lab 10

Dimorphic fungi

-A member of the kingdom Fungi that can exist as either a mold or a yeast; display two growth patterns. -Many pathogenic fungi fall into the dimorphic category.

Parasitic helminths

-A member of the phylum Platyhelminth or Nematoda that require a host to survive -Dorso-ventrally flattened with an incomplete digestive tract that lacks an anus, meaning waste must be excreted back through the mouth -Flukes, tapeworms, flatworms, roundworms

Viruses

-Acellular obligate intracellular parasites that must hijack a living-host cell's enzymes in order to replicate -All organisms on Earth can be infected by viruses, from bacteria to plants to animals

Hookworms

-Another parasitic nematode that live in human intestines and have eggs that are passed via feces, contaminated soil, or contaminated water -The larvae hatch in the soil or water and feed on bacteria, then enter humans through the skin -Poorly cooked pork (worldwide) or wild game (US) is the source of Trichinella spiralis, the causative agent of trichinosis

Nematodes

-Cylindrical in shape, tapered at each end, and have a complete digestive system with both a mouth and an anus -Some can be found in soil and water samples, while others are found only in their host organism -Humans can be infected by either nematode eggs or larvae -Pinworms (Enterobius verminularis)complete their life cycle in humans. The eggs are the infective agent and can be passed between humans by exposure to contaminated clothes or bedding

Trophozoite stage

-Protozoa gather nutrients by consuming bacteria and other available particulates -Protozoans can propel themselves through the use of either flagella, cilia, or pseudopodia (false feet)

Penicillium

-Species within this genus (molds) perform an enormous range of functions, which are utilized by various industries. This includes the source of the antibiotic penicillin, giving certain cheeses distinctive flavors, in the production of some cured meats, and the production of antifungal and potentially chemotherapeutic agents. -Some cause food spoilage, and many produce toxins that can adversely affects humans and other animals.

Protozoa

-Unicellular chemoheterotrophic microorganisms that reside in water and soil -Typically have two life-cycle stages: trophozoite and cyst -All heterotrophs, some are also mixotrophs, getting energy through symbiotic relationships with autotrophs -Live in extremely harsh conditions; cyst allows the protozoan to survive until optimal conditions return -Most reproduce asexually, while some reproduce sexually (Paramecium species) -Organized on the basis of morphology: amoeba, flagellate, ciliate, and sporozoa

Flukes

-Unsegmented and have ventral and oral suckers that are used to attach to a host and absorb nutrients through their cuticle (outer covering) -Can cause disease in organs as a result of damage caused by their eggs, which can become embedded in the tissues -Tapeworms in the Taenia species (beef and pork tapeworms), and Hymenolepis nana (dwarf tapeworn)

Saccharomyces cerevisiae

-Used in bread, beer, and wine production. S. cerevisiae cells are also commonly used in microbiology labs as a mode organism due to their easy upkeep, low cost, and familiarity. -Scientists use what they've learned about yeasts and apply it to the human nervous system, cell division, drug testing, cancer, Parkinson's, and many genetic disorders. -Yeasts can potentially cause serious infections if they are allowed to overpopulate, as can often happen in immunocompromised individuals. /// candida albicans

Fungi are commonly grouped into three categories:

-Yeasts: unicellular, spherical or oval in shape, reproduce asexually through budding or binary fission; perform either aerobic respiration or fermentation. -Molds: multicellular fungi made up of individual microscopic filaments, called hyphae, that grow together to form a mycelium; hyphae can be either (septate) separated into individual cells by cell walls with small pores that allow the passage of nutrients among the cells, or they may be made up of one continuous cell (nonseptate or coenocytic) with multiple nuclei. -Mushrooms: filamentous fungi with macroscopic fruiting bodies that produce the reproductive spores.

Microscopic eukaryotes include:

-fungi -protozoans -algae -slime molds -lichens (mutualistic combinations of a fungus with an algae or cyanobacterium)

Macroscopic eukaryotes include:

-parasitic helminths (flatworms of the phylum platyhelminthes and round worms of the phylum Nematoda) that have microscopic life stages

Retroviruses

A family of RNA viruses that encode an enzyme called reverse transcriptase. This enzyme is used in conjunction with the host cellular machinery to transcribe the virus's single-stranded RNA into double-stranded DNA.

Nonenveloped Virus

A microscopic infectious agent that lacks a proteinaceous coat around its capsid.

Enveloped Virus

A microscopic infectious agent with a coat of phospholipids with embedded proteins derived from the host cell's membrane around its capsid.

Oncoviruses

Cause cancer through host oncogene activation and can be either DNA or RNA viruses. When oncoviral DNA integrates with the host cell's DNA, it alters the cell in a way that induces the cell to undergo abnormal growth.

Oncolytic Viruses

Exclusively infect cancerous cells, resulting in lyses of the cancer cells and can eventually result in the death of a tumor. Research is underway attempting to utilize oncolytic viruses as an effective cancer treatment.

Fungi structures

Include cell walls that can be distinguished from the cell walls of plants and animals in that they contain both glucans and chitins.