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The Building Blocks of Life; Dehydration Removes Water; Hydrolysis Breaks with Water; Enzymes Aid Both Reactions; When you are thirsty, it is your body's way of telling you to drink some water because you are dehydrated. Just like a dehydration reaction, you. Dehydration synthesis refers to the formation of larger molecules from smaller group as well as the reverse reaction involving the hydrolysis of that bond.
Types of Dehydration Synthesis Dehydration synthesis can be classified based on a number of criteria. They can be grouped based on the nature of the reactants. Some reactants are molecules that have two functional groups, which can react with one another. For instance, amino acids contain an amine group and a carboxylic acid functional group attached to the same carbon atom.
Compare and contrast hydrolysis and dehydration.? | Yahoo Answers
The amine group of one amino acid can react with the acid group of another to form an amide bond and release one molecule of water. The newly formed amino acid dimer again contains one free amine group and one free carboxylic acid group allowing the reaction to proceed with more amino acids. Such bi-functional monomers, therefore, give rise to linear products with the monomers attached to each other end-to-end. Alternatively, the reactants could have multiple functional groups, which can create branched products, such as the formation of glycogen from glucose molecules.
Secondly, dehydration reactions can be classified on the nature of the catalyst. In the example on the formation of symmetrical ethers, the catalyst is a hydrogen ion. But for many reactions, especially within a living organism, the pH, salt concentrations and temperature cannot be altered. In these conditions, the presence of some other catalyst is important for driving a reversible reaction in one direction. Biological catalysts are called enzymes and often derive their name from the nature of the reaction they catalyze.
For instance, enzymes that catalyze the formation of DNA from deoxyribonucleotides through condensation reactions are called DNA polymerases. Proteins are modified with carbohydrate moieties through glycosylases. Occasionally enzymes that catalyze a dehydration reaction are also named based on the nature of the enzyme itself. Ribosomes catalyze the formation of the amide bond also known as the peptide bond between two amino acids. Since the catalytic region within the ribosome is made predominantly of RNA rather than protein, it is also known as an RNA enzyme or ribozyme.Condensation and Hydrolysis (IB Biology)
Alternatively, dehydration reactions can be classified based on the product they produce. In biological systems, most dehydration reactions create polymers.
Therefore, these reactions can be grouped based on whether they create complex carbohydrates from simpler monosaccharides, form fatty acids from acetyl coA or synthesize proteins from amino acids.
Finally, dehydration reactions are also involved in the modification of biological molecules such as nucleosides, proteins and carbohydrates. These modifications include phosphorylation and glycosylation and are important for regulating the properties and functions of biopolymers.
This is particularly crucial in many signaling cascades where protein kinases enzymes that catalyze the phosphorylation of proteins are involved. Examples of Dehydration Synthesis Dehydration reactions are involved in the industrial production of many substances that are used in daily life, such as polyesters.
Polyester fibers are used to weave fabrics, yarns and ropes in addition to having a number of other uses including the making of bottles and insulating tapes.
One common polyester is polyethylene terephthalate PET and gives its name to a class of recyclable bottles. PET is formed by dehydration synthesis from two monomers — ethylene glycol and teraphthalic acid. In biological systems, dehydration synthesis reactions occur in every cell, especially since it is important for the formation of ATP.
Nearly all biopolymers are also derived from this reaction. Formation of Glycosidic Bonds Glycosidic bonds are covalent bonds formed between a carbohydrate and any other molecule. Many of these involve a dehydration reaction.
Dehydration/ Hydrolysis Reactions
When maltose is formed from glucose, there is a glycosidic bond between two glucose molecules with the release of one molecule of water.
Long polymers of glucose can be formed in a similar manner through a series of dehydration reactions to give rise to starch, cellulose or glycogen based on the position of the glycosidic bonds.
Other disaccharides like sucrose and lactose are also formed through dehydration reactions between two monosaccharides. Additionally, glycosidic bonds are also involved when a carbohydrate is modified. Here, a glucose molecule is reacting with methanol to give rise to ethyl glucoside. Triglyceride Formation One of the intermediates of carbohydrate and fat metabolism is acetyl coA, a molecule where a two-carbon acetyl group is attached to coenzyme A.
These fatty acids then form triglycerides, which are an important energy storage molecule. Triglycerides derive their name from the fact that all three hydroxyl groups on glycerol undergo esterification with fatty acids.
Each of the three fatty acids undergoes a dehydration reaction with the alcohol moieties on glycerol to generate one molecule of triglyceride. One of the main reasons why triglycerides are considered a better storage medium than carbohydrates is their high energy density.
They have a larger proportion of carbon atoms that can undergo oxidation and contain fewer oxygen molecules because fatty acids are generated from hydrocarbons. The removal of three water molecules in the process of forming a triglyceride further increases the energy density of the molecule.
In this image, R1, R2 and R3 refer to long chain hydrocarbons, each of which is attached to a carboxylic acid functional group. Hydrolysis Hydrolysis is the reverse of a dehydration reaction because it involves the breaking of a covalent bond through the addition of a molecule of water.
Hydrolysis is catalyzed by a large group of enzymes called hydrolases.
Among the most commonly known hydrolases are digestive enzymes. Digestion begins from the mouth, where salivary amylase breaks down starch molecules. This is why extended chewing of starchy foods gives rise to a sweet taste in the mouth.
The action of salivary amylase generates monosaccharides. This is followed by the action of proteases in the stomach that begin the process of breaking peptide bonds in proteins. Hydrolysis Hydrolysis means separating with the use of water. In Chemistry, Hydrolysis is a chemical reaction with water, in which a macromolecule is separated into smaller molecules.
On the other hand, in Biology, this process involves water to split polymers into monomers. The bottom line is Hydrolysis occurs when water is added to the equation to break it down or separate it.
In our bodies, Hydrolysis is the main process to release energy. When we eat food, it is digested or broken down into substances so the body can absorb it and convert it to energy.
Foods, having complex molecules are broken down into simple molecules. When energy is needed for biosynthesis, ATP is hydrolyzed and stored energy is released for utilization.
Dehydration Synthesis Dehydration means to take away water, and synthesis means to build or create something.
Hence, Dehydration Synthesis is defined as taking away water to build something. This process happens by removing one molecule of —OH hydroxyl group and one molecule of -H to form H2O or water.
This results in covalently joining two monomers small molecules to form a polymer larger molecule. Dehydration Synthesis uses condensation in the process and when this continues for a long period of time, a long and complex chain is formed, just like the ones in polysaccharides.