Chapter 1: Problem 7
Which of the following functional groups are found in phenylalanine?A. alkyl, double bond and aromatic ring B. amine, carboxylic acid and aromatic ring C. double bond, amide, and alcohol D. aromatic ring, halide and ketone
Short Answer
Step by step solution
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Aromatic Ring
One well-known example of an aromatic ring in biochemistry is the benzene ring in phenylalanine. This amino acid contains a six-membered benzene ring, contributing to its aromaticity.
This structure makes phenylalanine easily recognizable and important in various biological processes.
- Aromatic rings are stable due to resonance stabilization, where electron density is evenly spread across all atoms.
- They often have a distinct smell, which is where the term 'aromatic' originates.
- Common aromatic rings include benzene, toluene, and phenol.
Amine Group
In phenylalanine, the amine group is a primary amine, denoted by -NH2. This group is essential because it allows phenylalanine to form peptide bonds with other amino acids, constructing proteins.
- Amines act as bases in chemical reactions, accepting protons (H+) due to the lone pair of electrons on the nitrogen.
- The presence of an amine group can affect the polarity and solubility of molecules.
- Examples of amine-containing molecules include amino acids, neurotransmitters like dopamine, and drugs like amphetamines.
Carboxylic Acid
In phenylalanine, the carboxylic acid group is crucial for forming peptide bonds, similar to the amine group. It’s denoted by -COOH and contributes to the overall acidic nature of the molecule.
- Carboxylic acids are weak acids, partially dissociating in water to release hydrogen ions (H+).
- They have higher boiling points compared to other alcohols and ethers of similar molecular weight due to hydrogen bonding.
- Common examples include acetic acid (vinegar), citric acid (found in citrus fruits), and fatty acids in fats and oils.