Navigation Links


Enzyme in Biological Definition

Active site

... The active site of an enzyme is the binding site where catalysis occurs. ... inhibition , the inhibitor binds to the enzyme at another site, the allosteric site , and this causes a structural change in the enzyme such that the active site is rendered useless. ...

Allostery

... In biochemistry , an enzyme or other protein is allosteric if its ... Nemethy, and Filmer. Both postulate that enzyme subunits exist in one of two conformations, ... The concerted model of allostery postulates that enzyme subunits are connected in such a way that a ...

Allostery

... In biochemistry , an enzyme or other protein is allosteric if its ... Nemethy, and Filmer. Both postulate that enzyme subunits exist in one of two conformations, ... The concerted model of allostery postulates that enzyme subunits are connected in such a way that a ...

Apoptosis

... nucleus, is cell suicide triggered by the nuclear enzyme poli(ADP-ribose) polymerase-1, or PARP-1. This enzyme plays a crucial role in maintaining genomic ... and purified interleukin-1-beta converting enzyme (ICE) in human cells, and succeeded in cloning ...

ATPase

... reaction releases energy , which the enzyme (in most cases) harnesses to drive other ... mitochondria and chloroplasts is an anabolic enzyme that harnesses the energy of a transmembrane ... a molecule of adenosine triphosphate (ATP). This enzyme works when a proton moves down the concentration ...

Competitive inhibitor

... acts on the same active site as the normal enzyme substrate . The substrate molecules cannot enter ... In this mode of inhibition, the activity of the enzyme is completely blocked by the inhibitor and ... the concentration of substrate does not restore enzyme activity. The kinetics of these activities is ...

Ion gradient

... used for making and utilizing ion gradients. The enzyme Na+/K+ ATPase use ATP to make a sodium ion ... the environment with the help of the solar driven enzyme bacteriorhodopsin , here it is used for driving the molecular motor enzyme ATP synthase to make the necessary ...

Enzyme

... An enzyme (in Greek en = in and zyme = blend) is a ... much faster than it otherwise would; the enzyme (again, as with any catalyst) remains unaltered ... of it rolling up the hill. Catalysis by an enzyme is analogous to removing a pebble that is ...

Isozyme

... defined them as different variants of the same enzyme having identical functions and present in the same individual . This definition encompasses (1) enzyme variants that are the product of from different ... if the mutations do not immediately prevent the enzyme from functioning, but instead modify either its ...

Lipase

... A Lipase is a water - soluble enzyme that catalyzes the hydrolysis of ester ... human pancreatic lipase (HPL), which is the main enzyme responsible for breaking down fats in the ... lipids. In the example of lysosomal lipase, the enzyme is confined within an organelle called the ...

Michaelis-Menten kinetics

... Michaelis-Menten kinetics describe the rate of enzyme mediated reactions for many enzymes. It is named ... constant. To determine the maximum rate of an enzyme mediated reaction, the substrate concentration ... ( V max ) of the enzyme. In this state, enzyme active sites are saturated with substrate. Note ...

Polymerase chain reaction

... repeated cycles of duplication driven by an enzyme called DNA polymerase . DNA polymerase ... strand. In Mullis's original PCR process, the enzyme was used in vitro (in a controlled environment ... however, DNA-Polymerase was destroyed so that the enzyme had to be replenished after the heating stage of ...

Restriction enzyme

... A restriction enzyme (or restriction endonuclease ) is an enzyme that cuts double-stranded DNA . The enzyme makes two incisions, one through each of the ...

Signal transduction

... Binding of Ca 2+ in the active center of an enzyme One of the best studied interactions of Ca ... NO is made from arginine and oxygen by the enzyme NO synthase , with citrulline as a by-product. ... through activation of its target receptor, the enzyme soluble guanylate cyclase , which when activated, ...

Virus

... the viral RNA is directly copied using an enzyme called RNA replicase . This enzyme then uses that RNA copy as a template to make ... viruses, called the retroviruses , uses the enzyme reverse transcriptase to synthesize a ...

ATP synthase

... An ATP synthase ( EC 3.6.3.14) is a general term for an enzyme that can synthesize adenosine triphosphate (ATP) from adenosine ... synthase is also present in chloroplasts (CF O F 1 -ATP synthase). The enzyme is integrated into thylakoid membrane; the CF 1 -part sticks into ...

Biochemistry

... . Recently biochemistry has focused more specifically on the chemistry of enzyme -mediated reactions, and on the properties of proteins. The biochemistry ... The dawn of biochemistry may have been the discovery of the first enzyme , diastase , in 1833 by Anselme Payen . In 1828 , Friedrich Whler ...

Biophysics

... Zurab Urushadze , authors of the Quantum-Mechanical (Physical) Model of enzyme Catalysis John P. Wikswo , research on biomagnetism References ... R.R., Madumarov A.K., Urushadze Z.D. and Kharkats Yu.I. Theory of enzyme Catalysis.- Molekuliarnaya Biologia (Moscow), 6, 1972, pp. 431-439 (In ...

Cancer

... for cancer-related fatigue, chemotherapy compared with pancreatic enzyme therapy plus specialized diet for the treatment of pancreatic cancer , ... include COX-2 inhibitors (which inhibit a cyclooxygenase enzyme involved in the synthesis of proinflammatory prostaglandins ). ...

Gene therapy

... cell, or the chromosomes of the cell. This process is done by another enzyme carried in the virus called integrase . Now that the genetic material ... of the problems of gene therapy using retroviruses is that the integrase enzyme can insert the genetic material of the virus in any arbitrary position in ...

Immune system

... at certain sequences, and enzymes that protect their own DNA from this enzyme by methylating the same sequence. Therefore, the bacterium's DNA will not be damaged by the first enzyme because of the presence of the second enzyme. However, when a ...

Lac repressor

... The lac repressor is an enzyme which stops the metabolism of lactose in bacteria as long as glucose ... DNA. DNA can be thought of as a highway , with entrances and exits. The enzyme RNA polymerase is like a car . For a specific protein sequence to be ...

Lineweaver-Burke diagram

... ) is a graphical representation of the Lineweaver-Burke equation of enzyme kinetics : where v is the reaction velocity , K m is the ... Lineweaver-Burke plot is useful for rapidly identifying important terms in enzyme kinetics, such as K m and v max . For instance, the y-intercept of such ...

Lysozyme

... Lysozyme 3D structure. Lysozyme is an enzyme ( EC 3.2.1.17 ), commonly referred to as the "body's own antibiotic ". ... neutrophils (PMN) and released to the mucosal secretions. This enzyme functions by attacking peptidoglycan by hydrolyzing the bond that ...

Monoclonal antibody

... Furthermore, one uses only myeloma cells that have lost a specific enzyme ( hypoxanthine-guanine phosphoribosyltransferase , HGPRT) and therefore ... rare, but when one succeeds, then the healthy partner supplies the needed enzyme and the fused cell can survive in HAT medium. This is the trick to detect ...

Neurotransmitter

... Another mechanism for removal of a neurotransmitter is digestion by an enzyme . For example, at cholinergic synapses (where acetylcholine is the neurotransmitter) the enzyme acetylcholinesterase breaks down the acetylcholine. Neuroactive peptides ...

Peroxisome

... as D-amino acid oxidase and urease oxidase . The peroxisome contains the enzyme catalase which converts H 2 O 2 (hydrogen peroxide, a toxic byproduct ... of the enzymes found in a peroxisome are imported from the cytosol . Each enzyme transferred to a peroxisome has a special sequence at one end of the ...

Polysaccharide

... bonded together by beta- linkages. Humans and many other animals lack an enzyme to break the beta- linkages, so they do not digest cellulose. Certain animals can digest cellulose, because bacteria possesing the enzyme are present in their gut. Acidic polysaccharides Acidic ...

Purine

... humans and some animal species (e.g. dogs) that lack an intrinsic urease enzyme that can further degrade uric acid. The deficiency of another enzyme, ... (or from food) can also be salvaged and reused in new nucleotides. The enzyme adenine phosphoribosyltransferase salvages adenine, while ...

Blood type

... alleles : i , A , and B . The gene encodes a glycosyltransferase , an enzyme that modifies the carbohydrate content of the red blood cell ... B antigens. For instance, the B allele must be present to produce the B enzyme that modifies the H antigen to become the B antigen. It is the same for ...

RNA

... of higher-order structures. Synthesis RNA is made by an enzyme , RNA polymerase , using DNA as a template. The synthesis begins when the enzyme binds to special promoter regions on the DNA helix; these regions mark ...

Vesicle

... are a basic tool of the cell for organizing metabolism , transport, enzyme storage, as well as being chemical reaction chambers. Many vesicles are ... The membrane of the lysosome is impermeable for lysozyme , the enzyme that does the actual digestion, to protect the cell interior from being ...

Coenzyme A

... into Acetyl-CoA is referred to as the Pyruvate Dehydrogenase Reaction. It is catalyzed by an enzyme-complex called pyruvate dehydrogenase . The enzyme consists of 60 subunits : 24 pyruvate dehydrogenase, 24 dihydrolipoyl transacetylase , and 12 dihydrolipoyl dehydrogenase (commonly denoted E1, E2, ...

Activation energy

... state). A substance that modifies the transition state to lower the activation energy is termed a catalyst ; a biological catalyst is termed an enzyme . Fig 1. The enthalpy profile of a reaction between two hydrogen peroxide molecules to form water and oxygen. The Transition State ...

Antibiotic

... than discarding the contaminated plate, Fleming noticed a clear zone surrounding the colony of mold . Having previously studied the ability of the enzyme lysozyme to kill bacteria, Fleming realized that the mold was secreting something that stopped bacterial growth. He knew that this substance ...

Sticky end/blunt end

... . Blunt ends may be ligated, but the reaction is significantly slower. These terms are most commonly used to describe the product of a restriction enzyme digestion of DNA. ...

Calvin cycle

... carbon dioxide into organic compounds that can be used by the organism. This set of reactions is also called carbon fixation . The key enzyme of the cycle is called RubisCO . The total sum of reactions in the Calvin cycle is the following: 6 CO 2 + 12 NADPH + 12 H 2 O + 18 ATP ...

Cell division

... , become shorter with each division and eventually can no longer protect the chromosome. Cancer cells, on the other hand, are "immortal." An enzyme called telomerase allows them to continue dividing indefinitely. See also Cell cycle Cell growth External link How ...

Citric acid cycle

... by the condensation of oxaloacetate and acetyl-CoA. Figure 1 : Schematic drawing of the citric acid cycle. Molecule enzyme Reaction type Reactants / Coenzymes Products / Coenzymes I. Citrate 1. Aconitase Dehydration H 2 O ...

Coenzyme

... A coenzyme (a.k.a. a prosthetic group ) is an organic non- protein molecule that is a functional part of an enzyme . Coenzymes are generally defined as cofactors that are organic molecules . Many coenzymes are phosphorylated water -soluble vitamins . ...
Other ContentsbotanybotanybrainbrainbrainbrainbrainbrainbrainbrainbrainbraincapacitationcancercancercancercancercancercancercancercancercancercancercarbohydratecarbohydratecarbohydratecarbohydratecarbohydratecarbohydratecarbohydratecarbohydratecarnivorecarnivorefixationfixationfixationfixationfixationfixationfixationfixationOther TagsFestivalOther Tagscancelled 2cancelled 3license 2license 3license 4license 5definite 2definite 3definite 4definite 5services 2services 3services 4services 5stimulation 2stimulation 3stimulation 4stimulation 5wave 2wave 3