Microbio - CH 5

What is endosymbyosis?

1. cell engulfs a smaller cell

2. the engulfed cell survices

3. they live in symbyosis

4. the engulfed cell becomes a permanent resident

5. later passed to offspring

What organelles are a result of endosymbyosis?

mitochondria, chloroplasts, cilia, flagella, centrioles

cellularity of protozoa.

unicellular, few colonial

cellularity of fungi and algae.

may be unicellular, colonial, and multicellular

cellularity of helminths and arthropods.

multicellular except reproductive stages

What locomotor appendages has a 9+2 microtubule arrangement?

cilia and flagella

Describe flagella in eukaryotic cells.

10 times thicker than prokaryotic flagella, moves in a whiping motion, common in protozoa, algae. few fungi and animal cells have flagella

what protein makes up eukaryotic flagella

tubulin

How do cilia move?

power stroke or recovery stroke

Describe cilia.

very similar to flagella

shorter and more in number

only found in protozoa and animal cells

beat back and forth in a oarlike motion

function as feeding and filtering structure

describe glycocalyx (extracellular matrix)

an outermost boundry that comes into direct contact with the environment

usually composed of poly saccharides

appears as a network of fibers, a slime layer or capsule

How does a glycocalyx function

adherence, protection, and signal reception

What is beneath the glycocalyx

fungi and most algae have thick rigid cell wall surrounding the cell membrane

protozoa, a few algae, and all animal cells lack a cell wallo and have only a membrane

What eukaryotes have a cell wall

protozoa, algae, fungi

describe the cell wall in fungi.

have a thick inner layer of polysaccharide fibers composed of chitin or cellulose and a thin outer layer of mixed polysaccharides

describe the cell wall in algae.

varies in chemical compostition, substances commonly found include cellulose pectin, mannnans, silicon dioxide, and calcium carbonate.

describe the cell membrane.

phospholipid bilayer and proteins

sterols (cholesterols) confer stability

serve as selectively permeable barrier in transport

also function in interaction and surface adhesion, secretion, and signal transduction

describe the nucleus.

contains nuclear envelope (2 parallel membranes), nucleolus(dark area for rRNA synthesis and ribosome assembly), and chromosomes (in the nucleoplasm has histones and DNA)

define rough endoplasmic recticulum

originates from the outer membrane of the nuclear envelope and extends in a continuous network through cytoplasm; rough due to ribosomes; proteins synthesized and shunted into the ER for packaging and transports; first step in secretory pathway

describe the structure of smooth ER.

closed tubular network without ribosomes

what is the function of smooth ER

nutrient processing, synthesis, and storage of lipids

what are the stack of flattened sacs in the golgi called

cisternae

what is the function of the golgi.

modifies, stores, and packages proteins

describe ribosomes

compsed of rRNA and proteins, scattered or associated with the rough ER, 80s

what is the functions of ribosomes

protein synthesis.

describe the endomembrane system.

RER → transport vescicles → golgi apparatus → secretory vescicles

incoming vescicles → lysosomes → lysosomes mix with transport

describe the function of mitochondria

fucntion in energy production and storage (ATP)

what are cristae?

sperical organelle with an outer membrane and an inner membrane with folds

What does the cristae membranes contain?

the enzymes and electron carriers of aerobic respiration

Describe the division of mitochondria.

divide independently of the cell, DNA and prokaryotic ribosomes are contained in the spaces around the cristae called matrix.

Where are chloroplasts found?

algae and plant cells

what do chloroplasts do?

convert the energy of sunlight into chemical energy through photosynthesis. primary producers of organic nutrients for other organisms.

describe the membrane of chloroplasts.

outer membrane covers inner membrane folded into sacs called thylakoids, stacked into grana. They carry pigments (chlorophyll and others)

describe the cytoskeleton

flexible framework of proteins, microfliaments and microtubules form network through cytoplasm

what is the function of the cytoskeleton

involved in organelles anchoring, movement of cytoplasm, amoeboid motion, transport, and structural support

what is the cell wall of the fungi made of?

polysaccharide chitin

what does the cell membrane contains…

sterols such as ergosterol

how do fungal cells grow?

in loose associations or colonies

1. yeast colonies have soft, uniform texture and appearence

2. filamentous fungi have cottony, hairy, velvety texture

what are the oxygen requirements of fungi?

obligate aerobes, some are faculative anaerobes, few are obligate anaerobes.

What pH can fungi optimally grow at ?

acidic

what are the two groups of fungi?

macroscopic or microscopic

Describe microscopic fungi.

unicellular, usually yeasts, produces psuedohyphae, has a round oval shape

have a cell wall and lack locomotor organelles

How do microscopic fungi reproduce?

asexually

Define vegetative fungi.

digest and absorb nutrients

define reproductive hyphae.

produce spores for reproduction

Describe macroscopic fungi.

multicellular, molds, filamentous

where do you see psuedo hyphae in?

yeasts

how would you describe macroscopic hyphae?

septate hyphae or nonseptiate hyphae

What are the three ways of fungal reproduction.

fragmentation, asexually, sexually

Describe fragmentation reproduction.

piece of mycelium can create an entire colony, primary reproduction is spores

define asexual reproduction in fungi.

products of mitotic division from a single parent cell. Sporangiospores or conidia

what are sporangiospores?

asexual spores, are formed in sporangium (sac like structure)

what are conidia

asexual spores, free spores

define sexual reproduction in fungi

two different strain of hyphae form union to form spore, responsible for genetic variation, useful for fungal classification, 3 types (zygospores, ascospores, basidiospores)

How are fungi classified

by sexual spores

Describe zygomycota.

recognized by zygospores inside sporangia, mostly sporangiospores and some conidia, example is bread mold

describe ascomycota

a sac fungi, produce their ascospores in special pods (sac-like structures) called ascus, have conidia, examples like yeast, truffles, morels, cup fungi, flask fungi

describe basidiomycota.

a club fungi, basidiospores are produced on a club-like structure called a basidium, have conidia, examples like mushrooms and toadstools

How do imperfect fungi (deuteromycetes) reproduce?

by asexual spores

What do chytridiomycota have for spores?

flagellated spores

describe the role of fungi.

mostly free living (no dependent on host), even pathogenic

What do hyphae do?

grows into food for then fungus to eat

what do fungi tips do?

secrete powerful, extracellular enzymes

What are the adverse impacts of fungi?

mycoses (fungal INF), allergies, toxin production

destruction of crops and food storages

What are the beneficial impacts of funi?

sources of antibiotics, alcohol, organic acids, vitamins

decomposers of dead plants and animals

used in making foods and in genetic studies

What are superficial fungal infections called?

dermal mycoses caused by dermatophytes (cutaneous layer)

secrete enzymes called keratinase

digest hair, skin, and nails

What are some examples of dermal mycoses?

tineas, ringworm, jock itch, athelete’s foot

What is an appurtunistic fungi?

Candida albicans

dimorphic fungus, part of oral, GI, and vagina microbiome

How do systemic fungal infections spread?

they are deep, organism enters the lungs and invades other organs

How does fungal intoxication occur?

fungal chemical byprodcuts (NOT THE CELLS) enter the host and cause disease

Claviceps purpurea produces ergot poisioning and can like on grains

Aspergillus flavus produces aflatoxin which can live in nuts

Saccharomyces cerevisiae produces ethanol which can like in ethyl alcohol

What are examples of heterotrophs?

protozoans, chytrids, water molds, slime molds

What are examples of autotrophs?

algae, diatoms

What are both hetertrouphs and autotrophs?

euglenoids, dinoflagellates

What are the 2 kinds of protists?

algae (auto), protozoans (hetero)

define algae.

eukaryotic organisms, usually unicellular or colonial, that photosynthesize with chlorophyll a.

What are plankton?

community of floating microscopic organisms that provide the basis of food web in most aquatic habitats, they produce a large portion of atmospheric O2. live in fresh and marine water

What are the dangers of dinoflagellates?

can cuase red tides and give off toxins that cause food poisoning with nuerological symptoms, cooking does not kill the toxin

define protozoa.

unicellular eukaryotes that lack tissues and share similarities in cell structure, nutrition, life cycle, and biochemistry

what is ectoplasm?

involved with locomotion, feeding, and protection

what is endoplasm?

houses the nucleus, mitochondria, and food and contractiles vacuoles

How do protozoans feed?

engulfing microbes and organic matter

How do protozoans move?

flagella, cilia, pseudopods

What is a trophozoite?

active, feeding stage

what is a cyst (protozoan definition)?

dormantt, resting stage

can spread through the air, water, and contaminated food

what causes a cyst to become active again?

moisture and nutrients restored (Excystment)

What causes a trophozoite to be come dormant?

drying, unfavorable conditions, and lack of nutrients

How do protozoans reproduce?

asexually (mitotic division), or multiple fission inside a host cell

How are protozoans classified?

by their motile stuctures

How do mastigophora move?

flagella + flagella and amoeboid motion

How do mastigophora reproduce?

sexual (syngamy) or asexual (longitudinal fission)

Do mastigophora produce cysts?

yes, and are free-living, some are parasitic

what is the sturcture of mastigophora?

single nucleus, some lack mitochondria, and golgi apparatus

What are some examples of mastigophora?

trpanosoma, Leishmania, giardia, trichomonas

What do trypanosoma and leishmania do?

blood pathogens spread by insect vectors (T. brucei -african sleeping sickness, T.cruzi - chagas disease)

What does giardia do?

spreads through fecal contaminated food and water, it is an intestinal parasite

What does a trichomona do?

STI, spreads through sexual contact

What are the hosts and vectors of T. cruzi?

Hosts: mammalian (dogs, cats, opossums, armadillos)

Vactors: reduviid (kissing bug)

What is the transmission of T.cruzi?

reduviid bug bites mucous membranes (eyes, nose, lips)

bug poops on the bite, releases protozoan

What does the INF progession look like for T.cruzi?

1. trophozoites multiply in the muscles and WBC

2. INF cells rupture, releases more trophozoites into the bloodstream

3. trypanosomes spread to organs: lymphoid tissues, heart, liver, brain

What are the disease manifestations of T.cruzi?

early: fever, inflammation

severe: heart and brain damage

chronic: disease can persist for years and cause death