Name the site(s) where breakdown of complex molecules takes palce to yield energy

Answer

**Step-by-Step Solution:**

1. **Identify the Process of Energy Yielding**: The breakdown of complex molecules to yield energy is primarily associated with cellular respiration, which occurs in two main stages: glycolysis and the Krebs cycle (or citric acid cycle).

2. **First Site - Cytoplasm**: The first site where the breakdown of complex molecules occurs is the cytoplasm. In this stage, glucose, a six-carbon compound, undergoes glycolysis. During glycolysis, glucose is split into two molecules of pyruvate (a three-carbon compound), yielding a small amount of energy in the form of ATP (adenosine triphosphate).

3. **Second Site - Mitochondria**: The second site is the mitochondria. Here, the pyruvate produced in glycolysis is further oxidized in the Krebs cycle. This process involves the complete oxidation of glucose and results in the production of additional ATP, as well as electron carriers (NADH and FADH2) that are used in the electron transport chain to generate even more ATP.

4. **Conclusion**: Therefore, the sites where the breakdown of complex molecules takes place to yield energy are the cytoplasm (for glycolysis) and the mitochondria (for the Krebs cycle and oxidative phosphorylation).

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