In the process a water molecule is formed. As additional monomers join via multiple dehydration synthesis reactions, the chain of repeating monomers begins to form a polymer. Different types of monomers can combine in many configurations, giving rise to a diverse group of macromolecules. Three of the four major classes of biological macromolecules complex carbohydrates, nucleic acids, and proteins , are composed of monomers that join together via dehydration synthesis reactions.
Complex carbohydrates are formed from monosaccharides, nucleic acids are formed from mononucleotides, and proteins are formed from amino acids. There is great diversity in the manner by which monomers can combine to form polymers.
For example, glucose monomers are the constituents of starch, glycogen, and cellulose. These three are polysaccharides, classified as carbohydrates, that have formed as a result of multiple dehydration synthesis reactions between glucose monomers.
However, the manner by which glucose monomers join together, specifically locations of the covalent bonds between connected monomers and the orientation stereochemistry of the covalent bonds, results in these three different polysaccharides with varying properties and functions. In nucleic acids and proteins, the location and stereochemistry of the covalent linkages connecting the monomers do not vary from molecule to molecule, but instead the multiple kinds of monomers five different monomers in nucleic acids, A, G, C, T, and U mononucleotides; 21 different amino acids monomers in proteins are combined in a huge variety of sequences.
Each protein or nucleic acid with a different sequence is a different molecule with different properties. Hydrolysis reactions result in the breakdown of polymers into monomers by using a water molecule and an enzymatic catalyst. During these reactions, the polymer is broken into two components. If the components are un-ionized, one part gains a hydrogen atom H- and the other gains a hydroxyl group OH— from a split water molecule.
This is what happens when monosaccharides are released from complex carbohydrates via hydrolysis. Hydrolysis reaction generating un-ionized products. One glucose gets a hydroxyl group at the site of the former covalent bond, the other glucose gets a hydrogen atom. This is the reverse of the dehydration synthesis reaction joining these two monomers. If the components are ionized after the split, one part gains two hydrogen atoms and a positive charge, the other part gains an oxygen atom and a negative charge.
This is what happens when amino acids are released from protein chains via hydrolysis. Hydrolysis reaction generating ionized products. One amino acid gets an oxygen atom and a negative charge, the other amino acid gets two hydrogen atoms and a positive charge.
These reactions are in contrast to dehydration synthesis also known as condensation reactions. In dehydration synthesis reactions, a water molecule is formed as a result of generating a covalent bond between two monomeric components in a larger polymer.
In hydrolysis reactions, a water molecule is consumed as a result of breaking the covalent bond holding together two components of a polymer. In our bodies, food is first hydrolyzed, or broken down, into smaller molecules by catalytic enzymes in the digestive tract. This allows for easy absorption of nutrients by cells in the intestine. Each macromolecule is broken down by a specific enzyme. For instance, carbohydrates are broken down by amylase, sucrase, lactase, or maltase.
Proteins are broken down by the enzymes trypsin, pepsin, peptidase and others. Lipids are broken down by lipases. To further understand this, detailed information regarding the difference between hydrolysis and dehydration synthesis is discussed below. 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 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.
It is also is responsible for storing excess glucose molecules as much as larger polysaccharides like starch and glycogen.
Hydrolysis and Dehydration Synthesis work the same way with proteins, carbohydrates, nucleic acids and lipids. As mentioned earlier, in the process of Hydrolysis — when water is added, it separates the bond between oxygen and hydrogen and reforms into two separate hydroxyls.
If a molecule gains a water molecule and breaks down into parts, this process is called hydrolysis. Breaking of bonds as we all know is a degrading process, and this reaction, therefore, comes under catabolism when applied to biological systems.
Not all bonds can be hydrolyzed. Some frequent examples are hydrolysis of salts of weak acids and weak bases, hydrolysis of esters and amides, and hydrolysis of biomolecules like polysaccharides and proteins. Ester and amide bonds are hydrolyzed in synthetic organic reactions as well as in biological systems.
Hydrolysis is bond breakings process hence a way to release energy. It is the main reaction involved in energy release inside our bodies. The complex molecules we eat as food are broken down to simple molecules by various enzymes and the released energy is stored in ATP; the energy currency of the body. When energy is needed for biosynthesis or active transport of substances through cell membranes, ATP is hydrolyzed, and the stored energy is released.
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