BY 124L - Cusic 1

Protists

• All eukaryotic

• Most univellular

• Most aerobic respriation

• free-living, parasitic, or symbiotic

• heterotrophic, autotrophic, or mixotrophic

• NEED MOIST ENVIRONMENTS

Types of Protist Locomotion

flagella, cilia, pseudopodia, none

flagella

single, long hair-like extension used to sqim

ex. Euglena

examples of flagella protists

Supergroup Excavata: diplomonads, parabasalids, euglenozoa-like kinetoplastids and euglenids)

oomycetes (SAR)

Dinoflagellates (SAR)

Pseudopodia

Cytoplasm-filled projections of the cell membrane

• Ex: Amoebas

Examples of pseudopodia

Radiolaria, Foraminiferans, Tubulinids

Cilia

Short, hair-like extensions covering the cell wall

ex.) paramecium

examples of cilia

Ciliates, paramecium

immobile/none

Diatoms, Apicomplexans

Feed strategies

photoautotrophic, heterotrophic, or mixotrophic

photoautotrophic

photosynthetic (plant-like)

ex.) red algae

heterotrophic

• Ingestive (animal-like)

• Absorptive (fungus-like)

ex.) oomycetes and radiolarians

mixotrophs

An organism that is capable of both photoautotrophy and heterotrophy.

ex.) some dinoflagellates or euglenozoa

green algae

a and b

red algae

a and d

brown algae

a and c

diatoms

a and c

dinoflagellates

a and c

euglenids

a and b

Supergroups

• Excavata

• SAR

• Archaeplastida

• Unikonta

Excavata clades

diplomonads, parabasalids, euglenozoans

excavata

• excavated groove on one side of the cell body

• multiple flagella

• modified mitochondria

diplomonads

• mitosomes

• ANAEROBIC PATHWAYS

• parasitic

• two equal-sized nuclei and multiple flagella

• Giardia intestinalis - feces water "beaver fever"

parabasalids

• hydrogenosomes (reduced mitochondria)

• Trichomonas vaginalis

eugleonozoa

• unique flagella; spirl or crystalline rod-like structure

• predatory heterotrophs, photosynthetic autotrophs, mixotrophs, and parasites

• kinetoplastids and eugelozoids

kinetoplastids

• predatory heterotrophs and parasites

• termine flagellates in termite guts help digest cellulose

• trypanosoma bruceii: sleeping sickness; can cause Chagas' disease, heart failure, and blood sucking insects

• single, large mitochondrion with kinetoplast (mass of DNA0

• feed on prokaryotes, protists, and plants

Euglenids

• 1-2 flagella

• can be mixtrophs; photosynthesis when light is available; can go heterotrophic

• CHLOROPHYLLS A AND B; no cell wall

• pellicle (shape) and stigma (light sensitive organelle)

types of reduced mitochondria

• Hydrogenosomes

• mitosomes

Hydrogenosomes

• anaerobic

• parabasalids

• reduced mitochondria; can make hydrogen without oxygen

• lack all plastid

Mitosomes

• reduced mitochondria

• lack functional ETC

• Cannot use oxygen to extract energy from carbs

• diplomonads

ª lack all plastids

• no ATP generation or oxcidative phosphorylation

Supergroup "SAR"

Stramenopiles, Alveolates, Rhizarians

Stramenopila

• stramen = straw

• pila = hair

• autotrophs and heterotrophs

• file hair-like projections found on flagella

• "hairy" flagellum paired with a "smooth" shorter one

Stramenopila Clades

• diatoms

• brown algae

• oomycetes

diatoms

• unicellular

• glass-like cell wall of hydrated-silica; shoebox

• oceans and lakes; diatomaceous earth deposits

• abundant; photosynthetic activity affects CO2 levels

• CHLOROPHYLL A AND C

brown algae

• multicellular

• cold-water currents

• kelps

• walls have algin; thicken foods

• CHLOROPHYLL A AND C

• cellulose in walls

oomycetes

• Some unicellular, some multicellular with cellular units called hyphae

• Cell wall comprised of cellulose

• Diploid dominant life cycle (produce large egg)

• Heterotrophic, very important in decomposing organic matter

• Saprolegnia

alveolata

• have alvoli (membrane-enclosed sacs) under membrane

• wide variety of habitats

alveolata caldes

dinoflagellates, apicomplexans, ciliates

dinoflagellates

• cells wit cellulose and TWO FLAGELLA in grooves

• marine and freswater

• CHLOROPHYLL A AND C

• causes red tides from red cartenoids

• symbiotic relationships with coral

• photoautotrophic, heterotrophic, or mixotrophic

• threadlike filaments

apicomplexans

• endoparasites - LIVES IN HOST

• unicellalur

• apical complex penetrates RBC

• complex life cycles: several hosts and both sexual and asexual components

• Plasmodium - malaria

• no organelle for movement

ciliates

• use cilia for locomotion

• predators of bacteria or smaller protists

• cellia can cover entire surface or be clustered

• binary fission reproduction

• toxin

• oral groove: place of ingestion

• food and contractile vacuoles

• anal pore for waste

Rhizaria

foraminiferans and radiolarians

radiolarians

- move via axopodia/pseudopodia; float and feed

• silica in internal skeleton

• marine waters

• unicellular and heterotrophic

foraminifera/forams

• bears pores

• shells (tests)

• unicellular

• heterotrophs with symbiotic, photosynthetic algea

• marine and freshwater; attach to rocks or algae

• limestone, flint

Archaeplastida

• origin of plastids

plastids

organelles responsible for photosynthesis

archaeplastida clades

• red algae

• green algae

red algae

multicellular

• most photoautotrophic

• can be hetertrophic or parasitic (lack chlorophyll)

• chloroplasts with CHLOROPHYLL A AND D

• no flagellated gametes

• some contain calcium carbonae walls

• nori wraps for sushi and agar

green algae

• unicellular and multicellular

• photosynthetic: chloroplasts with a and b

• freshwater

• carbs starch

• cell wall of cellulose

• complex life cycles: asexual and sexual stages

green algae 3 mechanisms for greater size and complexity

• formation of colonies of individual cells (volvox) and filamentous forms that make stringe masses (pond scum)

• production of true multicellular bodies via cell divisiona nd differentiation

• repeated karyokinesis (nuclear division) without cytokinesis)

Super unikonta

similar myosin protein structures

unikonta clades

amoebozoa

^plasmodial slime molds

^cellular slime molds

tubulinids

entamoeba

amoebozoa

• lobe or tube shaped pseudopodia for movement

• cytoplasm is in ectoplasm and endoplasm and flow in opposite directions

slime molds amoebozoa

plasmodial and cellular

plasmodial slime molds

• large, unicellular mass called plasmodium;

• diploid; plasmodium is feed stage

• heterotrophic on detritus (moist soil, rotten logs)

• convergent evolution to act like fungi

plasmodium slime mold life cycle

1. diploid zygote undergoes multiple mitotic divisions wihtout cytokineses; forming LARGE UNICELLULAR PLASMODIUM

2. plasmodium produces sporangia

3. sporangium contains diploid cells which undergo meiosis to produce haploid spores

4. haploid spores contain either a flagellate or ameoboid cell which fertilize with opposing to produce a new diploid zygote

Cellular slime molds

• exist as indiviudal haploid cells, but can form aggregate when food is scarce

• individual cells are feeding state

• aggregate functions as an asexual fruiting body

• heterotrophic on detritus (moist soil, rotten logs)

• convergent evolution to act like fungi

Cellular slime mold life cycle

1. solitary haploid amoebas divide periodically asexually mitosis

2. during a sexual cycle, tow haploid amoeabs that accumlate during food scarcity fuse to form a diploid zygote which goes through meiosis to produce haploid amoebas

3. solitary haploid amoebas form an aggregate during food scarcity

4. aggregate migrate sbefore stopping and forming a stalk with a fruiting body

5. amoebas within aggregate crawl up the stalk of the fruiting body and develop into spores

6. spores are released and produce solitary amoeabs in favorable conditions

tubulinids

• Unicellular

• Most are heterotrophic on bacteria, other protists, or detritus

• Large and diverse group of amoebozoans

• Amoeba

• Ubiquitous in soil, freshwater, and marine

Entamoeba

• Unicellular

• Parasitic

• Entamoeba spp.

• Infection possible in all vertebrates and some invertebrates

• E. histolytica is the causative agent of amoebic dysentery and spreads via contaminated drinking water

Flagella

Domain Bacteria

3 shapes: cocci, spirilla, bacilli

cyanobacteria

cyanobacteria

Photosynthetic w/o chloroplast: Photosystems I and II as well as

Chlorophyll A within thylakoid membranes

• Heterocysts present in nitrogen-fixing species

• Anabaena and Oscillatoria