Researchers discover a plant that does not need sunlight for growth they isolate a unique compound found in the plants roots the compound breaks down into amino acids and functions to break down organic matter into food for the plant. What type of compound did the researchers discover?

The compound described in the context given functions to break down organic matter into food for the plant, which indicates that it likely serves a role in digestion or metabolism. This is characteristic of enzymes, which are biological catalysts that facilitate biochemical reactions.

Given the options provided, the best answer is:

**D. Biological catalyst**

This suggests that the isolated compound is likely an enzyme that helps the plant break down organic matter into more accessible nutrients.