Which functional group acts as an acid

Carboxylic acid is a combination of a carbonyl group and a hydroxyl group attached to the same carbon, resulting in new characteristics.

This results in a delocalized negative charge on the remaining oxygen atoms. The carboxyl group is very versatile. In its protonated state, it can form hydrogen bonds with other polar compounds.

In its deprotonated states, it can form ionic bonds with other positively charged compounds. This will have several biological consequences that will be explored more when we discuss enzymes. Can you identify all the carboxyl groups on the macromolecules shown above?

The amino group consists of a nitrogen atom attached by single bonds to hydrogen atoms. An organic compound that contains an amino group is called an amine. Like oxygen, nitrogen is also more electronegative than both carbon and hydrogen which results in the amino group displaying some polar character. Amino groups can also act as bases, which means that the nitrogen atom can bond to a third hydrogen atom as shown in the image below.

Once this occurs, the nitrogen atom gains a positive charge and can now participate in ionic bonds. The amine functional group can exist in a deprotonated or protonated state. When protonated the nitrogen atom is bound to three hydrogen atoms and has a positive charge. The deprotonated form of this group is neutral. Attribution: Created Erin Easlon Own work. The oxygen atoms are more electronegative than the phosphorous atom resulting in polar covalent bonds. Phosphate groups also contain a negative charge and can participate in ionic bonds.

Phosphate groups are common in nucleic acids and on phospholipids the term "phospho" referring to the phosphate group on the lipid. Below are images of a nucleotide monophosphate A and a phosphoserine B.

Water is a unique substance whose special properties are intimately tied to the processes of life. Water solvates or "wets" the cell and the molecules in it, plays a key role as reactant or product in innumerable number of biochemical reactions, and mediates the interactions between molecules in and out of the cell.

Thus CO2 is not a polar molecule, even though it has polar bonds. In Bis2a, the ubiquitous role of water in nearly all biological processes is easy to overlook by getting caught up in the details of specific processes, proteins, the roles of nucleic acids, and in your excitement for molecular machines it'll happen.

However water plays key roles in all of those processes and we will need to continuously stay aware of the role that water is playing if we are to develop a better functional understanding. Be on the lookout and also pay attention when your instructor points this out. In a liquid state, individual water molecules interact with one another through a network of dynamic hydrogen bonds that are constantly forming and breaking H bonds are relatively weak bonds.

By contrast, molecules with more non-polar character such as oils and fats do not interact well with water and separate from it rather than dissolve in it, as we see in salad dressings containing oil and vinegar an acidic water solution. We will consider the some of the energetic components of these types of reactions in other another chapter. In a liquid state water forms a dynamic network of hydrogen bonds between individual molecules.

Shown are one donor-acceptor pair. Since water is a polar molecule with slightly positive and slightly negative charges, ions and polar molecules can readily dissolve in it.

Therefore, water is referred to as a solvent , a substance capable of dissolving other polar molecules and ionic compounds. The charges associated with these molecules will form hydrogen bonds with water, surrounding the particle with water molecules.

Characterized by central C bound to O and OH. Characterized by presence of N. What functional groups can be found in a fructose molecule? Leucine is an amino acid that plays an important role in muscle development. What functional groups can be found in a leucine molecule? Hydrogen bonds between functional groups within the same molecule or between different molecules are important to the function of many macromolecules and help them to fold properly into and maintain the appropriate shape for functioning.

Hydrogen bonds are also involved in various recognition processes, such as DNA complementary base pairing and the binding of an enzyme to its substrate, as illustrated in Figure 1. Figure 1. Hydrogen bonds connect two strands of DNA together to create the double-helix structure. The unique properties of carbon make it a central part of biological molecules.

Carbon binds to oxygen, hydrogen, and nitrogen covalently to form the many molecules important for cellular function. Carbon has four electrons in its outermost shell and can form four bonds. Carbon and hydrogen can form hydrocarbon chains or rings. Functional groups are groups of atoms that confer specific properties to hydrocarbon or substituted hydrocarbon chains or rings that define their overall chemical characteristics and function.

Amines also display some solubility in water. However, the solubility decreases with an increase in carbon atoms, due to the increased hydrophobicity of the compound as the chain length increases. Aliphatic amines, which are amines connected to an alkyl chain, display solubility in organic polar solvents. Aromatic amines, which are amines that participate in a conjugated ring, donate their lone pair of electrons into the benzene ring, and thus their ability to engage in hydrogen bonding decreases.

This results in a decrease in their solubility in water and high boiling points. Amines are bases, and their basicity depends on the electronic properties of the substituents alkyl groups enhance the basicity; aryl groups diminish it , steric hindrance, and the degree of solvation of the protonated amine. In general, the effect of alkyl groups raises the energy of the lone pair of electrons, thus elevating the basicity. Thus, the basicity of an amine can be expected to increase with the number of alkyl groups on the amine.

Additionally, the effect of the aromatic ring delocalizes the lone pair of electrons on nitrogen into the ring, resulting in decreased basicity. The solvation of protonated amines changes upon their conversion to ammonium compounds. Quaternary ammonium salts usually exhibit the lowest solubility of the series.

Imine formation : A primary amine is reacted with an aldehyde to produce an imine. Industrially, amines are prepared from ammonia by alkylation with alcohols. They can also be prepared via reduction of nitriles to amines using hydrogen in the presence of a nickel catalyst. Amines are quite reactive due to their basicity as well as their nucleophilicity. Most primary amines are good ligands and react with metal ions to yield coordination complexes.

One of the most important reactions for amines is their formation of imines, or organic compounds where nitrogen participates in a double bond, upon reacting with ketones or aldehydes. Amines are ubiquitous in biology. Many important molecules are amine-based, such as neurotransmitters and amino acids. Their applications in the world include being starting material for dyes and models for drug design.

They are also used for gas treatment, such as removing CO 2 from combustion gases. Privacy Policy. Skip to main content. Organic Chemistry. Search for:. Functional Group Names, Properties, and Reactions Functional Groups Functional groups refer to specific atoms bonded in a certain arrangement that give a compound certain physical and chemical properties.

Functional groups will undergo the same type of reactions regardless of the compound of which they are a part; however, the presence of certain functional groups within close proximity can limit reactivity.

Functional groups can be used to distinguish similar compounds from each other. Key Terms functional group : A specific grouping of elements that is characteristic of a class of compounds, and determines some properties and reactions of that class. Alcohols Alcohols are functional groups characterized by the presence of an -OH group. Learning Objectives Identify the general properties of the alcohol functional group. This leads to higher boiling points compared to their parent alkanes.

Alcohols are polar in nature. This is attributed to the difference in electronegativity between the carbon and the oxygen atoms. In chemical reactions, alcohols often cannot leave the molecule on their own; to leave, they often become protonated to water, which is a better leaving group.

Alcohols also can become deprotonated in the presence of a strong base. Key Terms alkane : Any of the saturated hydrocarbons—including methane, ethane, and compounds with long carbon chain known as paraffins, etc.

Ethers Ethers are a class of organic compounds characterized by an oxygen atom connected to two alkyl or aryl groups. Key Takeaways Key Points Ethers have relatively low boiling points due to their inability to form hydrogen bonds with each other.

Due to the electronegativity difference between the oxygen and carbon atoms of an ether, the molecule is slightly polar. Although they have low reactivity overall, the two lone pairs of electrons on the oxygen atom do afford the ether molecule some reactivity; the ether molecule is subject to reacting with strong acids and serves as a Lewis base.

Key Terms alkene : An unsaturated, aliphatic hydrocarbon with one or more carbon—carbon double bond. Learning Objectives Identify the general properties of ketones and aldehydes. Key Takeaways Key Points The carbonyl functional group is a carbon double bonded to an oxygen. Depending on the location of the carbonyl group, it is termed differently; ketones contain the carbonyl inside the compound and aldehydes contain the carbonyl at the end of the organic compound. Ketones and aldehydes can undergo keto- enol tautomerism.

This refers to the equilibrium between the two possible tautomers. The interconversion of the two forms involves the movement of a proton and the shifting of bonding electrons. This equilibrium affords the compounds more reactivity. Ketones and aldehydes participate in a variety of reactions. They can undergo oxidation reactions, in which they become oxidized to the corresponding carboxylic acids. Key Terms tautomerism : A form of isomerism in which a dynamic equilibrium between multiple isomers exists, such as that between an enol and a ketone.

The 2s orbital is mixed with only two of the three 2p orbitals. Carboxylic Acids Carboxylic acids are organic acids that contain a carbon atom that participates in both a hydroxyl and a carbonyl functional group. Learning Objectives Recognize the general properties of carboxylic acids. Key Takeaways Key Points Carboxylic acids are used as precursors to form other compounds such as esters, aldehydes, and ketones. Carboxylic acids can exhibit hydrogen bonding with themselves, especially in non- polar solvents; this leads to increased stabilization of the compounds and elevates their boiling points.

Since they contain both hydroxyl and carbonyl functional groups, carboxylic acids participate in hydrogen bonding as both hydrogen acceptors and hydrogen donors. Esters Esters are functional groups produced from the condensation of an alcohol with a carboxylic acid, and are named based on these components.

Learning Objectives Identify the general properties of the ester functional group. Key Takeaways Key Points Esters are a functional group commonly encountered in organic chemistry. They are characterized by a carbon bound to three other atoms: a single bond to a carbon, a double bond to an oxygen, and a single bond to an oxygen.

The singly bound oxygen is bound to another carbon. Ester names are derived from the parent alcohol and the parent acid. The carbonyl is weakly electrophilic, but is attacked by strong nucleophiles. Key Terms carboxylic acid : Any of a class of organic compounds containing a carboxyl functional group—a carbon with one double bond to an oxygen and a single bond to another oxygen, which is in turn bonded to a hydrogen. Amines Amines are compounds characterized by the presence of a nitrogen atom, a lone pair of electrons, and three substituents.

Learning Objectives Identify the general properties of amines. Key Takeaways Key Points Due to the lone pair of electrons, amines are basic compounds. The basicity of the compound can be influenced by neighboring atoms, steric bulk, and the solubility of the corresponding cation to be formed. Amine compounds can hydrogen bond, which affords them solubility in water and elevated boiling points. The general structure of an amine is a nitrogen atom with a lone pair of electrons and three substituents.

However, the nitrogen may bind to four substituents, leaving a positive charge on the nitrogen atom. These charged species can serve as intermediates for important reactions. Key Terms aliphatic : Of a class of organic compounds in which the carbon atoms are arranged in an open chain. Licenses and Attributions. CC licensed content, Shared previously.