What type of organisms undergo photosynthesis

What about desserts and drinks? All of these products contain sugar—the basic carbohydrate molecule produced directly from photosynthesis.

The photosynthesis connection applies to every meal and every food a person consumes. Photosynthesis requires sunlight, carbon dioxide, and water as starting reactants Figure 5. After the process is complete, photosynthesis releases oxygen and produces carbohydrate molecules, most commonly glucose.

These sugar molecules contain the energy that living things need to survive. The complex reactions of photosynthesis can be summarized by the chemical equation shown in Figure 5. Although the equation looks simple, the many steps that take place during photosynthesis are actually quite complex, as in the way that the reaction summarizing cellular respiration represented many individual reactions.

Before learning the details of how photoautotrophs turn sunlight into food, it is important to become familiar with the physical structures involved. In plants, photosynthesis takes place primarily in leaves, which consist of many layers of cells and have differentiated top and bottom sides. The process of photosynthesis occurs not on the surface layers of the leaf, but rather in a middle layer called the mesophyll Figure 5.

The gas exchange of carbon dioxide and oxygen occurs through small, regulated openings called stomata. In all autotrophic eukaryotes, photosynthesis takes place inside an organelle called a chloroplast. In plants, chloroplast-containing cells exist in the mesophyll. Chloroplasts have a double inner and outer membrane. Within the chloroplast is a third membrane that forms stacked, disc-shaped structures called thylakoids.

Embedded in the thylakoid membrane are molecules of chlorophyll, a pigment a molecule that absorbs light through which the entire process of photosynthesis begins. Chlorophyll is responsible for the green color of plants. The thylakoid membrane encloses an internal space called the thylakoid space. Other types of pigments are also involved in photosynthesis, but chlorophyll is by far the most important.

As shown in Figure 5. On a hot, dry day, plants close their stomata to conserve water. What impact will this have on photosynthesis? Photosynthesis takes place in two stages: the light-dependent reactions and the Calvin cycle. Carbon dioxide is converted to carbohydrates in a process known as carbon fixation or the Calvin cycle.

The carbohydrates can be stored in the form of starch, used during respiration, or used in the production of cellulose. Oxygen that is produced in the process is released into the atmosphere through pores in the plant leaves known as stomata.

Plants play an important role in the cycle of nutrients, specifically carbon and oxygen. Aquatic plants and land plants flowering plants , mosses, and ferns help to regulate atmospheric carbon by removing carbon dioxide from the air.

Plants are also important for the production of oxygen, which is released into the air as a valuable by-product of photosynthesis. Algae are eukaryotic organisms that have characteristics of both plants and animals. Like animals, algae are capable of feeding on organic material in their environment. Some algae also contain organelles and structures found in animals cells, such as flagella and centrioles.

Like plants, algae contain photosynthetic organelles called chloroplasts. Chloroplasts contain chlorophyll, a green pigment which absorbs light energy for photosynthesis. Algae also contain other photosynthetic pigments such as carotenoids and phycobilins. Algae can be unicellular or can exist as large multicellular species. They live in various habitats including salt and freshwater aquatic environments , wet soil, or on moist rocks.

Photosynthetic algae known as phytoplankton are found in both marine and freshwater environments. Most marine phytoplankton are composed of diatoms and dinoflagellates. Most freshwater phytoplankton are composed of green algae and cyanobacteria. Phytoplankton float near the surface of the water in order to have better access to sunlight needed for photosynthesis.

Photosynthetic algae are vital to the global cycle of nutrients such as carbon and oxygen. They remove carbon dioxide from the atmosphere and generate over half of the global oxygen supply. Euglena are unicellular protists in the genus Euglena. These organisms were classified in the phylum Euglenophyta with algae due to their photosynthetic ability. Scientists now believe that they are not algae but have gained their photosynthetic capabilities through an endosymbiotic relationship with green algae.

As such, Euglena have been placed in the phylum Euglenozoa. Cyanobacteria are oxygenic photosynthetic bacteria. They harvest the sun's energy, absorb carbon dioxide, and emit oxygen. Like plants and algae, cyanobacteria contain chlorophyll and convert carbon dioxide to sugar through carbon fixation. Unlike eukaryotic plants and algae, cyanobacteria are prokaryotic organisms. They lack a membrane bound nucleus , chloroplasts , and other organelles found in plants and algae.

Instead, cyanobacteria have a double outer cell membrane and folded inner thylakoid membranes that are used in photosynthesis.

Cyanobacteria are also capable of nitrogen fixation, a process by which atmospheric nitrogen is converted to ammonia, nitrite, and nitrate. These substances are absorbed by plants to synthesis biological compounds. Cyanobacteria are found in various land biomes and aquatic environments. Some are considered extremophiles because they live in extremely harsh environments such as hotsprings and hypersaline bays.

While many animals eat photosynthetic creatures, only a few can photosynthesize. Sea slugs steal the genes that allow algae to photosynthesize as they eat them and pass on the algal cells to their offspring. Spotted salamanders have a similar relationship with algae, although as a vertebrate, it is particularly special because most creatures with spines have immune systems that tend to kill foreign bodies such as algae. Some scientists theorize that Oriental hornets may draw energy from sunlight, although this doesn't appear to be photosynthesis proper.

Other researchers theorize that photosynthesis rarely evolved in animals for several reasons: Exposure to heat and ultraviolet light can be dangerous; the need for large surface areas conflicts with other survival strategies in animals; and there are health concerns associated with sugar-rich diets. The Morphology of Algae. What Plants Live in the Deep Ocean? Ecological Importance of Algae. What Do Volvox Eat? List of Underwater Ocean Plants.

Role of Algae in the Ecosystem. How Do Bacteria Respire? What Are Good Protists? Roles of Cyanobacteria in the Ecosystem.