Of the following functional groups, which is/are polar, tending to make organic compounds hydrophilic?
a. Carbonyl
b. Amino
c. Hydroxyl
d. All of the above

Verified step by step guidance

1. Understand the concept of polarity: Polar functional groups have an uneven distribution of electrons, leading to partial positive and negative charges. This makes them hydrophilic, meaning they interact well with water.
2. Examine the carbonyl group: The carbonyl group (C=O) consists of a carbon atom double-bonded to an oxygen atom. Oxygen is highly electronegative, creating a polar bond. Therefore, the carbonyl group is polar and hydrophilic.
3. Analyze the amino group: The amino group (-NH₂) contains nitrogen, which is electronegative and forms polar bonds with hydrogen. This makes the amino group polar and hydrophilic.
4. Evaluate the hydroxyl group: The hydroxyl group (-OH) consists of an oxygen atom bonded to a hydrogen atom. Oxygen's electronegativity creates a polar bond, making the hydroxyl group hydrophilic.
5. Conclude based on the analysis: Since all three functional groups (carbonyl, amino, and hydroxyl) are polar and hydrophilic, the correct answer is 'all of the above.'

Key Concepts

Functional Groups

Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. They determine the properties of organic compounds, including their polarity and solubility. Common functional groups include hydroxyl, carbonyl, and amino groups, each influencing the behavior of the compound in biological systems.

Polarity

Polarity refers to the distribution of electrical charge over the atoms in a molecule. A polar molecule has a partial positive charge on one side and a partial negative charge on the other, leading to an uneven distribution of charge. This property affects how molecules interact with each other, particularly in terms of solubility in water, where polar molecules tend to be hydrophilic (water-attracting).

Hydrophilicity

Hydrophilicity is the property of a substance to interact favorably with water, often due to the presence of polar functional groups. Compounds that are hydrophilic can dissolve in water, making them essential in biological processes. Functional groups like hydroxyl (-OH), amino (-NH2), and carbonyl (C=O) contribute to this property, allowing organic molecules to participate in biochemical reactions in aqueous environments.