How does protist get energy

Notice how the Paramecium is dividing into two cells. This, obviously, is a form of asexual reproduction. But, remember that protists are an extremely diverse kingdom, and some protists can also reproduce sexually.

Like all other eukaryotes, protists have a nucleus containing their DNA. They also have other membrane-bound organelles, such as mitochondria and the endoplasmic reticulum.

Most protists are single-celled. Some are multicellular. Because the protist kingdom is so diverse, their ways of getting food and reproducing vary widely. Most protists are aquatic organisms. They need a moist environment to survive. They are found mainly in damp soil, marshes, puddles, lakes, and the ocean. Some protists are free-living organisms. Others are involved in symbiotic relationships.

They live in or on other organisms, including humans. A pathogen is anything that causes disease. Parasites live in or on an organism and harm that organism. A significant number of protists are pathogenic parasites that must infect other organisms to survive and propagate. Protist parasites include the causative agents of malaria, African sleeping sickness, and waterborne gastroenteritis in humans.

Members of the genus Plasmodium must colonize both a mosquito and a vertebrate to complete their life cycle. In vertebrates, the parasite develops in liver cells and goes on to infect red blood cells, bursting from and destroying the blood cells with each asexual replication cycle. Of the four Plasmodium species known to infect humans, P. In , it was estimated that malaria caused between one and one-half million deaths, mostly in African children. During the course of malaria, P.

In response to waste products released as the parasites burst from infected blood cells, the host immune system mounts a massive inflammatory response with episodes of delirium-inducing fever as parasites lyse red blood cells, spilling parasitic waste into the bloodstream. Techniques to kill, sterilize, or avoid exposure to this highly-aggressive mosquito species are crucial to malaria control.

Red blood cells are shown to be infected with P. Trypanosoma brucei , the parasite that is responsible for African sleeping sickness, confounds the human immune system by changing its thick layer of surface glycoproteins with each infectious cycle.

The glycoproteins are identified by the immune system as foreign antigens and a specific antibody defense is mounted against the parasite. However, T. In this way, T. Without treatment, T. During epidemic periods, mortality from the disease can be high. Greater surveillance and control measures lead to a reduction in reported cases; some of the lowest numbers reported in 50 years fewer than 10, cases in all of sub-Saharan Africa have happened since Trypanosomes : Trypanosomes are shown among red blood cells.

In Latin America, another species, T. The parasite inhabits heart and digestive system tissues in the chronic phase of infection, leading to malnutrition and heart failure due to abnormal heart rhythms. They can do this in a few ways. Endocytosis , also called phagocytosis , is perhaps the most common method for heterotrophic protists. This is when animal-like protists physically engulf or "swallow" their prey. Amoebas, for example, are animal-like protists that engulf their prey and break them down inside their cell in order to get their nutrition.

These types of protists are also called phagotrophs. Other animal-like protists are filter feeders. They'll often use their flagellum to whip back and forth and create a flow or a current around them to filter through and absorb food from their environment.

This type of heterotroph is also called an osmotroph , which means they absorb food to eat from the environment instead of engulfing it whole like a phagotroph. Plant-like protists are autotrophs. Plant-like protists have chloroplasts in their cells in order to perform photosynthesis in order to convert sunlight into food aka glucose. Common plant-like photosynthetic protista examples include microscopic algae as well as huge multicellular seaweeds like kelp.

Fungi-like protists are also called mold. The two major types of fungi-like protists can be divided into water molds and slime molds. During epidemic periods, mortality from the disease can be high. Greater surveillance and control measures have led to a reduction in reported cases; some of the lowest numbers reported in 50 years fewer than 10, cases in all of sub-Saharan Africa have happened since In Latin America, another species in the genus, T.

The parasite inhabits heart and digestive system tissues in the chronic phase of infection, leading to malnutrition and heart failure caused by abnormal heart rhythms. An estimated 10 million people are infected with Chagas disease, which caused 10, deaths in Protist parasites of terrestrial plants include agents that destroy food crops.

The oomycete Plasmopara viticola parasitizes grape plants, causing a disease called downy mildew [Figure 6] a. Grape plants infected with P. The spread of downy mildew caused the near collapse of the French wine industry in the nineteenth century. Phytophthora infestans is an oomycete responsible for potato late blight, which causes potato stalks and stems to decay into black slime [Figure 6] b. Widespread potato blight caused by P. Late blight continues to plague potato crops in certain parts of the United States and Russia, wiping out as much as 70 percent of crops when no pesticides are applied.

They are equally important on the other end of food webs as decomposers. Protists are essential sources of nutrition for many other organisms. In some cases, as in plankton, protists are consumed directly. Alternatively, photosynthetic protists serve as producers of nutrition for other organisms by carbon fixation.

For instance, photosynthetic dinoflagellates called zooxanthellae pass on most of their energy to the coral polyps that house them [Figure 7]. In this mutually beneficial relationship, the polyps provide a protective environment and nutrients for the zooxanthellae.

The polyps secrete the calcium carbonate that builds coral reefs. Without dinoflagellate symbionts, corals lose algal pigments in a process called coral bleaching, and they eventually die. This explains why reef-building corals do not reside in waters deeper than 20 meters: Not enough light reaches those depths for dinoflagellates to photosynthesize. Protists themselves and their products of photosynthesis are essential—directly or indirectly—to the survival of organisms ranging from bacteria to mammals.

On land, terrestrial plants serve as primary producers. Protists do not create food sources only for sea-dwelling organisms. For instance, certain anaerobic species exist in the digestive tracts of termites and wood-eating cockroaches, where they contribute to digesting cellulose ingested by these insects as they bore through wood. The actual enzyme used to digest the cellulose is actually produced by bacteria living within the protist cells.

The termite provides the food source to the protist and its bacteria, and the protist and bacteria provide nutrients to the termite by breaking down the cellulose. Many fungus-like protists are saprobes , organisms that feed on dead organisms or the waste matter produced by organisms saprophyte is an equivalent term , and are specialized to absorb nutrients from nonliving organic matter.

For instance, many types of oomycetes grow on dead animals or algae.