Questions: Which of the following is TRUE about the phosphate molecules in ATP? Phosphates are the only building block of ATP. Phosphate-to-phosphate bonds are the only high-energy bonds in ATP. All the phosphate groups bind by glycoside bonds to the adenine. Phosphates are not part of any biochemical compounds.

The answer is the second one: Phosphate-to-phosphate bonds are the only high-energy bonds in ATP.

Explanation for each option:

1. Phosphates are the only building block of ATP.
   This is incorrect. ATP (adenosine triphosphate) is composed of three main components: adenine (a nitrogenous base), ribose (a five-carbon sugar), and three phosphate groups. Therefore, phosphates are not the only building block of ATP.

2. Phosphate-to-phosphate bonds are the only high-energy bonds in ATP.
   This is correct. The high-energy bonds in ATP are specifically the bonds between the phosphate groups, known as phosphoanhydride bonds. These bonds release energy when broken, which is used by the cell for various processes.

3. All the phosphate groups bind by glycoside bonds to the adenine.
   This is incorrect. Glycosidic bonds are not involved in binding phosphate groups to adenine. Instead, the phosphate groups are connected to each other by phosphoanhydride bonds and to the ribose sugar by a phosphoester bond.

4. Phosphates are not part of any biochemical compounds.
   This is incorrect. Phosphates are a crucial component of many biochemical compounds, including nucleotides like ATP, DNA, and RNA, as well as phospholipids in cell membranes.

In summary, the correct statement about the phosphate molecules in ATP is that the phosphate-to-phosphate bonds are the only high-energy bonds in ATP.