Final answer:
Decay is the breakdown of dead tissues by microorganisms like bacteria, referred to as decomposers, which are essential for nutrient recycling in ecosystems.
Step-by-step explanation:
The breakdown of dead tissues that results from the activity of microorganisms, especially bacteria, is called decay. These microorganisms, known as decomposers, play a vital role in ecosystems by recycling nutrients back into the environment. Decomposers such as bacteria break down dead materials and waste products by using the organic substrates to get their energy, carbon, and nutrients necessary for their survival. They have the ability to degrade a wide variety of carbon sources, including carbohydrates, lipids, and proteins.
The catabolic pathways for these molecules eventually link into glycolysis and the Krebs cycle, essential processes for energy production in living organisms. For instance, triglycerides are degraded into fatty acids by extracellular lipases, while proteins are broken down into smaller peptides by extracellular proteases. These processes not only recycle nutrients but also form humus, which increases soil fertility, and provide nourishment to other living organisms in the ecosystem.