The molecule best described as energy-rich because of the amount of energy that can be stored in it and released from it is glucose ([tex]$C_6H_{12}O_6$[/tex]).
Glucose ([tex]$C_6H_{12}O_6$[/tex]) is a carbohydrate that serves as a primary energy source for living organisms. It stores a significant amount of chemical energy in its bonds, particularly in the multiple C-H (carbon-hydrogen) bonds. When glucose is metabolized through cellular respiration, it releases energy that can be harnessed by the cell for various biological processes, such as movement, growth, and reproduction.
Let’s briefly discuss why the other molecules are not the correct choice:
- Carbon dioxide ([tex]$CO_2$[/tex]): This molecule is a byproduct of cellular respiration and is considered low in energy because it is a fully oxidized form of carbon. It does not store significant chemical energy.
- Adenosine diphosphate (ADP): While ADP is involved in energy storage and transfer within cells, it itself is not as energy-rich as its counterpart, adenosine triphosphate (ATP). ATP is the molecule that cells directly use for energy, and ADP becomes ATP when it gains an additional phosphate group.
- Water ([tex]$H_2O$[/tex]): Water is a stable molecule and does not store a significant amount of chemical energy. It plays a critical role in many biochemical reactions but is not considered an energy-rich molecule.
Therefore, due to its ability to store and release a significant amount of energy through its metabolism, glucose ([tex]$C_6H_{12}O_6$[/tex]) is the molecule best described as energy-rich.
