A hydrogen bond is formed by a dipole-dipole force between an electronegative atom (the hydrogen acceptor) and a hydrogen atom that attaches covalently with another electronegative atom (the hydrogen donor) of the same molecule or of a different molecule. Only nitrogen, oxygen, and fluorine atoms can interact with hydrogen to form a hydrogen bond donor; this is different than a hydrogen covalent bond. The hydrogen bond acceptor however can be any atom which is in a polar bond, is electronegative, and has a lone pair. In a hydrogen bond, the lone pair electrons on oxygen, nitrogen, or fluorine interact with the partial positive hydrogen that is covalently bonded to one of those atoms. The hydrogen atom in a hydrogen bond is shared by two electronegative atoms such as oxygen or nitrogen.) Hydrogen bonds are responsible for specific base-pair formation in the DNA double helix and a major factor to the stability of the DNA double helix structure. A hydrogen-bond donor includes the hydrogen atom and the atom to which it is most tightly linked with. The hydrogen-bond also play a very important roles in proteins' structure because it stabalizes the secondary, tertiary and quaternary structure of proteins which formed by alpha helix, beta sheets, turns and loops. The hydrogen-bond connected the amino acides between different polypeptide chains in proteins structure. The hydrogen-bond acceptor is the atom that is less tightly linked to the hydrogen atom.
Hydrogen bonds are fundamentally electrostatic interactions and are much weaker than covalent bonds. They are, however, the strongest kind of dipole-dipole interaction. The electronegative atom to which the hydrogen atom is bonded with pulls electron density away from the hydrogen atom, developing a partial positive charge. Therefore, the hydrogen atom can then interact with a partial negatively charged atom through an electrostatic interaction.
Hydrogen bond with ammonia
- 1 Components
- 2 H-bonding
- 3 Properties of Water Due to Hydrogen Bonding
- 4 Hydrogen bond and physical properties
- 5 Hydrogen bond in proteins
- 6 Hydrogen bonding in water
- 7 Hydrogen bonding in DNA
- 8 References
Components[edit | edit source]
Hydrogen bonding is a form of electrostatic interaction between a hydrogen atom bonded to two electronegative atoms; one of which is the hydrogen-bond donor that has a stronger bond between itself and the hydrogen. These electronegative atoms are nitrogen, oxygen, and fluorine; this electronegative atom pulls electron density away from the hydrogen atom, giving it a partially positive charge. This partial positive charge is attracted to the partial negative charge of the hydrogen bond acceptor (an electron density rich atom). The chemical bond formed between the hydrogen-bond donor, hydrogen atom, and hydrogen-bond acceptor has a straight, linear structure.
H-bonding[edit | edit source]
Hydrogen bonding (H-bond) is a non-covalent type of bonding between molecules or within them, intermolecularly or intramolecularly. This type of bonding is much weaker and much longer than the covalent bond and ionic bonds, but it is stronger than a van der waals interaction. It also carries some features of covalent bonding: direct and straight. In other words, H-bond donor and H-bond acceptor lie along the straight line. In order to form an H-bond, an H-bond donor and H-bond acceptor are required. The H-bond donor is the molecule that has a hydrogen atom bonded to a highly electronegative, small atom with available valence (N, F, and O follow the above description the best because they are very electronegative, making H, which is covalently attached to them, very positive). The H-O, H-N, and H-F bonds are extremely polar; as a result, the electron density is easily withdrawn from the hydrogen atom towards the electronegative atom. The partially positive hydrogen in one molecule attracts to partially negative lone pair of the electronegative atom on the other molecule and H-bond forms as a result of such an interaction. All the hydrogen bonds vary in strength
Other important facts about hydrogen bonding are as follows. The small sizes of nitrogen, oxygen, and fluorine are essential to H bonding for two reasons. One is that it makes those atoms electronegative that their covalently bonded H is highly positive. Other reason is that it allows the lone pair on the other oxygen, nitrogen, or fluorine to come close to the H. Also, hydrogen bonding has a profound impact in many systems. Hydrogen bonding is also involves in the action of many enzymes [The Molecular Nature of Matter and Change].
Properties of Water Due to Hydrogen Bonding[edit | edit source]
Ammonia, water, and hydrogen fluoride all have higher boiling points than other similar molecules, which is due to hydrogen bonds. Bonds between hydrogen and these strongly electronegative atoms are very polar, with a partial positive charge on hydrogen. This partially positive hydrogen is strongly attracted to the partially negative oxygen on the adjacent molecule. In general, boiling points rise with the increase molecular weight, both because the additional mass requires higher temperature for rapid movement of the molecules and because heavier molecules have a greater London forces. Water's freezing point is also much higher than other similar molecules. An unusual feature is that it decreases in density when it freezes. The tetrahedral structure around each oxygen atom, with two regular bonds to hydrogen and two to other molecules. This requires a great amount of space between the ice molecules. Clathrates are molecules trapped in holes of solid, like ice, that is theorized to be able to be used as anesthesia.
Hydrogen bond and physical properties[edit | edit source]
Hydrogen bonding has a significant influence on a molecule's boiling points. The boiling point usually increases with the increase of the molar mass. However, molecules that are involved in intermolecular H-bonding bonding have much higher boiling points in comparison with the molecules of the same molar mass that are not involved in H-bonding. This is because the unusually strong H-bonding forces allow for stronger interaction between water molecules and therefore creating a stronger bond and higher boiling point.  In addition, H-bonding is responsible for many unusual proprieties of water, such as its high boiling point, melting point, heat of vaporization, high dielectric constant, surface tension, capillary action etc.
Hydrogen bonding can occur between hydrogen and four other elements. Oxygen(most common), Fluorine, Nitrogen and Carbon. Carbon is the special case in that it only really interacts in hydrogen bonding when it is bound to very electronegative elements such as Fluorine and Chlorine. 
Hydrogen bonding is an important component of the three major macromolecules in biochemistry such as proteins, nucleic acids, and carbohydrates. The H-bonding is responsible for the structure and properties of proteins(enzymes). Hydrogen bonding is applicable in these biomolecules because of functional groups present. Some such are the carboxylic acid, alcohol or even amine groups. These provide either an hydrogen, oxygen or nitrogen for possible hydrogen bonds.
Hydrogen bond in proteins[edit | edit source]
Hydrogen bonding within the "green fluorescent protein" 1RRX.
As previously mentioned, hydrogen bond can be intermolecular (ex. the bonding of water molecules) as well as intramolecular (ex. the bonding of protein and DNA). The secondary structure of protein forms as a result of H-bonding between amino acids. For example, an α-helix is a rod-like secondary structure that forms as a result of H-bonding between the carboxyl group of (i) amino acid to the amino group of (i+4) amino acid. The turn (loop family) is a secondary structure which forms as a result of H-bond between carboxyl group of (i) amino acid and amino group of (i+3) amino acid. The β-sheet is a secondary structure which forms as a result of H-bonding between two or more β-strands. An anti-parallel β-strands forms hydrogen bonds that are straight due to the carbonyl group and the amino group being directly aligned, while a parallel β-strand forms hydrogen bonds that are slightly weaker in comparison to the anti-parallel because the carbonyl group and the amino group don't align perfectly, which forms a longer and weaker hydrogen bond.
The solubility of proteins in water is dependent on the ability to form hydrogen bonds with the protein surface. Proteins that have a greater hydrophilic surface content are generally more capable of forming hydrogen bonds with the surrounding water. The alteration of salt concentration of the solution, as is performed in salting out/in, creates a shielding effect that reduces the ability to form an H-bond with the hydrogens in water. The protein precipitation method of salting out utilizes this concept in protein fractionation.
Hydrogen bonding in water[edit | edit source]
Hydrogen bonding in water
The simplest example of a hydrogen bond can be found in water molecules. A water molecule consists of one oxygen atom attached to two hydrogen atoms. A hydrogen bond can be formed between two molecules of water. In the case of liquid water where there are many water molecules present, each water molecule could potentially hydrogen bond with up to 4 other molecules (2 through its 2 hydrogen atoms with each hydrogen bonding to another oxygen and another 2 through its 2 lone pairs on the oxygen that can hydrogen bond to 2 other hydrogen atoms).
Although water has a low molecular mass, it has an unusually high boiling point. This property can be attributed to the large number of hydrogen bonds that exist within the water. Since these bonds are difficult to break, water’s melting point, viscosity, and boiling point are relatively high in comparison to other liquids that are similar but lack the hydrogen bonding. Water contains substantially more hydrogen bonds (up to 4) relative to certain other liquids that also have hydrogen bonding. An example would be ammonia in which the nitrogen only has one lone pair but 3 hydrogen atoms and thus only capable of forming up to 2 hydrogen bonds.
Hydrogen bonding can also explain why the density of ice is less than the density of liquid water. In water's liquid form, the hydrogen bonding that keeps the molecules close together is constantly being broken and remade repeatedly at room temperature. But as the water turns into ice, the hydrogen bonding causes the water molecules to form a rigid, lattice structure, which causes large gaps between the molecules, resulting in it's smaller density yet larger volume.
Hydrogen bonding also accounts for water's high surface tension. The large availability of hydrogen bonding between water molecules (4 hydrogen bonds to one water molecule) proves how well they can stick to each other, forming a strong and stretchy surface. Common examples from which this characteristic can be observed include a cup filled slightly over the top without spilling over, or small organisms that are able to stay on top of the water without breaking its surface.
Water has a different number of hydrogen bonds depending upon the temperature. It is estimated that at 0oC each water molecule has an average of 3.69 hydrogen bonds, while at 25oC it has an average of 3.59 hydrogen bonds, and at 100oC it has an average of 3.24 bonds. The decreasing hydrogen bonds with an increase in temperature can be attributed due to the increase of molecular motion.
Hydrogen bonding in DNA[edit | edit source]
DNA contains four bases: Guanine, Cytosine, Adenine, and Thymine. The complementary base pairs of guanine with cytosine and adenine with thymine connect to one another using hydrogen bonds. These hydrogen bonds between complementary nucleotides are what keeps the two strands of a DNA helix together. Each base can also form hydrogen bonds with the external environment such as with water. Although these internal and external hydrogen bonds are fairly weak, the consolidated power of all the millions of hydrogen bonds in DNA make it a stable molecule. Also, the hydrogen bonds on the phosphate groups on each nucleotide interact inducing two strands of DNA to conform to a helical structure.
The base pairing in the DNA (one purine and one pyrimidine base) can be explained in more details. In addition to holding the DNA strands together, the hydrogen bonding between the complementary bases also sequester the bases in the interior of the double helix. Therefore, the hydrogen bonding between the bases reinforces the hydrophobic effects that stabilize the DNA. The hydrophobic bases are again kept in the inside of the helix, whereas the polar exterior is touching the solvent water. The hydrogen bonding is a weak molecular force, but it is an additive effect that stabilizes the DNA molecule. The bases are precisely held by hydrogen bonding with the energy of 1 to 5 kcal/ mol (4 to 21 kJ/mol).
The hydrogen bonding in the DNA bases of one purine (guanine and adenine) and one pyrimidine (cytosine and thymine) creates a similar shape. The pairing of guanine and cytosine shape and structure is very similar to that of the pairing of adenine and thymine. Cytosine and Guanine are held together by three hydrogen bonds. The pairing of adenine and thymine share two hydrogen bonds, thus the bond is slightly weaker and slightly longer.
G-C hydrogen bonding
A-T hydrogen bonding
References[edit | edit source]
Silberberg, Martin S. Chemistry "The Molecular Nature of Matter and Change." Fifth Edition. 2009.
- ↑ a b c hydrogen bonding, October 28, 2012
What is hydrogen bond PDF? ›
DEFINITION. The hydrogen bond is an attractive interaction between a hydrogen atom from a molecule or a. molecular fragment X–H in which X is more electronegative than H, and an atom or a group of. atoms in the same or a different molecule, in which there is evidence of bond formation.What is hydrogen bond in biochemistry? ›
hydrogen bonding, interaction involving a hydrogen atom located between a pair of other atoms having a high affinity for electrons; such a bond is weaker than an ionic bond or covalent bond but stronger than van der Waals forces.Why is an understanding of hydrogen bonding essential to the study of biochemistry? ›
Hydrogen bonds are extremely important in biology, as they are the reason for the structure of DNA and its properties. These bonds are responsible for the connections between the two strands of DNA between the nucleotide base pairs.What are three types of noncovalent bonds? ›
There are three principle kinds of noncovalent forces: ionic interactions. hydrophobic interactions. hydrogen bonds.Which is the strongest hydrogen bond? ›
Fluorine because of its smaller size and highest electronegativity shows strongest hydrogen bonding.Why hydrogen bond is important in our life? ›
Hydrogen bonds provide many of the critical, life-sustaining properties of water and also stabilize the structures of proteins and DNA, the building block of cells.What are the 3 types of hydrogen bonds? ›
Usually three classes are distinguished: weak, moderate, and strong bonds, with energetic boundaries at about 2 and 15 kcal/mol. The weak hydrogen bonds involve less polar X-H groups in proton donors, like C-H or P-H groups, or less polar acceptors, like the N2 molecule in the N2⋯HF complex discussed above.What is a hydrogen bond called? ›
A hydrogen bond is an intermolecular force (IMF) that forms a special type of dipole-dipole attraction when a hydrogen atom bonded to a strongly electronegative atom exists in the vicinity of another electronegative atom with a lone pair of electrons. Intermolecular forces (IMFs) occur between molecules.Is DNA a hydrogen bond? ›
Each DNA molecule consists of two nucleotide chains wrapped around each other in a double helix and held together by hydrogen bonds. This hydrogen bonding involves only the nitrogenous bases.Why is hydrogen bond important in DNA? ›
Hydrogen bonds are responsible for specific base-pair formation in the DNA double helix and a major factor to the stability of the DNA double helix structure. A hydrogen-bond donor includes the hydrogen atom and the atom to which it is most tightly linked with.
What are the applications of hydrogen bond? ›
Hydrogen bonding is an important factor in determining the 3D structures and properties that are acquired by synthetic and natural proteins. Hydrogen bonds also play an important role in defining the structure of cellulose as well as derived polymers such as cotton or flax.Why is chemical bond so important? ›
Chemical bonding is one of the most basic fundamentals of chemistry that explains other concepts such as molecules and reactions. Without it, scientists wouldn't be able to explain why atoms are attracted to each other or how products are formed after a chemical reaction has taken place.What are the 4 types of bonds and describe them? ›
There are four types of chemical bonds essential for life to exist: Ionic Bonds, Covalent Bonds, Hydrogen Bonds, and van der Waals interactions. We need all of these different kinds of bonds to play various roles in biochemical interactions. These bonds vary in their strengths.What are the 4 types bonds? ›
Four main bonding types are discussed here: ionic, covalent, metallic, and molecular.Is water polar or nonpolar? ›
Water is a Polar Covalent Molecule
The unequal sharing of electrons between the atoms and the unsymmetrical shape of the molecule means that a water molecule has two poles - a positive charge on the hydrogen pole (side) and a negative charge on the oxygen pole (side).
Hydrogen bonds are weak, relative to covalent bonds. The energy required to break the O—H covalent bond (the bond dissociation energy) is about 111 kcal/mole, or in more proper SI units, 464 kJ/mole.How do hydrogen bonds affect proteins? ›
Hydrogen bonds provide most of the directional interactions that underpin protein folding, protein structure and molecular recognition. The core of most protein structures is composed of secondary structures such as α helix and β sheet.What makes a bond strong or weak? ›
The strength of a bond between two atoms increases as the number of electron pairs in the bond increases. Thus, we find that triple bonds are stronger and shorter than double bonds between the same two atoms; likewise, double bonds are stronger and shorter than single bonds between the same two atoms.Where are hydrogen bonds found in the body? ›
Hydrogen bonds occur in inorganic molecules, such as water, and organic molecules, such as DNA and proteins. The two complementary strands of DNA are held together by hydrogen bonds between complementary nucleotides (A&T, C&G).What happens if there is no hydrogen bond? ›
These bonds govern the way the molecules fold up, like DNA's double helix. They also change their bulk properties: without H bonding, it would take less energy to separate water molecules from each other so water would boil at a lower temperature.
How can hydrogen bonds be broken? ›
Hydrogen bonds are not strong bonds, but they make the water molecules stick together. The bonds cause the water molecules to associate strongly with one another. But these bonds can be broken by simply adding another substance to the water.Which is strongest bond? ›
In chemistry, a covalent bond is the strongest bond, In such bonding, each of two atoms shares electrons that bind them together. For example - water molecules are bonded together where both hydrogen atoms and oxygen atoms share electrons to form a covalent bond.Where are hydrogen bonds found in water? ›
In the case of water, hydrogen bonds form between neighboring hydrogen and oxygen atoms of adjacent water molecules. The attraction between individual water molecules creates a bond known as a hydrogen bond.Are hydrogen bonds weak or strong? ›
Hydrogen bonds are a strong type of dipole-dipole interaction. As a Rule of Thumb, they are weaker than covalent and ionic ("intramolecular") bonds", but stronger than most dipole-dipole interactions.What is a hydrogen bond symbol? ›
Hydrogen bonds are represented as H···Y system, where the dots represent the hydrogen bond. Liquids that display hydrogen bonding (such as water) are called associated liquids.What creates a hydrogen bond? ›
Hydrogen Bonding. Hydrogen bonding is a special type of dipole-dipole attraction between molecules, not a covalent bond to a hydrogen atom. It results from the attractive force between a hydrogen atom covalently bonded to a very electronegative atom such as a N, O, or F atom and another very electronegative atom.How many bonds hydrogen can form? ›
Hydrogen is an exception to the octet rule. H forms only one bond because it needs only two electrons.What type of bond is DNA? ›
Covalent bonds occur within each linear strand and strongly bond the bases, sugars, and phosphate groups (both within each component and between components). Hydrogen bonds occur between the two strands and involve a base from one strand with a base from the second in complementary pairing.Is DNA A chemical bond? ›
The two strands are connected by chemical bonds between the bases: adenine bonds with thymine, and cytosine bonds with guanine. The sequence of the bases along DNA's backbone encodes biological information, such as the instructions for making a protein or RNA molecule.Is DNA dependent on hydrogen bonds? ›
The stability of the DNA double helix depends on a fine balance of interactions including hydrogen bonds between bases, hydrogen bonds between bases and surrounding water molecules, and base-stacking interactions between adjacent bases.
What does hydrogen bonding do to water? ›
Hydrogen bonds cause water to be exceptionally attracted to each other. Therefore, water is very cohesive. We see evidence of water's cohesiveness every day – in water drops and in streams of water.Is hydrogen bonding important in RNA? ›
Hydrogen bonds between RNA nucleotides and protein residues play important functional role in RNA : protein complexes. To provide a structural rational of these hydrogen bonds, hydrogen bonds in X-ray crystal structures are identified and anatomized in all possible rational ways.Where are hydrogen bonds not found? ›
The hydrogen bonds are formed in compounds which have F or N or O with hydrogen. H2S does not have F or N or O, so it does not form a hydrogen bond.What are 5 things hydrogen is used for? ›
Other examples of hydrogen use include rocket fuel, welding, producing hydrochloric acid, reducing metallic ores and filling balloons, according to Los Alamos.What are the factors responsible for the strength of hydrogen bonds? ›
Strength of the hydrogen bond is determined by the coulombic interaction between the lone-pair electrons of the electronegative atom of one molecule and the hydrogen atom of other molecule.How do chemical bonds affect our everyday life? ›
The Proteins we need, Carbohydrates we eat are all result of chemical bonding between atoms. Gas we use in our car is a result of Chemical bonding. Oxygen ( O2 ) we breathe is a result of chemical bond. Medicines we need to cure ourselves are results of Chemical bonding between atoms.Which chemical bond is most important to life? ›
Covalent Bonds. Another type of strong chemical bond between two or more atoms is a covalent bond. These bonds form when an electron is shared between two elements and are the strongest and most common form of chemical bond in living organisms.What happens when chemical bonds are broken? ›
A chemical reaction occurs when chemical bonds are broken and formed and atoms are exchanged to produce chemically different species. Both of these processes are chemical reactions.What are the 5 characteristics of a bond? ›
- Face value. Corporate bonds normally have a par value of $1,000, but this amount can be much greater for government bonds.
- Interest. ...
- Coupon or interest rate. ...
- Maturity. ...
- Issuers. ...
- Rating agencies. ...
- Tools and tips.
Bonds form when atoms share or transfer valence electrons. Valence electrons are the electrons in the outer energy level of an atom that may be involved in chemical interactions. Valence electrons are the basis of all chemical bonds.
What is the weakest bond? ›
- Chemical bonds are formed by the interaction of molecules either in an attractive manner or in a repulsion manner.
- The weakest type of bonds are the Hydrogen bonds.
- Hydrogen bonds are formed when a Hydrogen atom is bonded to more electronegative atom.
Hint: Covalent bonds are known to be the strongest and the bonds formed via Van der Waals forces are known to be the weakest. The ranking from strongest to weakest bonds is: Covalent bond > ionic bond > hydrogen bond > Van der Waals forces.What are the 7 types of bonds? ›
Treasury bonds, GSE bonds, investment-grade bonds, high-yield bonds, foreign bonds, mortgage-backed bonds and municipal bonds - explained by Beth Stanton.Which bond type is best? ›
Government bonds are generally the safest, while some corporate bonds are considered the most risky of the commonly known bond types. For investors, the biggest risks are credit risk and interest rate risk. Since bonds are debts, if the issuer fails to pay back their debt, the bond can default.Does vegetable oil dissolve in water? ›
Water and oil do not mix. They are said to be immiscible. This is because water is a polar molecule – its structure means that is has a positive charge one end and a negative charge the other end.How much positive and negative charge is there in a water molecule? ›
Therefore, a water molecule has an equal amount of positive and negative charge which is 1.33×107C. Note:Water is formed by the sharing of electrons between two hydrogen atoms and one oxygen atom through the formation of a covalent bond.Why does the partial negative charge in a molecule of water occur? ›
Because oxygen is more electronegative—electron-greedy—than hydrogen, the Ostart text, O, end text atom hogs electrons and keeps them away from the Hstart text, H, end text atoms. This gives the oxygen end of the water molecule a partial negative charge, while the hydrogen end has a partial positive charge.What is hydrogen bond with example? ›
The hydrogen bond is a bond between the hydrogen atom and more electronegative elements like N, O, and F. Example: H−O−H,NH3,etc.What is hydrogen bond define with example? ›
For example, in water molecules (H2O), hydrogen is covalently bonded to the more electronegative oxygen atom. Therefore, hydrogen bonding arises in water molecules due to the dipole-dipole interactions between the hydrogen atom of one water molecule and the oxygen atom of another H2O molecule.What is hydrogen bonding and its types? ›
Hydrogen bond is a electrostatic attraction between a hydrogen atom which is bond to a more electronegative atom such as Nitrogen, Oxygen, fluorine. These are two types of hydrogen bonds :- 1) Intermolecular Hydrogen bonding :- It occurs between two separate molecules. Eq :- H−F...... H−F......
Is water a hydrogen bond? ›
In the case of water, hydrogen bonds form between neighboring hydrogen and oxygen atoms of adjacent water molecules. The attraction between individual water molecules creates a bond known as a hydrogen bond.What are the factors responsible for strength of hydrogen bond? ›
Strength of the hydrogen bond is determined by the coulombic interaction between the lone-pair electrons of the electronegative atom of one molecule and the hydrogen atom of other molecule.What are the two types of hydrogen bond? ›
- Intramolecular Hydrogen Bonding.
- Intermolecular Hydrogen Bonding.
A greater degree of hydrogen-bonding means the molecules are attracted to each other effectively . That is, they stick close together well, and thus, are hard to break apart. As a result, it is more difficult to deform the surface of water than the surface of ethyl alcohol.Are hydrogen bonds formed between all molecules? ›
Answer and Explanation: Hydrogen bonds do not form between all molecules. Hydrogen bonds only form between molecules that have polar covalent bonds between another atom and...What 3 properties are a result of hydrogen bonds? ›
Due to the extensive hydrogen bonding, water has some emergent properties that impact life on Earth in many ways. These include: Cohesion, Adhesion, High surface tension, High specific heat, High Heat of vaporization, and the fact that ice floats (Ice is less dense as a solid than liquid water).Are hydrogen bonds strong in water? ›
The water hydrogen bond is a weak bond, never stronger than about a twentieth of the strength of the O-H covalent bond. It is strong enough, however, to be maintained during thermal fluctuations at, and below, ambient temperatures.