Navigation Links
Hydrolysis


Hydrolysis is a chemical process in which a molecule is cleaved into two parts by the addition of a molecule of water. This is distinct from a hydration reaction, in which water molecules are added to a substance, but no cleavage occurs.

Types

Hydrolysis of an ester link

In a hydrolysis reaction that involves breaking an ester link, one hydrolysis product contains a hydroxyl functional group, while the other contains a carboxylic acid functional group.

The fragment of the parent molecule that was originally a carboxylate gains a hydrogen ion from the additional water molecule. The fragment that was originally an alkyl group collects the remaining hydroxyl group from the water molecule.

Thus the ester is effectively reversed to its component alcohol and carboxylic acid.

Hydrolysing peptide link of amino acids

In other hydrolysis reactions such as hydrolysing the peptide links of amino acids only one of the products, the carboxylic acid product, has a hydroxide group derived from the water. The amine product gains the remaining hydrogen ion.

Hydrolysis can be considered as the opposite of condensation, in which two fragments are joined for each water molecule produced. As hydrolysis is a reversible reaction, condensation and hydrolysis can take place at the same time the position of equilibrium determining the amount of each product.

Irreversibility of hydrolysis under physiological conditions

Under physiological conditions (i.e. in dilute aqueous solution), a hydrolytic cleavage reaction, where the concentration of a metabolic precursor is low (on the order of 10-3 to 10-6 molar), is essentially thermodynamically irreversible. To give an example:

A + H2O → X + Y

Assuming that x is the final concentration of products, and that C is the initial concentration of A, and W = [H2O] = 55.5 molar, then x can be calculated with the equation:

let Kd×W = k

then

For a value of C = 0.001 molar, and k = 1 molar, x/C > 0.999. Less than 0.1% of the original reactant would be present once the reaction is complete.

This theme of physiological irreversibility of hydrolysis is used consistently in metabolic pathways, since many biological processes are driven by the cleavage of anhydrous pyrophosphate bonds.

See also

Hydrolysis


'"/>


(Date:11/4/2014)... Nov. 5, 2014 – University of Utah engineers developed ... help jet fuel produce electricity without needing to ignite ... to power portable electronics, off-grid power and sensors. , ... in the American Chemical Society journal ACS Catalysis ... a chemical reaction between a fuel and an oxygen-rich ...
(Date:11/4/2014)... Think about the way our bodies are assembled during ... that they are supposed to become a nerve or ... the correct place and alignment? Researchers at the University ... In a new study, UM researchers describe the signaling ... neighbors, at the head-trunk region. Their discovery may have ...
(Date:11/4/2014)... HOUSTON – (Nov. 4, 2014) – A majority of ... and that could have serious consequences for the rainforests ... researchers shows the positive impacts lemurs can have on ... impact their disappearance could have on the region,s rich ... rainforest have fruits eaten by lemurs. Lemurs in ...
Breaking Biology News(10 mins):Jet-fueled electricity at room temperature 2The inside story: How the brain and skull stay together 2Gardeners of Madagascar rainforest at risk 2Gardeners of Madagascar rainforest at risk 3
... Alberta researcher has discovered a rare practice by red squirrels ... its heart is also a survival tactic. U ... when he discovered a female had adopted a newborn squirrel ... candidate in evolutionary biology, found a baby red squirrel had ...
... funded by the U.S. economic stimulus program (ARRA) Health ... to advance the use of health information technology (HIT) ... been awarded to leading members of the American Medical ... the last two decades has advocated for informatics as ...
... and Space Sciences More than 2,200 scientists are ... sciences in Foz do Iguau at the 2010 Meeting of ... 8 to 12 August, are planning 377 scientific sessions on ... weather events in the Americas, climate impacts of megacities, greenhouse ...
Cached Biology News:Red squirrels: Altruists or self-serving survivalists? 2AMIA Members Manage HITECH Stimulus Grant Awards 22010 Meeting of the Americas, Brazil: News media registration open 22010 Meeting of the Americas, Brazil: News media registration open 32010 Meeting of the Americas, Brazil: News media registration open 4
Other biology definitionOther Tags