What kind of reaction is in terms of energy input/output in biological macrmolecules polymers
The correct answer and explanation is:
Correct Answer: The formation of biological macromolecule polymers involves a dehydration synthesis (condensation) reaction, which is an endergonic reaction (requires energy input).
Explanation (300 words):
In biological systems, macromolecules such as proteins, nucleic acids (DNA/RNA), and polysaccharides are formed through the linking of smaller units called monomers. For example:
- Amino acids join to form proteins.
- Nucleotides join to form nucleic acids.
- Simple sugars (like glucose) link to form polysaccharides (like starch or cellulose).
The chemical reaction responsible for polymer formation is known as dehydration synthesis, also called a condensation reaction. In this process, a water molecule (H₂O) is removed when two monomers are joined together. For example, when two amino acids link, the -OH group from one and the -H from another are removed, forming water and a peptide bond.
This type of reaction is endergonic, meaning it requires energy input to proceed. In living organisms, this energy is typically provided by molecules like ATP (adenosine triphosphate). For instance, during protein synthesis, ATP is used during translation to assemble amino acids into polypeptide chains.
This energy requirement occurs because the formation of bonds in polymers is not energetically favorable by itself. The system must absorb energy to overcome the activation energy barrier and drive the formation of stable covalent bonds between monomers.
In contrast, breaking down polymers (e.g., during digestion) is usually an exergonic process — it releases energy and often involves hydrolysis (adding water to break the bond).
In summary, the synthesis of biological macromolecule polymers involves dehydration synthesis reactions that are endergonic, requiring energy input. This energy investment is vital for building the complex molecules necessary for life, including enzymes, genetic material, and structural components of cells.