Respiration involves breaking of _____ bonds of complex compounds through oxidation within the cells, leading to release of considerable amount of energy.

Options

A. C-C
B. C-O
C. C-H
D. Both (2) & (3)

Answer

To answer the question, "Respiration involves breaking of _____ bonds of complex compounds through oxidation within the cells, leading to the release of a considerable amount of energy," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Respiration**: Respiration is a biochemical process where complex organic compounds, primarily glucose, are broken down to release energy. This process occurs in the cells and involves oxidation reactions.

2. **Identifying the Bonds**: In the context of respiration, we need to identify which bonds are broken during the oxidation of glucose. The main types of bonds in glucose are:
- Carbon-carbon (C-C) bonds
- Carbon-hydrogen (C-H) bonds
- Carbon-oxygen (C-O) bonds

3. **Analyzing the Oxidation of Glucose**: The chemical equation for aerobic respiration can be represented as:
\[ C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{energy} \]
Here, glucose (C6H12O6) is oxidized in the presence of oxygen (O2) to produce carbon dioxide (CO2), water (H2O), and energy.

4. **Breaking Down the Bonds**: During this process:
- The C-C bonds in glucose are broken, leading to the formation of CO2.
- The C-H bonds are also broken, contributing to the release of energy.
- C-O bonds are involved but are not the primary bonds broken for energy release.

5. **Conclusion**: The bonds that are primarily responsible for the release of energy during respiration are the carbon-carbon (C-C) bonds. Therefore, the correct answer to fill in the blank is "carbon-carbon."

### Final Answer:
Respiration involves breaking of **carbon-carbon** bonds of complex compounds through oxidation within the cells, leading to the release of a considerable amount of energy.

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