Question

Write a chemical equation for the formation of threonylaspartic acid from the constituent amino acids, assuming that the reaction is made possible by enzymatic catalysis.

Short answer

The chemical equation for the formation of threonylaspartic acid from L-threonine and L-aspartic acid with enzymatic catalysis is: \[ L-threonine + L-aspartic\ acid + Enzyme \rightarrow Threonylaspartic\ acid + H_2O + Enzyme \] Or, using the structural formulas: \[ HO_2CCH(NH_2)CH(OH)CH_3 + HO_2CCH(NH_2)CH_2CO_2H + Enzyme \rightarrow HO_2CCH(NHCH_2CO_2H)CH(OH)CH_3 + H_2O + Enzyme \]

Step-by-step solution

Identify the amino acids involved

Threonylaspartic acid is a dipeptide formed by the amino acids L-threonine and L-aspartic acid. We will begin by writing their structural formulas.

Write the structural formulas for L-threonine and L-aspartic acid

- L-threonine has the structural formula: HO₂CCH(NH₂)CH(OH)CH₃; - L-aspartic acid has the structural formula: HO₂CCH(NH₂)CH₂CO₂H.

Determine the bond formed between the amino acids

In the formation of a peptide bond, the amine group (-NH₂) of one amino acid reacts with the carboxyl group (-COOH) of another amino acid, releasing a water molecule (H₂O). Enzymatic catalysis facilitates this reaction. So, the peptide bond will be formed between the -NH₂ group from the aspartic acid and the -COOH group from the threonine: HO₂CCH(NH₂)CH(OH)CH₃ + HO₂CCH(NH₂)CH₂CO₂H + Enzyme → HO₂CCH(NHCH₂CO₂H)CH(OH)CH₃ + H₂O + Enzyme

Write the chemical equation for the formation of threonylaspartic acid

The chemical equation for the formation of threonylaspartic acid from L-threonine and L-aspartic acid with enzymatic catalysis is: \[ L-threonine + L-aspartic\ acid + Enzyme \rightarrow Threonylaspartic\ acid + H_2O + Enzyme \] Or, using the structural formulas: \[ HO_2CCH(NH_2)CH(OH)CH_3 + HO_2CCH(NH_2)CH_2CO_2H + Enzyme \rightarrow HO_2CCH(NHCH_2CO_2H)CH(OH)CH_3 + H_2O + Enzyme \]

Key concepts

Amino Acids

Amino acids are the fundamental building blocks of proteins. They play a crucial role in forming peptide bonds, which link amino acids together to form proteins. Each amino acid consists of a central carbon atom, also known as the alpha carbon, which is bonded to four different groups: an amino group \((-NH_2)\), a carboxyl group \((-COOH)\), a hydrogen atom \((-H)\), and a variable side chain symbolized by \(R\) that determines the specific characteristics and properties of the amino acid.
In the context of peptide bond formation, the amino group of one amino acid interacts with the carboxyl group of another. This results in the release of a water molecule and the formation of a covalent bond called a peptide bond.

• The 20 standard amino acids are each defined by distinctive side chains which can be polar, nonpolar, acidic, or basic.
• Two amino acids mentioned in the exercise are L-threonine and L-aspartic acid.
• Both amino acids have different structural formulas, contributing unique characteristics that aid in the formation of the dipeptide, threonylaspartic acid.

Understanding the distinct properties of each amino acid allows a deeper comprehension of how complex proteins are constructed from such simple compounds.

Enzymatic Catalysis

Enzymatic catalysis is a process whereby enzymes, which are biological catalysts, speed up chemical reactions without being consumed in the process. Enzymes achieve this by lowering the activation energy required for the reaction to proceed, ensuring that reactions occur more efficiently and rapidly.
In the formation of peptide bonds between amino acids, enzymes play a critical role in orchestrating these reactions, ensuring they occur swiftly and correctly within the cellular environment.

• Enzymes are highly specific, meaning they only catalyze specific reactions with particular substrates.
• During the formation of peptide bonds, enzymes aid in aligning the amino acids properly to facilitate the reaction.
• They also stabilize the transition state, reducing the activation energy needed for the reaction to occur.

Without enzymes, the formation of complex proteins from amino acids would be an inefficient and time-consuming process. They ensure the diversity of life-sustaining biochemical reactions continues seamlessly.

Chemical Equation

Chemical equations are symbolic representations of chemical reactions. In a chemical equation, the reactants, which are the starting substances, are written on the left side, and the products, which are the substances formed, are written on the right side. An arrow separates reactants and products, indicating the direction of the reaction.
Writing a chemical equation for peptide bond formation involves depicting the conversion of individual amino acids into a dipeptide, with the assistance of an enzyme.

• The reaction begins with two amino acids: L-threonine and L-aspartic acid.
• An enzyme facilitates the removal of water (H₂O), enabling the bond formation.
• The resulting dipeptide, threonylaspartic acid, is the product of this biochemical reaction.

For the exercise, the chemical equation using structural formulas is expressed as:\[ HO_2CCH(NH_2)CH(OH)CH_3 + HO_2CCH(NH_2)CH_2CO_2H + Enzyme \rightarrow HO_2CCH(NHCH_2CO_2H)CH(OH)CH_3 + H_2O + Enzyme \]
This equation concisely shows reactants transforming into products, highlighting the role of enzymatic catalysis in biochemical processes.