about science in his distinct New York accent . He participated in many science fiction conventions , where he was friendly and approachable. He patiently answered tens of thousands of questions and other mail with postcards and

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5208-1003: The Trap Door Spiders , which served as the basis of his fictional group of mystery solvers, the Black Widowers . He later used his essay on Moriarty's work as the basis for a Black Widowers story, " The Ultimate Crime ", which appeared in More Tales of the Black Widowers . In 1984, the American Humanist Association (AHA) named him the Humanist of the Year. He was one of the signers of the Humanist Manifesto . From 1985 until his death in 1992, he served as honorary president of

5332-465: The Upper West Side of Manhattan where he lived for the rest of his life. He began seeing Janet O. Jeppson , a psychiatrist and science-fiction writer, and married her on November 30, 1973, two weeks after his divorce from Gertrude. Asimov was a claustrophile : he enjoyed small, enclosed spaces. In the third volume of his autobiography, he recalls a childhood desire to own a magazine stand in

5456-634: The Wendell Urth mystery stories and the Robot novels featuring Elijah Baley . In his later years, Asimov found enjoyment traveling on cruise ships , beginning in 1972 when he viewed the Apollo 17 launch from a cruise ship . On several cruises, he was part of the entertainment program, giving science-themed talks aboard ships such as the Queen Elizabeth 2 . He sailed to England in June 1974 on

5580-630: The border between Belarus and Russia . Its population in 1998 was 215. The village is the birthplace of Isaac Asimov . Asimov left it at the age of three, with his parents and sister, emigrating to the United States . There is a stone memorial at the site of his birth. The earliest recorded mention of Petrovichi is from 1403. In the Russian Empire , Petrovichi was a shtetl in Klimovichskiy Uyezd (an uyezd with

5704-748: The chemistry required for biological activity of molecules, molecular biology studies their biological activity, genetics studies their heredity, which happens to be carried by their genome . This is shown in the following schematic that depicts one possible view of the relationships between the fields: Petrovichi Petrovichi ( Russian : Петро́вичи ) is a rural locality (a village ) in Shumyachsky District of Smolensk Oblast , Russia , located about 400 kilometers (250 mi) southwest of Moscow , 668 kilometers (415 mi) south of St Petersburg , 100 kilometers (62 mi) south of Smolensk , and 16 kilometers (9.9 mi) east of

5828-434: The comic operas of Gilbert and Sullivan . Many of his short stories mention or quote Gilbert and Sullivan. He was a prominent member of The Baker Street Irregulars , the leading Sherlock Holmes society, for whom he wrote an essay arguing that Professor Moriarty's work "The Dynamics of An Asteroid" involved the willful destruction of an ancient, civilized planet. He was also a member of the male-only literary banqueting club

5952-416: The essential amino acids . Mammals do possess the enzymes to synthesize alanine , asparagine , aspartate , cysteine , glutamate , glutamine , glycine , proline , serine , and tyrosine , the nonessential amino acids. While they can synthesize arginine and histidine , they cannot produce it in sufficient amounts for young, growing animals, and so these are often considered essential amino acids. If

6076-424: The glutamate residue at position 6 with a valine residue changes the behavior of hemoglobin so much that it results in sickle-cell disease . Finally, quaternary structure is concerned with the structure of a protein with multiple peptide subunits, like hemoglobin with its four subunits. Not all proteins have more than one subunit. Ingested proteins are usually broken up into single amino acids or dipeptides in

6200-572: The pulp magazines sold in his family's candy store. At first his father forbade reading pulps until Asimov persuaded him that because the science fiction magazines had "Science" in the title, they must be educational. At age 18 he joined the Futurians science fiction fan club , where he made friends who went on to become science fiction writers or editors. Asimov began writing at the age of 11, imitating The Rover Boys with eight chapters of The Greenville Chums at College . His father bought him

6324-406: The second grade ). His mother got him into first grade a year early by claiming he was born on September 7, 1919. In third grade he learned about the "error" and insisted on an official correction of the date to January 2. He became a naturalized U.S. citizen in 1928 at the age of eight. After becoming established in the U.S., his parents owned a succession of candy stores in which everyone in

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6448-549: The small intestine and then absorbed. They can then be joined to form new proteins. Intermediate products of glycolysis, the citric acid cycle, and the pentose phosphate pathway can be used to form all twenty amino acids, and most bacteria and plants possess all the necessary enzymes to synthesize them. Humans and other mammals, however, can synthesize only half of them. They cannot synthesize isoleucine , leucine , lysine , methionine , phenylalanine , threonine , tryptophan , and valine . Because they must be ingested, these are

6572-399: The " vital principle ") distinct from any found in non-living matter, and it was thought that only living beings could produce the molecules of life. In 1828, Friedrich Wöhler published a paper on his serendipitous urea synthesis from potassium cyanate and ammonium sulfate ; some regarded that as a direct overthrow of vitalism and the establishment of organic chemistry . However,

6696-415: The 100s category, but none of his own books were classified in that category. According to UNESCO 's Index Translationum database , Asimov is the world's 24th-most-translated author. No matter how various the subject matter I write on, I was a science-fiction writer first and it is as a science-fiction writer that I want to be identified. Asimov became a science fiction fan in 1929, when he began reading

6820-641: The AHA, and was succeeded by his friend and fellow writer Kurt Vonnegut . He was also a close friend of Star Trek creator Gene Roddenberry , and earned a screen credit as "special science consultant" on Star Trek: The Motion Picture for his advice during production. Asimov was a founding member of the Committee for the Scientific Investigation of Claims of the Paranormal, CSICOP (now

6944-751: The March 1939 issue. Asimov was paid $ 64 (equivalent to $ 1,385 in 2023), or one cent a word. Two more stories appeared that year, " The Weapon Too Dreadful to Use " in the May Amazing and " Trends " in the July Astounding , the issue fans later selected as the start of the Golden Age of Science Fiction . For 1940, ISFDB catalogs seven stories in four different pulp magazines, including one in Astounding . His earnings became enough to pay for his education, but not yet enough for him to become

7068-518: The N-terminal domain. The enzyme-linked immunosorbent assay (ELISA), which uses antibodies, is one of the most sensitive tests modern medicine uses to detect various biomolecules. Probably the most important proteins, however, are the enzymes . Virtually every reaction in a living cell requires an enzyme to lower the activation energy of the reaction. These molecules recognize specific reactant molecules called substrates ; they then catalyze

7192-492: The NAD is restored by converting the pyruvate to lactate (lactic acid) (e.g. in humans) or to ethanol plus carbon dioxide (e.g. in yeast ). Other monosaccharides like galactose and fructose can be converted into intermediates of the glycolytic pathway. In aerobic cells with sufficient oxygen , as in most human cells, the pyruvate is further metabolized. It is irreversibly converted to acetyl-CoA , giving off one carbon atom as

7316-516: The Navy Yard and previously sold stories continued to appear. In 1942, Asimov published the first of his Foundation stories—later collected in the Foundation trilogy : Foundation (1951), Foundation and Empire (1952), and Second Foundation (1953). The books describe the fall of a vast interstellar empire and the establishment of its eventual successor. They feature his fictional science of psychohistory , whose theories could predict

7440-656: The United States via Liverpool on the RMS Baltic , arriving on February 3, 1923 when he was three years old. His parents spoke Yiddish and English to him; he never learned Russian , his parents using it as a secret language "when they wanted to discuss something privately that my big ears were not to hear". Growing up in Brooklyn , New York , Asimov taught himself to read at the age of five (and later taught his sister to read as well, enabling her to enter school in

7564-485: The Wöhler synthesis has sparked controversy as some reject the death of vitalism at his hands. Since then, biochemistry has advanced, especially since the mid-20th century, with the development of new techniques such as chromatography , X-ray diffraction , dual polarisation interferometry , NMR spectroscopy , radioisotopic labeling , electron microscopy and molecular dynamics simulations. These techniques allowed for

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7688-487: The academically qualified Jewish and Italian-American students who applied to the more prestigious Columbia College , but exceeded the unwritten ethnic admission quotas which were common at the time. Originally a zoology major, Asimov switched to chemistry after his first semester because he disapproved of "dissecting an alley cat". After Seth Low Junior College closed in 1936, Asimov finished his Bachelor of Science degree at Columbia's Morningside Heights campus (later

7812-416: The amino group is removed from an amino acid, it leaves behind a carbon skeleton called an α- keto acid . Enzymes called transaminases can easily transfer the amino group from one amino acid (making it an α-keto acid) to another α-keto acid (making it an amino acid). This is important in the biosynthesis of amino acids, as for many of the pathways, intermediates from other biochemical pathways are converted to

7936-434: The amount of energy gained from glycolysis (six molecules of ATP are used, compared to the two gained in glycolysis). Analogous to the above reactions, the glucose produced can then undergo glycolysis in tissues that need energy, be stored as glycogen (or starch in plants), or be converted to other monosaccharides or joined into di- or oligosaccharides. The combined pathways of glycolysis during exercise, lactate's crossing via

8060-878: The animals' needs. Unicellular organisms release the ammonia into the environment. Likewise, bony fish can release ammonia into the water where it is quickly diluted. In general, mammals convert ammonia into urea, via the urea cycle . In order to determine whether two proteins are related, or in other words to decide whether they are homologous or not, scientists use sequence-comparison methods. Methods like sequence alignments and structural alignments are powerful tools that help scientists identify homologies between related molecules. The relevance of finding homologies among proteins goes beyond forming an evolutionary pattern of protein families . By finding how similar two protein sequences are, we acquire knowledge about their structure and therefore their function. Nucleic acids , so-called because of their prevalence in cellular nuclei ,

8184-442: The blessing of, or at the request of, Asimov's widow, Janet Asimov . In 1948, he also wrote a spoof chemistry article , " The Endochronic Properties of Resublimated Thiotimoline ". At the time, Asimov was preparing his own doctoral dissertation , which would include an oral examination. Fearing a prejudicial reaction from his graduate school evaluation board at Columbia University , Asimov asked his editor that it be released under

8308-468: The bloodstream to the liver, subsequent gluconeogenesis and release of glucose into the bloodstream is called the Cori cycle . Researchers in biochemistry use specific techniques native to biochemistry, but increasingly combine these with techniques and ideas developed in the fields of genetics , molecular biology , and biophysics . There is not a defined line between these disciplines. Biochemistry studies

8432-513: The body and are broken into fatty acids and glycerol, the final degradation products of fats and lipids. Lipids, especially phospholipids , are also used in various pharmaceutical products , either as co-solubilizers (e.g. in parenteral infusions) or else as drug carrier components (e.g. in a liposome or transfersome ). Proteins are very large molecules—macro-biopolymers—made from monomers called amino acids . An amino acid consists of an alpha carbon atom attached to an amino group, –NH 2 ,

8556-479: The border marker from the west to the east of the shtetl . Thus he saved half of the people from much suffering, as well as saving himself from losing their talents and skills. Petrovichi was an important hub of the wheat trade, and Jewish traders in wheat were respected for their honesty and efficiency. Petrovichi was part of Belarus for several decades. During the Soviet times, restrictions were no longer imposed on

8680-539: The carbon chain) or unsaturated (one or more double bonds in the carbon chain). Most lipids have some polar character and are largely nonpolar. In general, the bulk of their structure is nonpolar or hydrophobic ("water-fearing"), meaning that it does not interact well with polar solvents like water . Another part of their structure is polar or hydrophilic ("water-loving") and will tend to associate with polar solvents like water. This makes them amphiphilic molecules (having both hydrophobic and hydrophilic portions). In

8804-490: The case of cholesterol , the polar group is a mere –OH (hydroxyl or alcohol). In the case of phospholipids, the polar groups are considerably larger and more polar, as described below. Lipids are an integral part of our daily diet. Most oils and milk products that we use for cooking and eating like butter , cheese , ghee etc. are composed of fats . Vegetable oils are rich in various polyunsaturated fatty acids (PUFA). Lipid-containing foods undergo digestion within

8928-651: The causes and cures of diseases . Nutrition studies how to maintain health and wellness and also the effects of nutritional deficiencies . In agriculture, biochemists investigate soil and fertilizers with the goal of improving crop cultivation, crop storage, and pest control . In recent decades, biochemical principles and methods have been combined with problem-solving approaches from engineering to manipulate living systems in order to produce useful tools for research, industrial processes, and diagnosis and control of disease—the discipline of biotechnology . At its most comprehensive definition, biochemistry can be seen as

9052-488: The cell also depends upon the reactions of small molecules and ions . These can be inorganic (for example, water and metal ions) or organic (for example, the amino acids , which are used to synthesize proteins ). The mechanisms used by cells to harness energy from their environment via chemical reactions are known as metabolism . The findings of biochemistry are applied primarily in medicine , nutrition and agriculture . In medicine, biochemists investigate

9176-507: The contraction of skeletal muscle. One property many proteins have is that they specifically bind to a certain molecule or class of molecules—they may be extremely selective in what they bind. Antibodies are an example of proteins that attach to one specific type of molecule. Antibodies are composed of heavy and light chains. Two heavy chains would be linked to two light chains through disulfide linkages between their amino acids. Antibodies are specific through variation based on differences in

9300-591: The discovery and detailed analysis of many molecules and metabolic pathways of the cell , such as glycolysis and the Krebs cycle (citric acid cycle), and led to an understanding of biochemistry on a molecular level. Another significant historic event in biochemistry is the discovery of the gene , and its role in the transfer of information in the cell. In the 1950s, James D. Watson , Francis Crick , Rosalind Franklin and Maurice Wilkins were instrumental in solving DNA structure and suggesting its relationship with

9424-492: The discovery of the first enzyme , diastase (now called amylase ), in 1833 by Anselme Payen , while others considered Eduard Buchner 's first demonstration of a complex biochemical process alcoholic fermentation in cell-free extracts in 1897 to be the birth of biochemistry. Some might also point as its beginning to the influential 1842 work by Justus von Liebig , Animal chemistry, or, Organic chemistry in its applications to physiology and pathology , which presented

9548-466: The dynamic nature of biochemistry, represent two examples of early biochemists. The term "biochemistry" was first used when Vinzenz Kletzinsky (1826–1882) had his "Compendium der Biochemie" printed in Vienna in 1858; it derived from a combination of biology and chemistry . In 1877, Felix Hoppe-Seyler used the term ( biochemie in German) as a synonym for physiological chemistry in the foreword to

9672-554: The electrons from high-energy states in NADH and quinol is conserved first as proton gradient and converted to ATP via ATP synthase. This generates an additional 28 molecules of ATP (24 from the 8 NADH + 4 from the 2 quinols), totaling to 32 molecules of ATP conserved per degraded glucose (two from glycolysis + two from the citrate cycle). It is clear that using oxygen to completely oxidize glucose provides an organism with far more energy than any oxygen-independent metabolic feature, and this

9796-426: The enzyme can be regulated, enabling control of the biochemistry of the cell as a whole. The structure of proteins is traditionally described in a hierarchy of four levels. The primary structure of a protein consists of its linear sequence of amino acids; for instance, "alanine-glycine-tryptophan-serine-glutamate-asparagine-glycine-lysine-...". Secondary structure is concerned with local morphology (morphology being

9920-469: The enzyme complexes of the respiratory chain, an electron transport system transferring the electrons ultimately to oxygen and conserving the released energy in the form of a proton gradient over a membrane ( inner mitochondrial membrane in eukaryotes). Thus, oxygen is reduced to water and the original electron acceptors NAD and quinone are regenerated. This is why humans breathe in oxygen and breathe out carbon dioxide. The energy released from transferring

10044-399: The family was expected to work. The candy stores sold newspapers and magazines, which Asimov credited as a major influence in his lifelong love of the written word, as it presented him as a child with an unending supply of new reading material (including pulp science fiction magazines ) that he could not have otherwise afforded. Asimov began reading science fiction at age nine, at the time that

10168-448: The first issue of Zeitschrift für Physiologische Chemie (Journal of Physiological Chemistry) where he argued for the setting up of institutes dedicated to this field of study. The German chemist Carl Neuberg however is often cited to have coined the word in 1903, while some credited it to Franz Hofmeister . It was once generally believed that life and its materials had some essential property or substance (often referred to as

10292-516: The first-season episode " Datalore " called the positronic brain "Asimov's dream". Asimov was so prolific and diverse in his writing that his books span all major categories of the Dewey Decimal Classification except for category 100, philosophy and psychology . However, he wrote several essays about psychology, and forewords for the books The Humanist Way (1988) and In Pursuit of Truth (1982), which were classified in

10416-467: The free hydroxy group of the pyranose or furanose form is exchanged with an OH-side-chain of another sugar, yielding a full acetal . This prevents opening of the chain to the aldehyde or keto form and renders the modified residue non-reducing. Lactose contains a reducing end at its glucose moiety, whereas the galactose moiety forms a full acetal with the C4-OH group of glucose. Saccharose does not have

10540-564: The future course of history according to dynamical laws regarding the statistical analysis of mass human actions. Campbell raised his rate per word, Orson Welles purchased rights to " Evidence ", and anthologies reprinted his stories. By the end of the war Asimov was earning as a writer an amount equal to half of his Navy Yard salary, even after a raise, but Asimov still did not believe that writing could support him, his wife, and future children. His "positronic" robot stories —many of which were collected in I, Robot (1950)—were begun at about

10664-531: The genetic material of the cell, nucleic acids often play a role as second messengers , as well as forming the base molecule for adenosine triphosphate (ATP), the primary energy-carrier molecule found in all living organisms. Also, the nitrogenous bases possible in the two nucleic acids are different: adenine, cytosine, and guanine occur in both RNA and DNA, while thymine occurs only in DNA and uracil occurs in RNA. Glucose

10788-526: The genetic transfer of information. In 1958, George Beadle and Edward Tatum received the Nobel Prize for work in fungi showing that one gene produces one enzyme . In 1988, Colin Pitchfork was the first person convicted of murder with DNA evidence, which led to the growth of forensic science . More recently, Andrew Z. Fire and Craig C. Mello received the 2006 Nobel Prize for discovering

10912-680: The genre was becoming more science-centered. Asimov was also a frequent patron of the Brooklyn Public Library during his formative years. Asimov attended New York City public schools from age five, including Boys High School in Brooklyn . Graduating at 15, he attended the City College of New York for several days before accepting a scholarship at Seth Low Junior College . This was a branch of Columbia University in Downtown Brooklyn designed to absorb some of

11036-448: The human body, humans require smaller amounts of possibly 18 more. The 4 main classes of molecules in biochemistry (often called biomolecules ) are carbohydrates , lipids , proteins , and nucleic acids . Many biological molecules are polymers : in this terminology, monomers are relatively small macromolecules that are linked together to create large macromolecules known as polymers. When monomers are linked together to synthesize

11160-458: The liver are worn out. The pathway is a crucial reversal of glycolysis from pyruvate to glucose and can use many sources like amino acids, glycerol and Krebs Cycle . Large scale protein and fat catabolism usually occur when those suffer from starvation or certain endocrine disorders. The liver regenerates the glucose, using a process called gluconeogenesis . This process is not quite the opposite of glycolysis, and actually requires three times

11284-434: The publication of Foundation's Edge . From then until his death, Asimov published several more sequels and prequels to his existing novels, tying them together in a way he had not originally anticipated, making a unified series. There are many inconsistencies in this unification, especially in his earlier stories. Doubleday and Houghton Mifflin published about 60% of his work up to 1969, Asimov stating that "both represent

11408-410: The reaction between them. By lowering the activation energy , the enzyme speeds up that reaction by a rate of 10 or more; a reaction that would normally take over 3,000 years to complete spontaneously might take less than a second with an enzyme. The enzyme itself is not used up in the process and is free to catalyze the same reaction with a new set of substrates. Using various modifiers, the activity of

11532-413: The ring usually has 5 or 6 atoms. These forms are called furanoses and pyranoses , respectively—by analogy with furan and pyran , the simplest compounds with the same carbon-oxygen ring (although they lack the carbon-carbon double bonds of these two molecules). For example, the aldohexose glucose may form a hemiacetal linkage between the hydroxyl on carbon 1 and the oxygen on carbon 4, yielding

11656-559: The role of RNA interference (RNAi) in the silencing of gene expression . Around two dozen chemical elements are essential to various kinds of biological life . Most rare elements on Earth are not needed by life (exceptions being selenium and iodine ), while a few common ones ( aluminum and titanium ) are not used. Most organisms share element needs, but there are a few differences between plants and animals . For example, ocean algae use bromine , but land plants and animals do not seem to need any. All animals require sodium , but

11780-410: The room. After a five-minute wait, he was summoned back into the room and congratulated as "Dr. Asimov". Demand for science fiction greatly increased during the 1950s, making it possible for a genre author to write full-time. In 1949, book publisher Doubleday 's science fiction editor Walter I. Bradbury accepted Asimov's unpublished "Grow Old with Me" (40,000 words), but requested that it be extended to

11904-401: The same time. They promulgated a set of rules of ethics for robots (see Three Laws of Robotics ) and intelligent machines that greatly influenced other writers and thinkers in their treatment of the subject. Asimov notes in his introduction to the short story collection The Complete Robot (1982) that he was largely inspired by the tendency of robots up to that time to fall consistently into

12028-541: The seat in Klimovichi ) of Mogilev Governorate . The governorate, historically Belarusian land, was a part of the Empire's Northwestern Krai . Petrovichi's population was half Jewish , half Belarusian . It had both a church and a synagogue , each one with a school attached to it. According to Asimov's memoirs, the place had never known of pogroms . There were amicable business connections and even friendships between

12152-630: The settlement of Jewish people. The village became a part of the Russian SFSR and briefly belonged to Gomel Governorate before being transferred to Smolensk Oblast . The population dwindled significantly. In 1921, Isaac Asimov and 16 other children in Petrovichi developed double pneumonia . Only Asimov survived. In July 1941, Petrovichi was occupied by the German armies. 416 Jewish inhabitants who did not flee in time were massacred. It

12276-476: The study of structure). Some combinations of amino acids will tend to curl up in a coil called an α-helix or into a sheet called a β-sheet ; some α-helixes can be seen in the hemoglobin schematic above. Tertiary structure is the entire three-dimensional shape of the protein. This shape is determined by the sequence of amino acids. In fact, a single change can change the entire structure. The alpha chain of hemoglobin contains 146 amino acid residues; substitution of

12400-683: The sugar of each nucleotide bond with each other to form the backbone of the nucleic acid, while the sequence of nitrogenous bases stores the information. The most common nitrogenous bases are adenine , cytosine , guanine , thymine , and uracil . The nitrogenous bases of each strand of a nucleic acid will form hydrogen bonds with certain other nitrogenous bases in a complementary strand of nucleic acid. Adenine binds with thymine and uracil, thymine binds only with adenine, and cytosine and guanine can bind only with one another. Adenine, thymine, and uracil contain two hydrogen bonds, while hydrogen bonds formed between cytosine and guanine are three. Aside from

12524-410: The term "robotics" without suspecting that it might be an original word; at the time, he believed it was simply the natural analogue of words such as mechanics and hydraulics , but for robots . Unlike his word "psychohistory", the word "robotics" continues in mainstream technical use with Asimov's original definition. Star Trek: The Next Generation featured androids with " positronic brains " and

12648-498: The three books of the Foundation trilogy . More positronic robot stories were republished in book form as The Rest of the Robots . Biochemistry Much of biochemistry deals with the structures, functions, and interactions of biological macromolecules such as proteins , nucleic acids , carbohydrates , and lipids . They provide the structure of cells and perform many of the functions associated with life. The chemistry of

12772-636: The two communities. Asimov even reports non-Jews paying friendly visits to the local synagogue. Tsar Nicholas I (who ruled from 1825 to 1855) at one point ordered the expulsion of all Jewish people who resided in Great Russia , or Russia proper, outside of the Pale of Settlement . However, a rich and powerful Russian landlord, who owned much land on both sides of the border, saved the Jewish community of Petrovichi from " ethnic cleansing " by illegally moving

12896-534: The two h's and say it again and you have Asimov. Asimov's family name derives from the first part of озимый хлеб ( ozímyj khleb ), meaning ' winter grain ' (specifically rye ) in which his great-great-great-grandfather dealt, with the Russian surname ending -ov added. Azimov is spelled Азимов in the Cyrillic alphabet . When the family arrived in the United States in 1923 and their name had to be spelled in

13020-495: The university's Mugar Memorial Library , to which he donated them at the request of curator Howard Gotlieb. In 1959, after a recommendation from Arthur Obermayer , Asimov's friend and a scientist on the U.S. missile defense project, Asimov was approached by DARPA to join Obermayer's team. Asimov declined on the grounds that his ability to write freely would be impaired should he receive classified information , but submitted

13144-485: The visit, he finished the story on June 19, 1938, and personally submitted it to Astounding editor John W. Campbell two days later. Campbell met with Asimov for more than an hour and promised to read the story himself. Two days later he received a detailed rejection letter. This was the first of what became almost weekly meetings with the editor while Asimov lived in New York, until moving to Boston in 1949; Campbell had

13268-425: The waste product carbon dioxide , generating another reducing equivalent as NADH . The two molecules acetyl-CoA (from one molecule of glucose) then enter the citric acid cycle , producing two molecules of ATP, six more NADH molecules and two reduced (ubi)quinones (via FADH 2 as enzyme-bound cofactor), and releasing the remaining carbon atoms as carbon dioxide. The produced NADH and quinol molecules then feed into

13392-504: The world of science fiction became aware that I existed. As the years passed, in fact, it became evident that I had written a 'classic'." "Nightfall" is an archetypal example of social science fiction , a term he created to describe a new trend in the 1940s, led by authors including him and Heinlein, away from gadgets and space opera and toward speculation about the human condition . After writing " Victory Unintentional " in January and February 1942, Asimov did not write another story for

13516-474: The α-keto acid skeleton, and then an amino group is added, often via transamination . The amino acids may then be linked together to form a protein. A similar process is used to break down proteins. It is first hydrolyzed into its component amino acids. Free ammonia (NH3), existing as the ammonium ion (NH4+) in blood, is toxic to life forms. A suitable method for excreting it must therefore exist. Different tactics have evolved in different animals, depending on

13640-546: Was a distinctive pseudonym created by an author with a common name. Asimov was born in Petrovichi , Russian SFSR , on an unknown date between October 4, 1919, and January 2, 1920, inclusive. Asimov celebrated his birthday on January 2. Asimov's parents were Russian Jews , Anna Rachel (née Berman) and Judah Asimov, the son of a miller. He was named Isaac after his mother's father, Isaac Berman. Asimov wrote of his father, "My father, for all his education as an Orthodox Jew ,

13764-715: Was adapted into the 1999 movie Bicentennial Man , starring Robin Williams . In 1966 the Foundation trilogy won the Hugo Award for the all-time best series of science fiction and fantasy novels, and they along with the Robot series are his most famous science fiction. Besides movies, his Foundation and Robot stories have inspired other derivative works of science fiction literature, many by well-known and established authors such as Roger MacBride Allen , Greg Bear , Gregory Benford , David Brin , and Donald Kingsbury . At least some of these appear to have been done with

13888-421: Was based on an unrelated script by Jeff Vintar titled Hardwired , with Asimov's ideas incorporated later after the rights to Asimov's title were acquired. (The title was not original to Asimov but had previously been used for a story by Eando Binder .) Also, one of Asimov's robot short stories, " The Bicentennial Man ", was expanded into a novel The Positronic Man by Asimov and Robert Silverberg , and this

14012-476: Was cremated. The cause of death was reported as heart and kidney failure . Ten years following Asimov's death, Janet and Robyn Asimov agreed that the HIV story should be made public; Janet revealed it in her edition of his autobiography, It's Been a Good Life . [T]he only thing about myself that I consider to be severe enough to warrant psychoanalytic treatment is my compulsion to write ... That means that my idea of

14136-435: Was dismissed from his teaching post, with effect from June 30, 1958, due to his lack of research. After a struggle over two years, he reached an agreement with the university that he would keep his title and give the opening lecture each year for a biochemistry class. On October 18, 1979, the university honored his writing by promoting him to full professor of biochemistry. Asimov's personal papers from 1965 onward are archived at

14260-671: Was employed at the Philadelphia Navy Yard (where two of his co-workers were L. Sprague de Camp and Robert A. Heinlein ). Gertrude returned to Brooklyn while he was in the army, and they both lived there from July 1946 before moving to Stuyvesant Town , Manhattan , in July 1948. They moved to Boston in May 1949, then to nearby suburbs Somerville in July 1949, Waltham in May 1951, and, finally, West Newton in 1956. They had two children, David (born 1951) and Robyn Joan (born 1955). In 1970, they separated and Asimov moved back to New York, this time to

14384-407: Was in large part due to his years-long correspondence with William Boyd , a former associate professor of biochemistry at Boston University, who initially contacted Asimov to compliment him on his story Nightfall . Upon receiving a promotion to professor of immunochemistry , Boyd reached out to Asimov, requesting him to be his replacement. The initial offer of professorship was withdrawn and Asimov

14508-576: Was named by Carnegie Corporation of New York to the inaugural class of winners of the Great Immigrants Award . In 1977, Asimov had a heart attack . In December 1983, he had triple bypass surgery at NYU Medical Center, during which he contracted HIV from a blood transfusion . His HIV status was kept secret out of concern that the anti-AIDS prejudice might extend to his family members. He died in Manhattan on April 6, 1992, and

14632-509: Was not Orthodox in his heart", noting that "he didn't recite the myriad prayers prescribed for every action , and he never made any attempt to teach them to me." In 1921, Asimov and 16 other children in Petrovichi developed double pneumonia . Only Asimov survived. He had two younger siblings: a sister, Marcia (born Manya; June 17, 1922 – April 2, 2011), and a brother, Stanley (July 25, 1929 – August 16, 1995), who would become vice-president of Newsday . Asimov's family travelled to

14756-539: Was not published (except for two "special cases"). By 1941 Asimov was famous enough that Donald Wollheim told him that he purchased " The Secret Sense " for a new magazine only because of his name, and the December 1940 issue of Astonishing —featuring Asimov's name in bold—was the first magazine to base cover art on his work, but Asimov later said that neither he nor anyone else—except perhaps Campbell—considered him better than an often published "third rater". Based on

14880-467: Was offered the position of instructor of biochemistry instead, which he accepted. He began work in 1949 with a $ 5,000 salary (equivalent to $ 64,000 in 2023), maintaining this position for several years. By 1952, however, he was making more money as a writer than from the university, and he eventually stopped doing research, confining his university role to lecturing students. In 1955, he was promoted to tenured associate professor. In December 1957, Asimov

15004-561: Was pleased to give autographs. He was of medium height, 5 ft 9 in (1.75 m) and stocky build. In his later years, he adopted a signature style of "mutton-chop" sideburns . He took to wearing bolo ties after his wife Janet objected to his clip-on bow ties. He never learned to swim or ride a bicycle, but did learn to drive a car after he moved to Boston. In his humor book Asimov Laughs Again , he describes Boston driving as "anarchy on wheels". Asimov's wide interests included his participation in later years in organizations devoted to

15128-594: Was removed from a task force days before it sailed to participate in Operation Crossroads nuclear weapons tests at Bikini Atoll . He was promoted to corporal on July 11 before receiving an honorable discharge on July 26, 1946. After completing his doctorate and a postdoctoral year with Robert Elderfield , Asimov was offered the position of associate professor of biochemistry at the Boston University School of Medicine . This

15252-473: Was the computer scientist and artificial intelligence expert Marvin Minsky . Asimov was an on-and-off member and honorary vice president of Mensa International , albeit reluctantly; he described some members of that organization as "brain-proud and aggressive about their IQs". After his father died in 1969, Asimov annually contributed to a Judah Asimov Scholarship Fund at Brandeis University . In 2006, he

15376-421: Was the president of the American Humanist Association . Several entities have been named in his honor, including the asteroid (5020) Asimov , a crater on Mars , a Brooklyn elementary school, Honda 's humanoid robot ASIMO , and four literary awards . There are three very simple English words: 'Has', 'him' and 'of'. Put them together like this—'has-him-of'—and say it in the ordinary fashion. Now leave out

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