1, autotroph: an organism that can synthesize its own organic matter from inorganic matter belongs to autotroph. Such as cyanobacteria, nitrifying bacteria and green plants.

2. heterotrophs: Organisms that can only ingest ready-made organic matter from outside belong to heterotrophs. Such as most animals and fungi.

2. Alienation refers to the process that an organism decomposes its own organic matter into inorganic matter and returns it to the inorganic environment to release energy. The types of alienation include aerobic, anaerobic and facultative anaerobic.

1, aerobic type

Most animals and plants need to live in an oxygen-rich environment. In the process of alienation, they must constantly absorb oxygen from the external environment to oxidize and decompose the organic matter in their bodies and release energy to maintain their own life activities. This metabolic type is called aerobic type, also called aerobic respiration type.

2. Anaerobic

Such organisms include some animals, such as lactic acid bacteria and parasites that live in animals. In the absence of oxygen, they can still oxidize the organic matter in the body and obtain the energy needed to maintain their own life activities. This type of metabolism is called anaerobic, also known as anaerobic respiration.

3. facultative anaerobic type

This organism carries out aerobic respiration under the condition of sufficient oxygen, completely decomposes organic matter into carbon dioxide and water, and incompletely decomposes organic matter into lactic acid or alcohol and water under the condition of lack of oxygen. A typical facultative anaerobic organism is yeast.

Metabolic function

1, get nutrients from the external environment, get material and energy;

2. Convert substances obtained through external intake into their own components;

3. Assemble structural elements into their own macromolecules, such as protein, nucleic acids and lipids;

4. Decomposition of organic nutrients;

5. Provide all energy for the life activities of organisms.