Which part of a cell performs each of the following functions :
Releases energy by oxidising sugar.

Explanation

**Step-by-Step Solution:**

1. **Identify the Function**: The function we need to address is the release of energy by oxidizing sugar. This process is essential for cellular activities and overall metabolism.

2. **Understand the Process**: The release of energy from sugar involves a biochemical process known as cellular respiration. During this process, glucose (a type of sugar) is oxidized, which means it is broken down in the presence of oxygen to release energy.

3. **Locate the Cell Part**: The part of the cell responsible for carrying out cellular respiration is the mitochondria. Mitochondria are often referred to as the "powerhouse of the cell" because they generate adenosine triphosphate (ATP), the energy currency of the cell.

...