reaction

Zona pellucida

...atozoa , and is required to initiate the acrosome reaction . The zona glycoprotein, ZP3 , is responsible for sperm binding, adhering to proteins on the sperm plasma membrane. There is evidence that ZP3 is then involved in the induction of the acrosome reaction, whereby a spermatozoon releases the conte...

Vesicle

...sport, enzyme storage, as well as being chemical reaction chambers. Many vesicles are made in the Golgi app...er to earlier cisterna . Vesicles can be used as reaction chambers for chemical reactions that could damage the cell if they would occur in the cytosol. For e...

Thomas Malthus

...parson. Malthus's views were largely developed in reaction to the optimistic views of his father and his associates, notably Rousseau and William Godwin . In An Essay on the Principle of Population , published in 1798 , Malthus predicted population would outrun food supply, leading to a decrease in food p...

Splicing (genetics)

...e ; Group 2 : perform the same two-step chemical reaction as the protein-mediated reaction (these are thought to be the evolutionary precursor to the much more common spliceosome). Regard...

Signal transduction

...st a few hormone molecules can induce an enzymatic reaction that affect many substrates. The amplification can occur at several points of the signal pathway. Signal amplification at the transmembrane hormone receptor A receptor that has been activated by a hormone can activate many downstream effector...

Blood type

...ible groups can cause an immunological transfusion reaction , resulting in hemolytic anemia , renal failure ...nd hemolyses the blood of the second child. This reaction doesn't always occur and is less likely to occur if the child carries either the A or B antigen and ...

Redox

...Examples of redox reactions A good example is the reaction between hydrogen and fluorine : H 2 + F 2 → 2HF We can write this overall reaction as two half-reactions: an oxidation reaction: H 2 → 2H + + 2e - and a reduction reaction...

Proton-motive force

... chloroplast , where it is generated by the light reaction of photosynthesis and used to synthesize ATP for use in the fixation of CO 2 . In prokaryotes , it exists across the cellular membrane of the organism....

Proprioception

...judgment of effort and location. Juggling trains reaction time and spatial location. Oliver Sacks once reported the case of a young woman who lost her proprioception due to a viral infection of her spinal cord . At first she was not able to move properly at all. Later she relearned by using her sight ...

Prion

...ture to also become distorted, producing a chain reaction that both propagates the disease and generates new infectious material. Since the original hypothesis was proposed, a gene for the PrP protein has been isolated (the PRNP gene), several mutations that cause the variant shape have been identifie...

Primer

...es, such as DNA sequencing and polymerase chain reaction (PCR), require primers. The primers used for thes...arker for the chain reaction. In polymerase chain reaction (PCR), primers are used to determine the DNA fragment to be amplified by the PCR process. The length...

Primary nutritional groups

...cceptors for chemotrophs is limited to those whose reaction is exergonic enough to conserve enough energy for the transition of at least one proton over a membrane (equals to -15 to -20 kJ/mol). In contrast, phototrophs may use any electron donor and can even catalyse highly endergonic reactions (e. g. the ...

Photosystem

...or. Structure A photosystem is made up of a reaction center pigment of chlorophyll a and numerous ant...elengths and pass along their gained energy to the reaction center chlorophyll. When the energy reaches the chlorophyll a, it releases two electrons into an ...

Photosystem

...or. Structure A photosystem is made up of a reaction center pigment of chlorophyll a and numerous ant...elengths and pass along their gained energy to the reaction center chlorophyll. When the energy reaches the chlorophyll a, it releases two electrons into an ...

Photorespiration

...the leaf ) are closed to prevent water loss. The reaction is: RuBP + rubisco + O 2 → phosphoglycolate The glycolate is then sent to peroxisomes . Photorespiration is a wasteful process because no PGAL is created. PGAL is used to create nearly all of the food and structures in the plant. Plan...

Photosynthesis

...ll. In photosystem II, they are used to drive the reaction NADP + + H + + 2e − → NADPH Th...lso to the incorporation of water. Thus the basic reaction by which photosynthesis is used to produce food (such as glucose) was outlined. Modern scientists b...

Light-dependent reaction

...he photosynthetic system is the light-dependent reaction , which converts solar energy into chemical energy... molecule is split in the process; it is the light reaction which produces waste oxygen. The light reaction also generates ATP by powering the addition of a ...

Photolysis

Photolysis refers to any chemical reaction in which a compound is broken down by light . Photolysis is a part of photosynthesis , which occurs in the granum of the chloroplast . In photolysis the light absorbed by the chlorophyll is turned into chemical energy which is used to spl...

Peptide bond

...tween amino acids . Dehydration synthesis reaction The resulting C-N bond is called a peptide bond, and the resulting molecule is called an amide . Polypeptides and proteins are chains of amino acids held together by peptide bonds. The backbone of PNA is also held together by peptide bonds....

Pentose phosphate pathway

...phosphate into ribose 5-phosphate. The overall reaction for this process is: Glucose 6-phosphate + 2 NADPH...ate into 6-phosphoglucono-δ-lactone . This reaction is catalyzed by glucose 6-phosphate dehydrogenase . The hydroxyl group located on carbon 1 of gluco...

Polymerase chain reaction

...mical environment for the DNA-Polymerase The PCR reaction is carried out in a thermal cycler . This is a machine that heats and cools the reaction tubes within it to the precise temperature required for each step of the reaction. To prevent evapor...

Oxidative phosphorylation

...e ATP synthase, generating ATP in the process. The reaction is: ADP 3- + H + + P i ↔ ATP 4- + H 2 O Each NADH molecule contributes enough proton motive force to generate 3 ATP. Each FADH 2 molecule is worth 2 ATP. All together, the 10 NADH and 2 FADH 2 molecules contributed through oxidat...

Redox

...Examples of redox reactions A good example is the reaction between hydrogen and fluorine : H 2 + F 2 → 2HF We can write this overall reaction as two half-reactions: an oxidation reaction: H 2 → 2H + + 2e - and a reduction reaction...

Nutrition

... brought the "diseases of civilisation" with it. A reaction to this has been the development of a slow food trend. This has now got its own University, at the University of Pollenzo in Piedmont Italy whose goal is to promote awareness of good food and health through nutrition. Nutrition research has ident...

Molecular biology

... 2.1 Expression cloning 2.2 Polymerase chain reaction (PCR) 2.3 Gel electrophoresis 2.4 Western blot...st the protein can be studied. Polymerase chain reaction (PCR) Main article: Polymerase chain reaction The polymerase chain reaction is an extremely ...

Michaelis-Menten kinetics

...ature, etc) are at optimal values. Diagram of reaction speed and Michaelis-Menten constant. The speed ...y the substrate concentration at which the rate of reaction is half its maximum. This substrate concentration is called the Michaelis-Menten constant ( K M )...

Metabolism

... function. Photosynthesis Light-dependent reaction (light reaction) Light-independent reaction (dark reaction) Calvin cycle Carbon fixation Drug metabolism Drug metabo...

Lineweaver-Burke diagram

...ation of enzyme kinetics : where v is the reaction velocity , K m is the Michaelis-Menten constant , v max is the maximum reaction velocity, and [ S ] is the substrate concentration . The Lineweaver-Burke plot is useful for rapid...

Light-dependent reaction

...he photosynthetic system is the light-dependent reaction , which converts solar energy into chemical energy... molecule is split in the process; it is the light reaction which produces waste oxygen. The light reaction also generates ATP by powering the addition of a ...

Kary Mullis

... In the 1980s , he invented the polymerase chain reaction (PCR), a central technique in molecular biology which allows the amplification of specified DNA sequences. He was awarded the Nobel Prize in Chemistry and the Japan Prize for this work in 1993 . Mullis was born in North Carolina, and grew ...

Isozyme

...that can catalyse a slightly different chemical reaction , in which case the mutation may cause an increase in fitness , and be favoured by natural selection . An example of an isozyme An example of an isozyme is glucokinase , a variant of hexokinase which is not inhibited by glucose 6-phosphate ...

Insulin

... was so impure that he suffered a severe allergic reaction and further injections were cancelled. Over the n...or widespread clinical use, much reducing impurity reaction problems. Eli Lilly marketed the first such synthetic insulin, Humulin, in 1982 . Genentech Inc dev...

Hydrolytic enzyme

...ng the two monomers. The reverse of a hydrolysis reaction is a condensation reaction ....

Hydrolysis

...ule of water . This is distinct from a hydration reaction , in which water molecules are added to a substanc...es Hydrolysis of an ester link In a hydrolysis reaction that involves breaking an ester link, one hydrolysis product contains a hydroxyl functional gro...

Homeostasis

...h the system reacts: Negative feedback is a reaction in which the system responds in such a way as to reverse the direction of change. Since this tends to keep things constant, it allows the maintenance of homeostasis. For instance, when the concentration of carbon dioxide in the human body increas...

Photosynthesis

...ll. In photosystem II, they are used to drive the reaction NADP + + H + + 2e − → NADPH Th...lso to the incorporation of water. Thus the basic reaction by which photosynthesis is used to produce food (such as glucose) was outlined. Modern scientists b...

Glycolysis

... in the form of the coenzyme NADH . The global reaction of glycolysis is: Glucose + 2 NAD + + 2 ADP + 2...es than the hexokinases in most other cells). This reaction consumes 1 ATP molecule, but the energy is well spent: although the cell membrane is permeable t...

Glucose

... react with the amino groups of proteins . This reaction ( glycosylation ) reduces or destroys the function of many enzymes . The low rate of glycosylation is due to glucose's preference for the less reactive cyclic isomer . Nevertheless, many of the long-term complications of diabetes (e.g., blindness...

Genetics

...Kary Banks Mullis discovers the polymerase chain reaction enabling the easy amplification of DNA 1989 The first human gene is sequenced by Francis Collins and Lap-Chee Tsui , it encodes the CFTR protein, defects in this gene cause cystic fibrosis 1995 The genome of Haemophilus influenzae ...

Genetic fingerprinting

...ts in criminal cases, is that of polymerase chain reaction (PCR). PCR involves the amplification of specific regions of DNA that are known to be highly variable from one individual to another. This amplification process allows the scientist to start with a very small amount of material, and the outcome is a...

Free energy

...stems at constant temperature, undergoing chemical reaction in closed containers (at constant volume) or in open containers (at constant pressure). In the first case one would use the Helmholtz free energy as a measure of available work, and in the second one would use the Gibbs free energy . Physicist...

Exergonic reaction

An exergonic reaction is a chemical reaction where the variation of free energy is negative. This tells us the direction that the reaction will...

Equilibrium

...mical equilibrium , the state in which a chemical reaction proceeds at the same rate as its reverse reaction, resulting in no net change in the amount of each compound . Mechanical equilibrium , also known as static equilibrium , the state of a body at rest or in uniform motion in which the sum of al...

Enzyme

...or protein complex , that catalyzes a chemical reaction and also controls the 3D orientation of the catal...ctivation energy of a reaction, thus allowing the reaction to proceed to its steady state or completion much faster than it otherwise would; the enzyme (again,...

Endergonic reaction

Exergonic An endergonic reaction is a chemical reaction in which the change in free energy is positive. An endergonic reaction is a reaction in which &Del...

Diabetes mellitus

...duction. The autoimmune attack may be triggered by reaction to an infection, for example by one of the viruses... if less food is consumed causing a hypoglycemic reaction if not intelligently adjusted. In addition, exercise decreases insulin requirements as exercise incr...

Cryptozoology

... showTocToggle("show","hide") 1 Mainstream reaction 2 Notable topics of interest in cryptozoology ... 5 Sources 6 External links Mainstream reaction While many cryptozoologists strive for legitimacy and many are respected scientists in other fields...

Ion gradient

...ne of several ways a thermodynamically unfavorable reaction can be driven by a thermodynamically favorable one, I.E by letting the ions diffuse through the high concentration side to the low concentration side through transmembrane proteins which can use them as energy. Several different types of ion gradient...

Cloning

...t about 65 years previous, using polymerase chain reaction (PCR) [3] . However, on February 15 2005 the museum announced that it was stopping the project after tests showed the specimens' DNA had been too badly degraded by the ( ethanol ) preservative. One of the continuing obstacles in the attempt to...

Chromatography

...cal reactions and for the qualitative analysis of reaction products. TLC plates are made by mixing the adsorbent with a small amount of inert binder like calcium sulfate (gypsum) and water, spreading the a thick slurry on the carrier, drying the plate, and activation of the adsorbent by heating in an ov...

Chromosome

... cells can be locked in metaphase in vitro (in a reaction vial) with colchicine . These cells are then stained (the name chromosome was given because of their ability to be stained), photographed and arranged into a karyotype (an ordered set of chromosomes, Fig. 3), also called karyogram . Like many sex...

Chloroplast

... the thylakoid space or lumen. The photosynthesis reaction takes place on the surface of the thylakoid. The photosynthetic proteins in the membrane bind chlorophyll , which is present with various accessory pigments . These give chloroplasts their green colour. Algal chloroplasts may be golden, brown,...

Charles Darwin

...igin of man and his history" . Reaction See reaction to Darwin's theory for details. Reviewers were ...n's theory publication of Darwin's theory reaction to Darwin's theory External links AboutDarwin.com The Friends of Charles Darwin Dar...

Cell metabolism

...re about mitochondria to find out more about the reaction and how its energy is secured in ATP . Fat catabolism Main article: Fat catabolism Fat catabolism, also known as lipid catabolism, is the process of lipids or phospholipids being broken down by lipases . The opposite of fat catabolism is ...

Cellular respiration

...;in a bonfire, for example—is an exothermic reaction that releases a large amount of energy rather qui...lace in the cytoplasm of the cell . The overall reaction can be expressed this way: Glucose + 2 NAD + + 2 ADP + 2 P i → 2 NADH + 2 pyruvate + 2 ATP...

Capacitation

...nt when consulting sources. See also cortical reaction Acrosome reaction Reference Beaudin, Stacey; Kipta, Donna; and Orr, Annamarie. (October 9, 1996). Current res...

Sticky end/blunt end

... DNA ligase . 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....

ATPase

... free phosphate ion . This dephosphorylation reaction releases energy , which the enzyme (in most cases) harnesses to drive other chemical reactions that would not otherwise occur. This process is widely used in all known forms of life . Some such enzymes are integral membrane proteins (anchored...

ATP synthase

...ate by utilizing some form of energy. The overall reaction sequence is: ADP + P i → ATP ATP synthase in E. coli These enzymes are of crucial importance in almost all organisms, because ATP is the common "energy currency" of cells. In mitochondria , the F O F 1 ATP synthase has a...

Artificial life

...n insects reacted. They then compared that to the reaction of real termites to identical changes in laboratory colonies, and refined their theories about the rules which underlay the behavior. James Doyne Farmer was a key figure in tying artificial life research to the emerging field of complex adaptive s...