Question

Lactic acid fermentation occurs in (a) Some bacteria (b) Muscle cell under anaerobic condition (c) Both (a) and (b) (d) Aerobic condition

Short answer

The correct answer is option (c) Both (a) and (b). Lactic acid fermentation can occur in both some bacteria and muscle cells under anaerobic conditions.

Step-by-step solution

Understand Lactic Acid Fermentation

Lactic Acid Fermentation is a metabolic process that occurs during the production of ATP (Adenosine Triphosphate) molecules without needing oxygen. It happens when the body needs energy quickly, and there isn’t enough oxygen available to finish the process. This is commonly in muscle cells during rapid and vigorous exercise.

Relating the Conditions to the Choices

Given the information from step 1, we can determine that option (b) 'Muscle cell under anaerobic condition' is correct as lactic acid fermentation occurs when there is a lack of oxygen. Also, this process is carried out by some types of bacteria. So, option (a) 'Some bacteria' is also correct.

Making the Final Selection

By comparing the choices again, we can eliminate option (d) 'Aerobic condition' as lactic acid fermentation does not happen in aerobic conditions. Therefore, the most accurate answer is option (c) 'Both (a) and (b)'. This option combines the other two correct choices, indicating that lactic acid fermentation can occur in both some bacteria and muscle cells during anaerobic conditions.

Key concepts

Anaerobic Conditions

Anaerobic conditions refer to environments where oxygen is not present. These settings are crucial for certain biological processes such as lactic acid fermentation. In the absence of oxygen, cells must find an alternative way to produce energy. This occurs through anaerobic respiration.
When there is a lack of sufficient oxygen, cells cannot proceed with aerobic respiration, which normally involves the complete breakdown of glucose into carbon dioxide and water. Instead, they resort to anaerobic pathways to ensure they still produce ATP, which is essential for cell survival. The result is usually less efficient as compared to aerobic processes but is vital when oxygen is scarce.
Lactic acid fermentation is a type of anaerobic respiration that converts glucose into lactic acid. This is especially important for cells that need a rapid energy supply without waiting for oxygen to arrive, such as muscle cells during intense exercise.

Muscle Cells

Muscle cells are specialized cells responsible for movement and force generation in the body. They have unique characteristics that allow them to contract and produce motion. During periods of intense physical exertion, the demand for energy exceeds the capacity of oxygen supply, triggering lactic acid fermentation.
This metabolic process in muscle cells allows them to generate a quick burst of energy despite limited oxygen availability. The conversion of glucose to lactic acid releases energy in the form of ATP, which can be used immediately by the muscle cells.
However, the downside is the accumulation of lactic acid, which can lead to muscle fatigue and soreness. Once the activity decreases and oxygen becomes available again, the lactic acid is often converted back to pyruvate and utilized in regular cellular respiration.

Bacteria Metabolism

Bacteria are diverse organisms with various metabolic capabilities. Some species can switch to lactic acid fermentation as part of their metabolic process, particularly under anaerobic conditions.
Lactic acid bacteria (LAB) are a group known for this ability. They are often used in food fermentation, such as in the production of yogurt, cheese, and pickles. These bacteria ferment sugars into lactic acid, which not only helps preserve the food by lowering its pH but also enhances its flavor.

• LAB can thrive without oxygen, effectively utilizing anaerobic conditions for energy production.
• The lactic acid they produce helps inhibit the growth of spoilage organisms, making them beneficial for both industrial and health applications.

Overall, the metabolic flexibility of bacteria allows them to adapt to various environments and contribute significantly to ecological and industrial processes.