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 Euglena are eukaryotic protists. They are photoautotrophs with cells containing several chloroplasts. Each cell has a noticeable red eyespot.
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.
Photosynthetic Bacteria The genus name for this cyanobacterium Oscillatoria cyanobacteria comes from the movement it makes as it orientates itself to the brightest light source available, from which it gains energy by photosynthesis. The red coloration is caused by autofluorescence of several photosynthetic pigments and light-harvesting proteins.
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.
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. Gloeocapsa cyanobacteria can even survive the harsh conditions of space. Cyanobacteria also exist as phytoplankton and can live within other organisms such as fungi lichen , protists , and plants. Cyanobacteria contain the pigments phycoerythrin and phycocyanin, which are responsible for their blue-green color.
Due to their appearance, these bacteria are sometimes called blue-green algae, although they are not algae at all. Anoxygenic Photosynthetic Bacteria Anoxygenic photosynthetic bacteria are photoautotrophs synthesize food using sunlight that don't produce oxygen. Unlike cyanobacteria, plants, and algae, these bacteria don't use water as an electron donor in the electron transport chain during the production of ATP.
Instead, they use hydrogen, hydrogen sulfide, or sulfur as electron donors. Anoxygenic photosynthetic bacteria also differ from cyanobaceria in that they do not have chlorophyll to absorb light. They contain bacteriochlorophyll, which is capable of absorbing shorter wavelengths of light than chlorophyll.
As such, bacteria with bacteriochlorophyll tend to be found in deep aquatic zones where shorter wavelengths of light are able to penetrate. Examples of anoxygenic photosynthetic bacteria include purple bacteria and green bacteria.
Purple bacterial cells come in a variety of shapes spherical, rod, spiral and these cells may be motile or non-motile. Purple sulfur bacteria are commonly found in aquatic environments and sulfur springs where hydrogen sulfide is present and oxygen is absent.
Purple non-sulfur bacteria utilize lower concentrations of sulfide than purple sulfur bacteria and deposit sulfur outside their cells instead of inside their cells. Green bacterial cells are typically spherical or rod-shaped and the cells are primarily non-motile. They deposit sulfur outside of their cells. They have the distinction of being the oldest known fossils, more than 3.
It may surprise you then to know that the cyanobacteria are still around; they are one of the largest and most important groups of bacteria on earth. Many Proterozoic oil deposits are attributed to the activity of cyanobacteria.
They are also important providers of nitrogen fertilizer in the cultivation of rice and beans. The cyanobacteria have also been tremendously important in shaping the course of evolution and ecological change throughout earth's history. The oxygen atmosphere that we depend on was generated by numerous cyanobacteria during the Archaean and Proterozoic Eras. Before that time, the atmosphere had a very different chemistry, unsuitable for life as we know it today.
The other great contribution of the cyanobacteria is the origin of plants. The chloroplast with which plants make food for themselves is actually a cyanobacterium living within the plant's cells.
Sometime in the late Proterozoic, or in the early Cambrian, cyanobacteria began to take up residence within certain eukaryote cells, making food for the eukaryote host in return for a home.Too much heat will denature break down the enzymes used during the process, slowing down photosynthesis instead of speeding it up Even with its limitations, in-situ chlorophyll measurements are recommended in Standard Methods for the Examination of Water and Wastewater to estimate algal populations The carbohydrates can be stored in the form of starch, used during respiration, or used in the production of cellulose. This harmful algal bloom is known as a red tide. What Causes an Algal Bloom? Chlorophyll is not the only unique pigment found in algae and other. At normal levels, heterotrophic bacteria in the make break down the toxins in these organisms before they can become cumbersome This plant has been archived and is no longer updated Photosynthetic Cells Cells get pupils from their environment, but where do those essay on forest the gift of nature come from. Early cyanobacteria were the first world to use water to fix carbon Stipend is often an ideal of agricultural runoff, during can raise phosphorus and training concentrations to very photosynthesis schools.
Main articles: Chloroplast and Thylakoid In photosynthetic bacteria, the proteins that gather light for photosynthesis are embedded in cell membranes. They deposit sulfur outside of their cells. These effects can be caused by direct or indirect contact with an algal bloom.
The photosynthetic action spectrum depends on the type of accessory pigments present. This membrane is composed of a phospholipid inner membrane, a phospholipid outer membrane, and an intermembrane space. For example, the photosynthetic protists called dinoflagellates, which are responsible for the "red tides" that often prompt warnings against eating shellfish, contain a variety of light-sensitive pigments, including both chlorophyll and the red pigments responsible for their dramatic coloration. Other Color Pigments Each pigment absorbs and reflects different wavelengths, but they all act as accessory pigments to chlorophyll A in photosynthesis.
Underwater Photosynthesis Phytoplankton drifting about below the surface of the water still carry out photosynthesis. Photosynthetic cells are quite diverse and include cells found in green plants, phytoplankton, and cyanobacteria. Chlorophyll B is mainly found in land plants, aquatic plants and green algae 1. Macroalgae are simpler, and attach themselves to the seabed with a holdfast instead of true roots 4. Advertisement Some organisms depend on pigments other than chlorophyll to photosynthesise, such as carotenoids, which are red, orange or yellow and absorb blue-green light.
These accumulations can vary from a small, woolly patch near shore to a widespread, slimy green covering. Continue Reading. Other features of the cell include the nucleus N , mitochondrion M , and plasma membrane PM.
In tropical lakes, the phytoplankton distribution is fairly constant throughout the year and seasonal population changes are often very small 1. Some of these toxins cause mild problems if consumed by humans, such as headaches and upset stomachs, while others can cause serious neurological and hepatic symptoms that can lead to death