EXAM 1 Chapter 11, Protozoan Groups Flashcards
Protozoan groups belong to the kingdom _____ and the phylum _____
Kingdom Protista
Phyla Protozoa
Phyla Protozoa characteristics..
- most unicellular
- organelles
- free-living, mutualists, or parasites (don’t live in a colony, live by themselves, or some live with others, and others feed off them
- aquatic to terrestrial
- asexual or sexual reproduction
Their locomotion involves
cilia and flagella
Cilia are
short, many in number
flagella are
single or small numbers, longer
cilia move by…
performing power stroke and then a recovery stroke
flagella…
are undulates, they move back and forth to move forward
but some also pull organisms like propeller
…..covered in cilia
trachea, bronchi, bronchioles of respiratory system
Primary ciliary dyskinesia (PCD)
- rare genetic lung disorder
- also known as Immotile Cilia Syndrome
- symptom - chronic respiratory tract infections
Cystic Fibrosis (CF)
mucus collects in airway and cannot move mucus and gets clogged
- genetic disorder, affected lungs most critically, also pancreas, liver, intestine
- characterized by thick, viscous secretions in the bronchi which cannot be transported by cilia to the pharynx
- bacteria thrive in the altered mucus, which collects in small airways of lungs
- leads to formation of bacterial microenvironments known as biofilms that are difficult for immune cells and antibiotics to penetrate
- most people with CF dont live past 30
Chronic obstructive pulmonary disease (COPD)
its because of scarring of tissue in lungs, not because of cilia
two main categories of COPD are
emphysema and chronic bronchitis
emphysema
walls of alveoli are damaged (gas exchange is reduced)
chronic bronchitis
- lining of airways constantly irritated and inflamed
- causes lining to thicken (excess mucus) meaning reduced diameter of tubes in respiratory system, which means its hard to breathe
main cause of chronic bronchitis
smoking
cilia and flagella have…
the same internal structure
the structure includes
- 9 peripheral doublets with 2 central singlets (all MICROTUBULES)
- doublets are linked by nexin
- dynein arms between each doublet
- dynein arms have ATPase (generation of ATP)
- doublets linked to singlets via radial spokes
the dynein arms
- are club like structures
- inner and outer dynein
- splits ATP and uses the energy
- doublets almost climb up using dynein arms
- grabs/binds to doublets in front of it, reach up, grab and pull and this causes bending/swaying motion of cilia
the doublets..
climb up/slide past each other’s back using the dynein arms
the sliding action..
translated to bending via nexin and radial spokes
nexin…
-causes it to bend, essential
- it connects one doublets to the others
- if nexin is broken, would elongate but not bend
another type of locomotion used by some is..
pseudopodia (false feet)
two types of pseudopods are
- lobopodia (blunt extension)
- axopodia (thin extension)
in an amoeba (lobopodia), there is a
endoplasm (fluid)
ectoplasm (gel, appears transparent
Actin filaments are..
bound in the ectoplasm, unbound in the endoplasm
When an amoeba wants to move…
- the endoplasm with action filaments is bound to regulatory proteins (so that they don’t bind to each other and become gel-like and not fluid)
- then the lipids in the membrane frees actin from regulatory protein
- Actin assembles and cross link (forms ectoplasm tube through which endoplasm flows
- Ca2+ triggers actin severing proteins and initiates interaction w/ myosin (contracts rear of organism, like squeezing tube of toothpaste from the back
- disassembled actin units bind w/ reg. protein and are recycled
Myosin is
-another movement molecules (similar to dynein arms)
- when it contracts causes back of organism to contract to help movement
endoplasm….
ectoplasm…
endo = actin monomers bound to regulatory proteins
ecto = actin filaments cross linked by actin binding proteins (ecto all around)
membrane in front
bulges due to Brownian motion (random movement of molecules due to kinetic energy in the form of heat)
after membrane bulges..
actin monomers lose regulatory protein due to lipids in membrane, polymerize (form actin filaments) and get added to front sections of ectoplasm via actin binding proteins
While the ectoplasm is getting assembled in front, in the rear of amoeba,
actin filaments in ectoplasm get disassembled and interact with myosin, contract and pull rear of membrane inward pushing endoplasm forward, Ca2+ ions initiate contraction
This whole process continues with…
more ectoplasm disassembly in the rear which then gets recycled and moved forward as endoplasm
2nd type of pseudopod is
axopodia (thin extensions supported by microtubules)
- there is still ecto and endo, but supported but long rods of microtubules
- can capture and eat things with these
- can extent and contract arms (deconstruct and grow)
How organisms expel waste
- pretty simple, diffusion
- just diffuse them out because waste wants to move from area of high to low concentration, so will naturally go out of cell
How organism regulates salt and water
- salt cannot move across membrane and water is going to go where greatest amount of solutes are present
- they use contractile vacuoles
- these are used to expel excess water (and salt)
there are more contractile vacuoles in freshwater vs. saltwater because
- in freshwater, there is a lot of water in environment and not a lot of salt
- in protozoa, in relation to freshwater have higher concentration of salts and lower concentration of water
- since salt cannot easily diffuse, the water outside naturally diffuses in and can cause them to burst, so need more CV
some species of CV contain
feeder canals and ampullae
there is usually an excretory pore..
which connects CV to cell wall of organism
- as it fills, excretory pole opens and expels water out
feeder canals
- most have an oral groove, rotate and this groove picks up food and then food goes to food vacuole, and then any waste also removed through CV
Since the water wants to come in, how do you get it out?
- since its all diffusion and osmosis, must have something to attract the water out
- ACTIVELY transports hydrogen ions inside into CV, since positively charged also attract (-) ions like bicarbonate in as well
- since these ions are being pumped in, water is attracted to these and PASSIVELY diffuses into CV
- sometime the CV will open and all water AND IONS will get expelled
exocytosis
process of releasing something out of cell
Two types of organisms that get nutrition differently
autotrophs (self feeder, makes own food)
heterotrophs (other feeder)
Under heterotrophs there are…
phagotrophs (take in particles) (phagocytosis)
- these surround and engulf food, breaks down food inside
osmotrophs (take in already dissolved matter)(pinocytosis)
- don’t engulf large, but incorporate small particles through cell membrane
many species can…
do both (auto and hetero)
for example Euglena
are autotrophs when there is light, and then when it is dark, osmotroph
phagocytosis
when they surround and engulf food
phagosome and lysosome involved in intracellular digestion
some protozoa have a mouth called
cytostome
most protozoa can be both…
sexual and asexual repro.
asexual reproduction called
fission
types of fission (asexual) include
- binary (fission)
- budding
- multiple fission
during binary fission
- creates copy of nucleus/DNA
- separates cytoplasm into equal amounts
- copies body and then peels apart and makes clone of itself
budding
- large adult organism will create a little pocket and it will copy DNA and send it into pocket
- this pocket becomes daughter colony or daughter cell
- it is a SMALLER (not equal division)
multiple fission also called
schizogony
Multiple fission
- binary is one to two
- this is where one separates into few/many
- single breaks up its DNA/body into multiple pieces and each of these become another organism
for sexual reproduction
must have diploid organism to be able to separate into haploid gametes
The dominant stage…
is sometimes haploid, sometimes diploid
If dominant is diploid
- then only must form gametes through meiosis
- these haploid gametes then fertilize and forms diploid zygote
- zygote first cells of new organism
if dominant is haploid
- create gametes via mitosis
- release these haploid gametes that are genetic copies of the parent, and these fertilize
- this produces diploid zygote which then undergoes meiosis to form haploid organisms
- then have asexual reproduction to form a larger haploid dominant organism
Cysts
- dormant form of protozoa with resistant covering and lowered metabolism
- way for it to survive very harsh conditions
- the protozoa form a cyst to survive winter, temp, toxic, etc
these cyst have
- resistant covering
- reduce their metabolism (not using a lot of energy)
encyst
- when they are in unfavorable conditions they make the cyst
excyst
- when conditions become favorable again, they break out of this covering
example of this is
entamoeba histolytica
- disease in less developed countries
- causes amoebic dysentery, or severe diarrhea
- you lose so much fluid, can be fatal to kids
in Phylum Euglenozoa is…which…
- microtubules under cell membrane stiffen it (pellicle)
- Under this phyla is organism called trypanosoma brucei and Euglena
trypano:
- invades nervous system and causes african sleeping sickness
- tsetse fly is vector, wild antelope is the reservoir (meaning antelope is host but not affected
- fly bites antelope then botes humans
- fall asleep during the day, cannot sleep at night, leads to death
Phylum Diplomonada
- lack mitochondria, golgi bodies
- Giardia lamblia - organism that causes severe diarrhea, called GIARDIASIS (beaver fever)
- organelles in pairs (2 nuclei), bilateral symmetry, money face
- giardia protected by outer shell that allows it to survive outside body for a long time and makes it tolerant to chlorine disinfection
- it cant produce energy, so absorbs nutrients directly through membrane (already broken down)
- beaver is the resevoir,
Phylum ciliophora
- include paramecium
- multinucleate
- macronucleus (metabolic functions)
- micronucleus (sexual reproduction)
- LOTS of cilia
- some have trichocysts/toxicusts which are organelles embedded in tissue, some have poison , prevents things from eating them and paralyze prey
(IN PARAMECIUM) conjugation
- sexual
- requires two organisms
- line up next to each other and fuse membrane between them so easily exchange
- one micronucleus (diploid) undergoes meiosis to form 4 haploid micronuclei
- three disappear and then one micronucleus remains and then goes through mitosis to form one copy of itself
- once you have the two copies, one remains but then they also switch one nucleus with the other paramecium that they are fused with
- then macronucleus disintegrates and micronuclei fuse to form diploid nucleus and that becomes new micro AND macronucleus
- INFORMATION EXCHANGED, DO NOT GAIN NEW/MORE INDIVIDUALS
(IN PARAMECIUM) binary fission
- asexual
- also called mitotic fission
- copies DNA by mitosis
- copies cytoplasm
- then splits
each makes duplicate of itself through mitosis, NO CHANGE IN GENETIC COMBINATION
Phylum Dinoflagella
- typically with 2 flagella, football spiral because of placement of flagella (the flagella almost form right angle)
- spinning in two diff directions, not most efficient but works
some dinoflagellates…
- cause “red tide”, which is blooms of red pigmented dinoflagellates
- toxins kill fish, make shellfish unedible
- if toxins are airborne can also cause human sickness
special genus of dinoflagellata…
- noctiluca
- very small, 0.2-2 mm (typically 0.5 mm)
- it is BIOLUMINESCENT
- produces chemical that produces own light
- they are photosynthetic
Zooxanthellae (dinoflagellata)
- has mutualistic relationship (endosymbiont) with sea anemone and corals)
- live inside other organism
- photosynthetic, creation own food and offer food and nutrients to host
- allows corals and anemone to get nutrients and zoo gets place to live = mutualistic
Phylum Apicomplexa
- endoparasites
first example of an apicomplexa is
- toxoplasma gondii
- parasite of cats, cattle, sheep, rodents, etc.
- 25% of world’s population infected
- main problem: pregnant woman infected via oocysts in cat feces or undercooked meat, crosses placenta and chance of birth defects to as bad as a miscarriage
- only reproduce sexually in cats,
- parasites in rodent inhibits parts of brain that processes fear, wants to be found by cat, messes with neural system
another example of apicomplexa is plasmodia
- causes malaria
- at least 4 species infect people
- ANOPHELES (genes of mosquito) (main mosquito vector)
- eradicated in US
- lot of cases by equator, warm and moist and undeveloped countries
- Mortality = 1 million/year
How a mosquito infects human
- mosquito saliva contains sporozoites (haploid), when mosquito bites you and pumps saliva into your body and they travel to your liver (6-15 days in liver)
- next stage of life are merozoites, these go to RBC (one single sporozoite can perform schizogony and become 8 different merozoite cells), each of these can inject own RBC
- next the merozoite become ameboid (develop pseudopods and move around in RBC) this is the tophozoite stage which they eat the hemoglobin and breaks down RBC and releases waste called hemozoin
- when hemozoin and merzoites released frmo RBC after it breaks down, causes fever (which is on 48 hour cycle), every 48 hours you get severe fever
- then repeat steps 2 and 3 and this is ASEXUAL CYCLE, genetic copies
can also develop severe….because…
anemia, all red blood cells getting destroyed and you can’t replenish them
sometimes merozoites in RBC can become….
- micro (sperm) and macrogametocytes (egg)
- (timing and formation not understood, don’t know why), occasionally when environment is right
- instead of asexual start to perform sexual reproduction
the cycle of this sexual reproduction is…
- mosquito may pick up the micro and macrogametocytes from biting another human
- when they enter the gut of mosquito, then fertilization occurs in mosquito
- diploid zygote, then meiosis occurs and results is sporogony
- releases the sporozoites and then these are transferred to human
signet ring stage is the…
trophozoite stage
phylum amoebozoa
- gel like ecto, fluid like endo, false feet (pseudopods = lobopodium)
phylum foraminifera
outer shell (test), many chambered, made of calcium
- white cliffs of dover England are made up of these
Phylum radiolaria
silica shell, pseudopod axopodia, false feet extend from little holes
Phylum Stramenopiles
axopodia supported by microtubule spines, covered in gel like substance
