Biochemistry
In 1833, Anselme Payen isolated the first enzyme known as diastase. This discovery marked a turning point in how scientists viewed living matter. Before this moment, many believed life possessed an invisible vital force that chemistry could not explain. Friedrich Wöhler challenged that idea in 1828 when he synthesized urea from potassium cyanate and ammonium sulfate. His work suggested organic molecules could exist without a biological source. The term biochemistry itself appeared later when Vinzenz Kletzinsky published his Compendium der Biochemie in Vienna during 1858. Felix Hoppe-Seyler used the phrase again in 1877 to describe physiological chemistry within the journal Zeitschrift für Physiologische Chemie. Carl Neuberg is often credited with coining the modern word in 1903. Eduard Buchner demonstrated alcoholic fermentation in cell-free extracts in 1897. That experiment proved complex biochemical processes could occur outside living cells. Emil Fischer studied protein chemistry while F. Gowland Hopkins explored enzymes and dynamic biochemical systems. These pioneers laid the foundation for understanding life through chemical reactions rather than mystical forces.
Six elements make up nearly 99% of human body mass including carbon hydrogen nitrogen oxygen calcium and phosphorus. Most organisms share these elemental needs though plants require boron and silicon differently than animals. Four main classes of biomolecules form the structural basis of all life: carbohydrates lipids proteins and nucleic acids. Carbohydrates like glucose store energy and provide structure through monosaccharide units linked by glycosidic bonds. Glucose has the formula C6H12O6 while fructose shares that same composition but tastes sweet. Disaccharides such as sucrose combine two monosaccharides releasing water during dehydration synthesis. Lipids include fatty acids triglycerides and phospholipids which form cell membranes due to their amphiphilic nature. Proteins consist of amino acid chains where twenty standard types create diverse three-dimensional shapes. Hemoglobin contains 146 amino acid residues with four subunits working together to transport oxygen. Nucleic acids like DNA and RNA carry genetic information using nitrogenous bases adenine cytosine guanine thymine and uracil. Adenine binds with thymine or uracil via two hydrogen bonds while cytosine pairs with guanine using three bonds.
Glycolysis breaks down one molecule of glucose into two molecules of pyruvate producing net ATP gain. This ten-step pathway does not require oxygen and converts NAD+ to NADH reducing equivalents. When oxygen becomes available pyruvate enters the citric acid cycle generating additional ATP molecules. Aerobic cells convert pyruvate to acetyl-CoA releasing carbon dioxide as waste. The electron transport system transfers electrons ultimately to oxygen forming water. Humans breathe in oxygen and exhale carbon dioxide through this process. Skeletal muscles shift to anaerobic metabolism during vigorous exercise converting glucose to lactate. The Cori cycle describes how lactate crosses the bloodstream to the liver for gluconeogenesis. Gluconeogenesis regenerates glucose from noncarbohydrate sources when glycogen stores deplete. Vertebrates use this pathway during starvation or endocrine disorders requiring three times more energy than glycolysis produces. Yeast converts pyruvate to ethanol plus carbon dioxide when no oxygen exists. Complex life appeared only after Earth accumulated large amounts of oxygen enabling efficient energy extraction.
James D Watson Francis Crick Rosalind Franklin and Maurice Wilkins solved DNA structure in the 1950s. Their work revealed how genetic information transfers within cells through molecular mechanisms. George Beadle and Edward Tatum received the Nobel Prize in 1958 showing one gene produces one enzyme using fungi research. Colin Pitchfork became the first person convicted of murder with DNA evidence in 1988 advancing forensic science. Andrew Z Fire and Craig C Mello won the 2006 Nobel Prize discovering RNA interference silencing gene expression. Nucleotides form nucleic acids containing a pentose sugar phosphate group and nitrogenous base. Adenine cytosine guanine occur in both RNA and DNA while thymine appears only in DNA. Uracil replaces thymine in RNA molecules. The central dogma describes genetic material transcribed into RNA then translated into protein despite emerging novel roles for RNA. Scientists use sequence-comparison methods to identify homologies between related proteins determining evolutionary patterns. Mutants lacking functional components help researchers understand wild type phenotypes through knockout studies.
Chromatography X-ray diffraction dual polarisation interferometry NMR spectroscopy radioisotopic labeling electron microscopy and molecular dynamics simulations advanced biochemistry since the mid-20th century. These techniques allowed detailed analysis of metabolic pathways like glycolysis and the Krebs cycle. Researchers combined biochemical methods with genetics molecular biology and biophysics creating interdisciplinary approaches. The Protein Data Bank contains examples showing diverse protein structures from isomerase domains. Sequence alignments and structural alignments identify homologies helping scientists determine function from structure. Antibodies attach to specific molecules enabling sensitive tests like enzyme-linked immunosorbent assay ELISA used in modern medicine. Phospholipids serve as co-solubilizers or drug carrier components in pharmaceutical products including liposomes. Empty viral capsids deliver gene therapy or drug molecules as chemical hybrids between biomolecules and synthetic devices. SystemsX.ch represents a Swiss initiative focusing on systems biology integrating multiple biological scales.
Biochemical research drives advancements in disease treatment nutrition science and crop improvement. Biochemists investigate causes and cures of diseases using findings applied primarily in medicine. Nutrition studies maintain health while addressing effects of nutritional deficiencies documented by UNICEF in 2010. Agricultural biochemists examine soil and fertilizers improving crop cultivation storage and pest control. Humans synthesize only half of twenty amino acids requiring ingestion of isoleucine leucine lysine methionine phenylalanine threonine tryptophan and valine. Mammals produce alanine asparagine aspartate cysteine glutamate glutamine glycine proline serine and tyrosine without dietary intake. Free ammonia exists as ammonium ion in blood proving toxic so mammals convert it into urea via the urea cycle. Unicellular organisms release ammonia directly into environments while bony fish dilute it in water. Vegetable oils rich in polyunsaturated fatty acids undergo digestion breaking into fatty acids and glycerol. Lipid-containing foods like butter cheese and ghee provide essential nutrients for daily life.
Common questions
When did Anselme Payen isolate the first enzyme known as diastase?
Anselme Payen isolated the first enzyme known as diastase in 1833. This discovery marked a turning point in how scientists viewed living matter by challenging the belief that life possessed an invisible vital force.
Who coined the modern word biochemistry and when was it established?
Carl Neuberg is often credited with coining the modern word biochemistry in 1903. The term itself appeared earlier when Vinzenz Kletzinsky published his Compendium der Biochemie in Vienna during 1858.
What six elements make up nearly 99% of human body mass?
Six elements make up nearly 99% of human body mass including carbon hydrogen nitrogen oxygen calcium and phosphorus. Most organisms share these elemental needs though plants require boron and silicon differently than animals.
How does glycolysis break down glucose into pyruvate?
Glycolysis breaks down one molecule of glucose into two molecules of pyruvate producing net ATP gain through a ten-step pathway. This process does not require oxygen and converts NAD+ to NADH reducing equivalents.
When did James D Watson Francis Crick Rosalind Franklin and Maurice Wilkins solve DNA structure?
James D Watson Francis Crick Rosalind Franklin and Maurice Wilkins solved DNA structure in the 1950s. Their work revealed how genetic information transfers within cells through molecular mechanisms.