Ho do organs compare to organ system

An organ is a system of tissues, while an organ system is a system of multiple organs.

The smallest to largest things in our body goes:
Cells, tissues, organs, organ systems.
Organs make up organ systems.

A. A Catalyst is defined as speeding up a chemical reaction, and breaking Hydrogen Peroxide apart chemically is a chemical reaction which abides by allowing a catalyst being present to speed up the reaction. Reactions occur faster with a catalyst because they require less activation energy