Net gain of ATP molecules, during aerobic respiration, in heart cells is

Options

A. 40 molecules
B. 48 molecules
C. 36 molecules
D. 38 molecules

Answer

To determine the net gain of ATP molecules during aerobic respiration in heart cells, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Aerobic Respiration**:
- Aerobic respiration occurs in the presence of oxygen and is the process by which cells convert glucose into energy (ATP).
- It involves several stages, including glycolysis, the Krebs cycle, and the electron transport chain.

2. **Total ATP Production**:
- During aerobic respiration, the theoretical maximum yield of ATP is typically around 38 molecules per glucose molecule. This includes ATP produced during glycolysis, the Krebs cycle, and oxidative phosphorylation.

3. **ATP Utilization**:
- However, not all of these ATP molecules are available for cellular work. Some ATP is used for transporting NADH (produced during glycolysis) into the mitochondria, where it can be further oxidized.
- In heart cells, the transport of NADH into the mitochondria consumes energy, which reduces the net gain of ATP.

4. **Calculating Net Gain**:
- If we start with the theoretical maximum of 38 ATP molecules and account for the 2 ATP molecules used in the transport of NADH, we subtract these from the total.
- Therefore, the net gain of ATP in heart cells = 38 ATP - 2 ATP = 36 ATP.

5. **Final Answer**:
- The net gain of ATP molecules during aerobic respiration in heart cells is **36 ATP molecules**.