Which of the following is the energy currency of cells?

Options

A. ATP
B. ADP
C. DNA
D. RNA

Answer

To determine which of the following is the energy currency of cells, we need to analyze the given options: ATP, ADP, DNA, and RNA.

### Step-by-Step Solution:

1. **Understanding Energy Currency**: The term "energy currency" refers to a molecule that stores and provides energy for metabolic activities within the cell.

2. **Analyzing ATP**:
- ATP stands for adenosine triphosphate.
- It consists of a nucleoside (adenosine) attached to three phosphate groups.
- The bonds between these phosphate groups are high-energy bonds. When these bonds break, energy is released, which can be used for various cellular processes.

3. **Analyzing ADP**:
- ADP stands for adenosine diphosphate.
- It has only two phosphate groups and is formed when one phosphate group is removed from ATP.
- Although ADP can convert back to ATP by adding an inorganic phosphate, it does not serve as the primary energy currency because it contains less energy compared to ATP.

4. **Analyzing DNA and RNA**:
- DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are nucleic acids that carry genetic information.
- They are not involved in energy transfer or storage in the same way ATP does. Their primary roles are related to heredity and protein synthesis.

5. **Conclusion**: Based on the analysis, ATP is the molecule that serves as the energy currency of the cell due to its ability to store and release energy through the breaking of its high-energy phosphate bonds.

### Final Answer:
The energy currency of cells is **ATP (adenosine triphosphate)**.

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