Question

Explain the three pathways of breakdown in living organisms.

Answer 1

Glucose three pathways - Glucose is first broken down to 3 carbon molecules called pyruvate. This process takes place in the cytoplasm of all organisms. Pyruvate is further broken down by the following steps -

1. In yeast :- Pyruvate is broken down in the absence of oxygen and the process is called anaerobic respiration. In yeasts, pyruvate is broken down to produce CO₂ and ethanol.

2. In Muscle Cells :- During rigorous physical activity, the energy demand of our muscle cells increases rapidly. This is compensated by anaerobic respiration in muscle cells. In muscle cells, pyruvate is broken down into lactic acid.

3. In Mitochondria :- In case of aerobic respiration (in presence of oxygen) pyruvate is broken down in mitochondria. Here Pyruvate is broken down to produce H₂O and CO₂. Aerobic respiration is most common in most  organisms.