IB Environmental systems and societies 2.2D Food Chain and Energy Loss Key Definitions

Cellular respiration is the conversion of stored chemical energy in glucose into a usable chemical form that fuels metabolic processes in living cells.

Consumers are organisms that obtain energy by feeding on other organisms.

Decomposers, such as fungi and bacteria, are organisms that break down organic matter into simpler substances.

Ecological efficiency refers to the percentage of energy that is transferred from one trophic level to the next in an ecosystem.

A food chain is a linear sequence that shows how organic matter and energy flow from one organism to another.

Producers, also known as autotrophs, are organisms that can produce their own food using photosynthesis (or chemosynthesis in some cases).

The Second Law of Thermodynamics states that in any energy transformation, some of the energy is lost as heat and becomes less available to do useful work.

A trophic level is the feeding position of an organism within a food chain or web, based on how it obtains its energy and nutrients.