Question

Several \(\beta\)-amino acids exist. There is a unit of \(\beta\)-alanine, for example, contained within the structure of coenzyme A (Problem 25.34). Write the structural formula of \(\beta\)-alanine.

Short answer

Answer: The structural formula of β-alanine is NH2 - CH(CH3) - COOH.

Step-by-step solution

Understand \(\beta\)-alanine structure

\(\beta\)-alanine is a type of amino acid which contains an amino group, a carboxyl group, and a side chain. The general structure of an amino acid can be represented as: NH2 - C(R) - COOH Where R represents the side chain. In case of \(\beta\)-alanine, our goal is to find the side chain (R group) and create its structural formula accordingly.

Identify the side chain of \(\beta\)-alanine

In \(\beta\)-alanine, there is an extra carbon between the amino group and the side chain, which gives it the name "beta". The simplest form of the side chain for \(\beta\)-alanine is a methyl group (CH3). Therefore, the side chain for \(\beta\)-alanine is: H2C - CH3

Combine the general amino acid structure and side chain

Now we have the side chain for \(\beta\)-alanine, we can create the structural formula by combining it with the general amino acid structure: NH2 - CH(CH3) - COOH

Finalize the structural formula

The final structural formula for \(\beta\)-alanine is: NH2 - CH(CH3) - COOH

Key concepts

Amino Acids Structure

Understanding the structure of amino acids is crucial in the study of biochemistry and molecular biology. All amino acids share a common backbone, which consists of an amino group (\( -NH_2 \)), a carboxyl group (\( -COOH \)), and a distinctive side chain, known as an R group, attached to the alpha carbon (the central carbon atom). Amino acids are classified according to the properties of their side chains.

For instance, \( \beta \-alanine \) is a \( \beta \-amino acid \) with its amino group attached to the \( \beta \) carbon, which is the second carbon away from the carboxyl group. The side chain of \( \beta \-alanine \) is a simple methyl group (\( -CH_3 \)), leading to the structural formula \( NH_2 - CH(CH_3) - COOH \).

When examining the structure of \( \beta \-alanine \) or any amino acid, it's essential to remember that the spatial arrangement is important for their function. While this formula represents the linear arrangement of atoms, in reality, amino acids exist in three-dimensional space and can have different isomers, such as L and D forms based on the orientation of their atoms.

Coenzyme A

Coenzyme A (CoA) is a critical cofactor in various enzymatic reactions, especially in the synthesis and oxidation of fatty acids as well as the oxidation of pyruvate in the citric acid cycle. The molecule plays a central role in transferring acyl groups and is composed of adenosine triphosphate (ATP), cysteine, and pantothenic acid, among other components.

\( \beta \-Alanine \) is a key building block within the structure of Coenzyme A. Specifically, pantothenic acid, which is a part of CoA, includes a \( \beta \-alanine \) unit directly in its structure. Understanding how \( \beta \-alanine \) fits into larger biochemical constructs like CoA demonstrates the interconnectivity of molecular structures in biological systems.

In CoA, \( \beta \-alanine \) is not free but rather linked to other molecules, contributing to CoA's intricate and multi-functional structure. Its inclusion in CoA highlights the relevance of individual amino acids outside of protein synthesis and underscores the importance of these molecules in a broad array of metabolic processes.

Organic Chemistry Education

Organic chemistry education involves understanding the composition, structure, properties, and reactions of carbon-containing compounds. The study encompasses a vast range of substances, including biomolecules like amino acids, carbohydrates, and nucleic acids, as well as synthetic polymers and small-molecule drugs.

The challenge with teaching and learning organic chemistry often lies in its complexity and the abstract nature of the concepts involved. Simplifying these concepts for better understandability, such as breaking down compounds into functional groups and core structures, is a fundamental educational strategy.

Visualization and Model Building

One effective educational tool is the use of molecular models to visualize the spatial arrangements of molecules. Additionally, interactive online platforms and simulation software can bring these concepts to life for students.

Contextual Learning

Connecting organic chemistry concepts to real-world applications, such as the role of \( \beta \-alanine \) in coenzyme A and metabolism, makes the learning process more relevant and engaging. By focusing on the concrete applications of these organic compounds, students can appreciate the direct impact of organic chemistry in both natural and technological realms.