The evolutionary order of metabolic types is heterotrophic anaerobic → autotrophic anaerobic → aerobic → chemical synthesis.
The metabolic type of primitive life is heterotrophic anaerobic, so is the metabolic type of single-celled prokaryotes evolved from primitive life. Single-celled prokaryotes ruled the earth for about 654.38+0.5 billion years. During the 654.38+0.5 billion years, most of the organic matter in the primitive ocean was exhausted, so that the content of organic matter in the primitive ocean became less and less, and the survival pressure of prokaryotes became greater and greater. Through mutation and selection, photoautotrophic prokaryotes gradually evolved. The earliest evolved photoautotrophs used inorganic or organic substances, such as H2S and isopropanol, as reducing agents to reduce CO2 to organic substances. This process is called bacterial photosynthesis. Because there was no oxygen on the earth when this kind of autotrophic prokaryote evolved, its alienation type was anaerobic. The existing red sulfur bacteria and red non-sulfur bacteria all belong to this type. Most of them are facultative anaerobic bacteria. The cells of photosynthetic bacteria have no chloroplasts, but spherical particles with double membranes, which are similar to thylakoids in chloroplasts and are called color carriers. The color carrier contains bacterial chlorophyll and carotenoids, which can absorb and transmit light energy for photosynthesis. Red sulfur bacteria use CO2 as carbon source, H2S or other sulfides as hydrogen source and electron donor for photosynthesis, and do not release oxygen. Red non-sulfur bacteria accumulating sulfur. CO2+2H2S-(CH2O)+2S+H2O can't use sulfides as hydrogen donors, but some organic substances (fatty acids, alcohols and methane) can be used as hydrogen donors and electron donors to reduce CO2. For example, Spirulina rubra uses isopropanol to reduce CO2 and form acetone sugar without releasing oxygen.
Although photosynthetic bacteria can produce organic matter by themselves, the number of hydrogen donors and electron donors (H2S, isopropanol, etc.). ) its use on the earth is limited, and it is impossible to evolve aerobic organisms without releasing oxygen. Therefore, this autotrophic type has no development prospect and cannot fundamentally change the face of the earth. Only by evolving photosynthetic organisms with water as hydrogen donor and electron donor can we fundamentally change the face of the earth. Because this type of photosynthesis can produce oxygen, and the water on the earth is abundant and can be recycled during metabolism. Therefore, water is almost inexhaustible as the raw material of photosynthesis. The dissimilation type of the earliest evolved photosynthetic organisms is still anaerobic. Aerobic organisms evolved after there was free oxygen on the earth. The metabolic efficiency of aerobic organisms is much higher than that of anaerobic organisms. Therefore, the speed of biological evolution is greatly accelerated. The metabolic pattern of chemical synthesis only appeared after the evolution of photosynthetic organisms, because the process of chemical synthesis needs oxygen, and the way of alienation is oxygen.
I. Types of assimilation
1, autotrophic
(1) photoautotrophic
Seed plants: poplar, willow, pine, cypress, etc.
Pteridophytes: Adiantum, Selaginella, Nephropterium, etc.
Bryophytes: liverworts and melons, etc.
Algae plants: cyanobacteria, Chlamydomonas, Spirogyra, kelp, laver, etc.
Photosynthetic bacteria: red sulfur bacteria, purple sulfur bacteria, green sulfur bacteria, etc.
For example, red sulfur bacteria use CO2 as carbon source, H2S or other sulfides as hydrogen source and electron donor, and carry out photosynthesis under illumination, instead of releasing oxygen, they accumulate sulfur. CO2+2H2S —(CH2O)+2S+H2O。
(2) chemoautotrophic type
Nitrifying bacteria, sulfur bacteria, iron bacteria and hydrogen bacteria.
For example, sulfide bacteria can utilize many sulfides in the environment (hydrogen sulfide, elemental sulfur, thiosulfate and iron sulfide, etc.). ) as an energy source for producing sulfuric acid. The reaction formula is as follows:
Sulfur bacteria absorb the energy released by the above reaction, and synthesize organic matter from carbon dioxide and water absorbed from the outside.
For another example, nitrite bacteria can oxidize ammonia in the environment into nitrite and release energy at the same time. Nitrogen-containing bacteria can oxidize nitrite into nitric acid and release energy at the same time. These two bacteria are oxidized one after another, and the released chemical energy is used to synthesize glucose from carbon dioxide and water ingested from the outside.
2. Heterotrophic type
(1) Predator type
Eagles, wolves, rabbits, mice, insects, etc.
(2) Parasitic type
Parasites on the body surface: lice, fleas, leeches, dodder, etc.
In vivo parasitism: Ascaris, Taenia solium, Schistosoma japonicum, Escherichia coli, Staphylococcus, Streptococcus, etc.
(3) saprophytic type
Vultures, dung beetles, maggots, earthworms, fungi (yeast, Penicillium, Aspergillus, mushrooms, fungus, Ganoderma lucidum, Hericium erinaceus), etc.
(4) Nitrogen-fixing bacteria: azotobacter chromosphere (born in * * *), rhizobia (saprophytic bacteria), etc.
3, facultative nutritional type
Spirulina, Venus flytrap, Nepenthes, etc.
Second, the types of alienation
1, aerobic type
(1) Eukaryotes
The vast majority of animals and plants, fungi (yeast, Penicillium, Aspergillus, mushrooms, fungus, Ganoderma lucidum, Hericium erinaceus) and so on.
(2) Prokaryotes
Chromospheric nitrogen-fixing bacteria, rhizobia, Corynebacterium glutamicum, Brevibacterium flavum, Acetobacter, Mycobacterium tuberculosis, Pseudomonas aeruginosa, Vibrio cholerae, etc.
2. Anaerobic
(1) Eukaryotes
Human ascaris, pork tapeworm, schistosomiasis, etc.
(2) Prokaryotes
Lactic acid bacteria, tetanus toxoid, denitrifying bacteria, red sulfur bacteria, purple sulfur bacteria and green sulfur bacteria.
3. facultative anaerobic type
Yeast, Escherichia coli, Rhodosporium, Staphylococcus, etc.