Photosynthesis, Monera, Protista, Fungi, Plantae, and Animalia Kingdoms
Photosynthesis
In the photosystems, [light energy] is used to form NADPH. In the electron transport chain, the energy of those electrons is used to form ATP. The dark phase occurs independently of light, without using chlorophyll. It takes place in the stroma, and it uses the energy (ATP and NADPH) of the light-dependent phase to fix carbon dioxide and obtain organic molecules. The carbon source is CO2, the source of nitrogen is nitrates and nitrites, and the source of sulfur is sulfates. All this is done by a closed cycle called the Calvin Cycle, which has three phases:
- Carboxylation phase
- Reduction phase
- Regeneration phase
Kingdom Monera (Bacteria)
Includes prokaryotic and unicellular beings such as cyanobacteria and bacteria. Bacteria have a peptidoglycan cell wall, very different from the cellulose cell wall of plants. Cell shapes found in bacteria are diverse: spherical (cocci), rod-shaped (bacilli), comma-shaped (vibrios), or spiral (spirilla). Their ecological role is varied. Although most are decomposers of plant and animal remains, some are involved in the biogeochemical cycles of certain elements like nitrogen. Others are photosynthetic, and many are employed in industrial processes because they are saprophytes. Cyanobacteria are photosynthetic and were very important in the formation of the oxidizing atmosphere due to their oxygen production.
Kingdom Protista (Plankton and Algae)
Includes protozoa and algae, which are microscopic beings. Protozoa are unicellular eukaryotes that depend on the environment in which they live for diffusion phenomena. Despite being unicellular, some possess complex structures and present two nuclei. They form part of the zooplankton. Their ecological function: some are parasites, such as amoebas. Others are symbiotic, such as those that live in the intestines of wood-eating insects like termites. Microscopic algae are difficult to differentiate from protozoa. They are also eukaryotic and have, in addition to chlorophyll, other pigments like phycocyanin (blue), phycoerythrin (red) or fucoxanthin (brown). Ecologically, they are producers in freshwater and marine ecosystems.
Kingdom Fungi
Fungi have no chlorophyll and are therefore not autotrophs; almost all have a cell wall of chitin. Their cells are eukaryotic and form filaments called hyphae. Hyphae intersect and result in a structure called mycelium, with a velvety appearance. The various mycelia develop in the substrate where they live saprophytically. The function of fungi is varied, but they are highlighted as decomposers. Some are parasites of animals or plants. From some molds, like *Penicillium*, we can obtain antibiotics and other chemical substances. Yeasts (another type of fungus) are used in bakeries to prepare bread and in wineries for the alcoholic fermentation process. Mushrooms are the fruiting bodies of the underground mycelium of many types of fungi.
Kingdom Plantae (Plants)
Plants are eukaryotic, multicellular beings. They possess cellulose cell walls, and photosynthesis abounds in their chloroplasts because they have chlorophyll. They develop reproductive organs. The ecological function of plants is vital for the biosphere, as life depends absolutely on primary producers. They capture light energy, transform it into chemical energy, release oxygen, and enrich the atmosphere.
Kingdom Animalia (Metazoa)
Animals are eukaryotic, multicellular, and heterotrophic beings. They develop tissues, organs, and very complex apparatuses and systems. They have the capacity for movement thanks to the coordinated action of the muscular and nervous systems. Their ecological function is that of the consumer; the group is differentiated into herbivores or primary consumers and carnivores or secondary consumers. Some are omnivores and scavengers.