Question

Would you expect the biosynthesis of a protein from the constituent amino acids in an organism to be an exergonic or endergonic process? Give the reason for your answer.

Short answer

Endergonic. Protein biosynthesis requires energy input to form complex structures from amino acids.

Step-by-step solution

Understand the Terms

First, understand the terminology. An exergonic process releases energy, while an endergonic process requires an input of energy.

Analyze the Process

Biosynthesis of proteins involves assembling amino acids into a complex structure. This process forms peptide bonds and creates a higher-order structure from simpler molecules.

Determine Energy Requirements

Creating a complex structure from simpler molecules usually requires input of energy to drive the reactions forward. The assembly and formation of peptide bonds between amino acids are non-spontaneous and need energy.

Conclusion

Given that the process of protein biosynthesis involves creating higher-order structures from simpler components, this process is endergonic, meaning it requires an input of energy.

Key concepts

Endergonic Process

Endergonic processes are a fundamental concept in biochemistry and general biology. In simple terms, an endergonic process is one that requires an input of energy to proceed. These processes are non-spontaneous, meaning they do not occur naturally without energy being added.
Think of endergonic reactions as uphill movements; they need energy to push molecules into a state of higher energy. This energy is usually derived from ATP (adenosine triphosphate) in biological systems.
In the biosynthesis of proteins, the creation of new peptide bonds between amino acids is endergonic. Energy is required to link these smaller molecules into a complex and functional protein.

Peptide Bond Formation

Understanding protein biosynthesis requires a grasp of peptide bond formation. This is the process where individual amino acids are linked together to form a protein.
Peptide bonds are unique types of covalent bonds between the amino group of one amino acid and the carboxyl group of another. The formation of these bonds is not a spontaneous event and requires an input of energy.
During peptide bond formation, a molecule of water is released in a reaction called a dehydration synthesis. This process needs energy to start the reaction and make it proceed to completion.
This is why the assembly of amino acids into proteins is an endergonic process; energy is used to create the peptide bonds that hold the protein structure together.

Biosynthesis of Proteins

The biosynthesis of proteins is a critically important process in living organisms. It involves assembling amino acids into highly specific sequences to form functional proteins.
For this to occur, cells use machinery like ribosomes in a process that is highly regulated and requires energy. The ribosome reads the mRNA sequence and, with the help of tRNA, brings the correct amino acids into place.
Each step in the biosynthesis of proteins, from the initiation to the elongation of the polypeptide chain and finally the termination, is energy-dependent. ATP and GTP are the primary sources of this energy.
Because of its high energy demands, protein biosynthesis is inherently an endergonic process. The energy required ensures that proteins are assembled correctly, folding into complex structures essential for their biological functions.