Exam 2 Chapter 12 The Eukaryotes: Fungi, Algae, Protozoa, and Helminth

Plantea (Plants)

(Eukayortic- all multicellular). The Kingdom { } includes some algae and all mosses, ferns, conifers, and flowering plants. To obtain energy, it uses photosynthesis, the process that converts carbon dioxide and water into organic molecules used by the cell. Has cellulose cell walls.

Animalia (Animals)

(Eukayortic- all multicellular). The Kingdom { } includes sponges, various worms, insects, and animals with backbones (vertebrates). They obtain nutrients and energy by ingesting organic matter through a mouth of some kind. Lacks cell walls.

Explain the mode of action of currently used antifungal drugs and relate them to the fungal cell structure.

- Some of the most common work by disrupting the cell membrane by targeting the synthesis of the sterol ergosterol. ● Azoles like Miconazole and Ketoconazole ● Allylamines are new and useful against strains resistant to the other antifungals. ●Ergosterol is a sterol found in cell membranes of fungi and protozoa, serving many of the same functions that cholesterol serves in animal cells. Because many fungi and protozoa cannot survive without ergosterol,the enzymes that create it have become important targets for drug discovery.

List the distinguishing characteristics of parasitic helminths

-Parasitic flatworms belong to the Phylum Platyhelminthes, and parasitic roundworms belong to the Phylum Nematoda. -Animilia Kingdom -Chemoheterotrohpic -multicellular -have eukaryotic cells -many are parasitic -they are heterotrophic -Some have male and female reproductive organs in one animal.

Fungi

1. Organism that belongs to Kingdom { }, & eukayortic. 2. Unicellular yeasts, multicellular molds, & macroscopic species such as mushrooms. To obtain raw materials for vital functions, "it" absorbs dissolved organic matter through its plasma membrane. The cells of a multicellular { } are commonly joined to form thin tubes- hyphae- which are usually divided into multinucleated units by cross-walls that have holes, so cytoplasm can flow between the cell-like units. { } develop from spores or from fragments of hyphae.

Define arthropod vector.

Arthropods that serve as vectors include mosquitoes, fleas, sand flies, lice, ticks, and mites. ... The arthropods feed on the blood which typically allows parasites to enter the bloodstream of the host. The Anopheles mosquito serves as a vector for malaria, filariasis, and arboviruses as well (arthropod-borne-viruses).

Dinoflagellates

Cellulose in plasma membrane Unicellular Chlorophyll a and c, carotene, xanthins Store starch Some are symbionts in marine animals (corals) Neurotoxins cause paralytic shellfish poisoning

more superficial mycoses

Conditions which favor dermatophyte infection - Frequent wetting of the skin - Oily skin - Close cropping of hair (that gets irritated with clothing) - Tightly fitting, poorly ventilated clothing - Obesity

Medically Important Phyla of Protozoa

Diplomonads Parabasalids Euglenozoa Amebae (Rhizopoda) Apicomplexa Dinoflagellates Ciliates

Describe the modes of actions of currently used antiprotozoan drugs and describe their side effects

Diseases caused by infections of protista are often difficult to treat and there are few drugs available. ● Antimalarial drugs include quinine, chloroquine, and some new drugs (some with psychiatric side effects). ● Idoquinol is one used for intestinal infections, but we don't even know how it works and it can cause blindness. ● Flagyl interferes with anaerobic metabolism and is effective against some protista and anaerobic bacteria.

Describe the ways in which fungi can act as allergens or cause intoxications.

Fungi as Allergens ● One of the most common types of allergens ● 20‐30% of the population develops some type of allergy ● Fungal spores do not survive in the body, but are destroyed by the immune system ● The allergic response is basically an over‐aggressive immune response which results in: ● Inflammation of the conjunctiva and the mucous membranes and itching. ● Asthma and difficulty breathing

List the major characteristics used to differentiate the three kingdoms of MULTICELLULAR Eukarya

Fungi, plants, and animals make up the three kingdoms of more complex eukaryotic organisms, most of which are multicellular.

Apicomplexa

Group of non‐motile (at least as adults) intracellular parasites Special organelles at the tips of the cells contain enzymes which allow the cells to penetrate the host's tissues Often have complex life cycles which involve several different hosts Examples include Plasmodium spp. which causes malaria, Cryptosporidium which is a water borne illness, and Toxoplasma gondii which causes toxoplasmo

Protista

In 1969, simple eukaryotic organisms, mostly unicellular, were grouped as the Kingdom { }, a catchall kingdom for a variety of organisms. Historically, eukaryotic organisms that didn't fit into other kingdoms were placed in the { }.

intermediate mycoses

Intermediate infections are those which occur in the skin, subcutaneous tissues, lungs, or mucous membranes, but typically will not spread to other tissues of the body

primary source of infection with members of the protista

Many protists exist as parasites that infect and cause diseases in their hosts.

Euglenozoa

Move by flagella Euglenoids Photoautotrophs Hemoflagellates Trypanosoma spp. Sleeping sickness Chagas' disease

Rhizopoda

amoebas that move by extensions of their body called psuedopodia, psuedopodia circle food and absorb it through phagocytosis

yeast

any unicellular fungus that reproduces vegetatively by budding or fission, including forms such as candida that can cause disease. and are capable of converting sugar into alcohol and carbon dioxide.

Dimorphic fungi

are fungi which can exist as mold/hyphal/filamentous form or as yeast. An example is Penicillium marneffei: At room temperature, it grows as a mold. At body temperature, it grows as a yeast.

hyphae

is a long, branching filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Yeasts are unicellular fungi that do not grow as hyphae.

Differentiate between an intermediate host and a definitive host.

● Definitive hosts are the hosts on which sexual reproduction of the parasite occurs. In plant pathology this is the primary host. ● Intermediate hosts are hosts on which only the juvenile form or asexual reproduction of the parasite occurs. In plant pathology this is the alternate host.

superficial mycoses

● Fungi attack the skin, hair, nails, or feathers (often call these fungi dermatophytes). - Nearly all of them are mycelial - Confined to superficial tissues - Frequency and severity of superficial diseases are influenced by local climate - Common in soil and may also be passed from person to person by direct contact - Examples: Athlete's foot and ringw

Explain the modes of actions of currently used antihelminthic drugs.

● There are a number of drugs available to treat infection with helminths: - Mebendazole and albendazole interefere with nutrient absorption and are used to treat intestinal infections. - Niclosamide interferes with anaerobic metabolism and helminths in the digestive tract are usually under anaerobic conditions. - Praziquantel causes worms to undergo muscle spasms and apparently makes the worms more easy for your immune system to

systemic mycoses

● Very often enter the host via the respiratory tract as spores - Initial symptoms are similar to tuberculosis ● Dry cough, nodule or cavity formation in tissue - May then spread to other organs including the brain ● Many also enter through various types of superficial wounds and disseminate to lymph nodes and other internal organs

List the defining characteristics of fungi and separate fungi from other organisms.

●Kingdom- Fungi ●Nutritional Type -Chemoheterotroph ●Multicellularity- All, except yeasts ●Cellular Arrangement -Unicellular, filamentous, fleshy ●Food Acquisition Method- Absorptive, extra‐cellular ●Characteristic Features Sexual and asexual spores ●Mycology: the study of fungi

List the characteristics of the three groups of parasitic helminths, and give an example of each.

●Phylum: Platyhelminthes (flatworms) -Class: Trematoda (flukes) -Class: Cestoda (tapeworms) ●Phylum: Nematoda (roundworms)can reside in the gastrointestinal tract, blood, lymphatic system or subcutaneous tissues. ●Thorny-headed worms (acanthocephalins) - the adult forms of these worms reside in the gastrointestinal tract.

A mycosis

●is a disease of a person or animal causedby a fungus. Names of diseases typically end in ‐osis or -mycosis. Examples: ●Sporotrichosis caused by Sporotrichum schenckii ● Coccidiomycosis caused by Coccidioides immitis ●Most people will have a disease caused by a fungus during their lifetime (yeast infection, athlete's foot, ringworm etc.), but deaths