Midterm 2-Feeding and trophy Flashcards by Jessica Kasapi

Trophic strategies

What 6 things does all cellular life need to take from the environment?

Water 2. Energy 3. Sources of Carbon 4. Reducing power (e donor) 5. Electron acceptor 6. Sources of other elements (n/p/s/fe)

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Trophic strategies

Define 2 Sources of energy

Chemotrophs: use chemical bonds in molecules Phototrophs: use light/photons

ex. animals/plants

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Trophic strategies

Define 2 sources of reducing power?

Electron donor/oxidations

Organotrophs: use organic molecules Lithotrophs: use inorganic molecules

ex. Glucose&lipids/ water in photosynthesis

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Trophic strategies

Define 2 sources of electron acceptors

Not referred to as food

Aerobes: use oxygen Anerobes: use anything else

ex. humans/ Co2 in photosynthesis

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Trophic strategies

Define 2 sources of Carbon

Heterotrophs: use organic molecules Autotrophs: Use inorganic molecules

ex. Sugars/photosynthesis uses CO2 (inorganic C)

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Trophic strategies

Define sources of other elements

*Nitrogen/Phosphorus/Sulfur/Iron

Variable- can get N from proteins in organic molecules (us) or from inorganic in soil (ammonia/nitrate in plants)

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Trophic strategies

Define photosynthesis

oxygenic

The process of fixing Co2 into organic compounds (autotrophy) by using energy obtained from photons (phototrophy)

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Trophic strategies

What is anyoxygenic photosynthesis?

An unrelated process developed by some bacteria that does not produce oxygen

E- donor is not water

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Trophic strategies

What 2 classes do all eukaryotes fall into?

Chemoorganoheterotrophs or photolithoautotrophs

heterotrophs (organic)/phototrophs (inorganic)

Can be aerobic or anaerobic

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Feeding in Protists- Heterotrophs

What groups can do osmotrophy?

Bacteria/Archae are great at this, the only eukaryote is FUNGI

fungi use Hyphae for surface area

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Feeding in Protists- Heterotrophs

What is osmotrophy?

Digestive enzymes are excreted outside cell –> broken down into smaller molecules that are then actively transported in

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Feeding in Protists- Heterotrophs

Name 2 reasons why Eukaryotes are not great at osmotrophy

Less metabolically diverse: fewer and less effective digestive enzymes 2. ** Surface to volume ratio**: Eukaryotes tend to be bigger than bacteria

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Feeding in Protists- Heterotrophs

What are Oomycetes

Stramenopiles

POTATO BLIGHT

Efficient parasites, have hyphae- Unrelated (but not totally independant) from Fungi

convergent evolution- genes from horizontal gene transfer from FUNGI

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Feeding in Protists- Heterotrophs

What is phagotrophy?

First cells to eat another- evolution game changer

The entire particle is engulfed by membrane through vacuoles

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Feeding in Protists- Heterotrophs

What are the 3 types of phagotrophy?

Define

Raptorial: Search and move towards prey 2. Diffusion: prey bumps/falls into it 3. Filter: filters prey from surrounding water (may generate current)

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Feeding in Protists- Heterotrophs

How do protist predators find prey?

Raptorial feeding

NOT SIGHT, maybe hearing YES smell /CHEMICALS

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Feeding in Protists- Heterotrophs

Define Extrusomes

Raptorial feeding

Organelles that are just below the plasma membrane, function to do exocytosis and release content

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Feeding in Protists- Heterotrophs

What does Acantharian feeding use?

Radiolarian

Diffusion feeding- Prey touches axopods which triggers kinetocysts to release content (sticky glue) then retracts to centre of cell where it will feed

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Feeding in Protists- Heterotrophs

How do ciliates feed?

2 ways

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Raptorial feeding- Have toxicysts to inject poison to stop from swimming, then injests it ALSO filter feeding

Apex predators of protists

Feeding in Protists- Heterotrophs

How do lobose ameobas feed?

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Raptorial: overwhelm with size and trap

Feeding in Protists- Heterotrophs

How do Choanoflagellates feed?

Opisthokonta

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Filter feeding: Use flagella to generate water current and filter to find prey of right size, feeds at “collar”

Use “Stock” or “Colonies” to anchor to something

Feeding in Protists- Heterotrophs

How do Excavata feed?

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Filter: Have a feeding grove surrounded by flagella that beat to generate water current

Feeding in Protists- Heterotrophs

What is the main difference between filter and raptorial feeding?

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Filter feeding can only be eat things SMALLER than them

Feeding in Protists- Heterotrophs

What is a cytosome?

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A specialized part of the cell that does phagocytosis with no rigid structures below the surface

Ameobas are an exception

# Feeding in Protists- Heterotrophs How do dinoflagalletes feed: palium feeding? | (half photosynthetic half heterotrophic) ## Footnote Alveolata

Palium feeding: A large veil extension of the cytoplasm that envelops and digests LARGE prey outside of the cell then transports nutrients in | Extensions are classified as psudopodia

# Feeding in Protists- Heterotrophs How do dinoflagalletes feed: Myzocytosis | Half photosynthetic half heterotrophic ## Footnote Alveolata

Pierce plasma membrane of prey and "suck in" nutrients

# Feeding in Protists- Heterotrophs How does Vampyrellids feed? | Rhizaria- weird example

Fillose ameoba that pierce holes through thick cellulose algae walls and ingest the whole cell | Myzocytosis

# Feeding in Protists- Heterotrophs How does pseudomicrothorax feed? | CIliate- weird example

Eats cyanobacteria (forms long filamentous colonies) cytosome is reinforced by Mts for specialized feeding of long prey

# Feeding in Protists- Heterotrophs Steps of digestion | 5

1. Food vacuole detaches from cytosome to become Digesive vacuole (DV) 2. **Acidosomes** fuse with Dv and lower pH 3. **Lysosomes** fuse with DV and release lytic enzymes 4. Digested contents + enzymes pinch off in vesicles 5. Undigested content/waste is defecated when DV fuses with *Cytoproct*

# Feeding in Protists- Heterotrophs What is Cyclosis

The digestive vacuole moves slowly in a pre-defined path within cytoplasm

# Feeding in Protists- Heterotrophs Prey fighting back: shapeshifting | Euplotes- Ciliate

Senses predators and flattens to become harder to eat | Euplotes- Ciliate

# Feeding in Protists- Heterotrophs Prey fighting back: defensive extrusomes | Paramecium

Uses trichocysts to stun predators

# Feeding in Protists- Heterotrophs Prey fighting back: Defensive symbionts | Euplotidium- ciliate

band of spherical balls (symbiotic bacteria) OUTSIDE cell that stun prey | Not extrusomes- outside cell

# Feeding in Protists- Heterotrophs Parasites: intra vs extra cellular | Apicomplexans

Intra: surrounded by food, can do osmotrophy (toxoplasma/plasmodium) Extra: mostly phagotrophic (gregarians)

# Feeding in Protists- Heterotrophs How do Microsporidians feed? | Opisthokonts

Energy parasites- steal ATP from host | Microsporidian - Opisthokonts

# Feeding in Protists- Mixotrophs What is a Mixotroph?

An organism that can do both heterotroph and autotroph strategies

# Feeding in Protists- Mixotrophs 3 Mixotroph strategies

1. Algae- photosynthetic dinoflagalletes or unicellular green algae 2. Heterotrophs with algal symbionts 3. Kleptoplastidy

# Feeding in Protists- Mixotrophs What is a Haptonema? | Haptophytes

A specialized feeding structure in Haptophytes that moves food to opposite side of cell

# Feeding in Protists- Mixotrophs Micromonas feeding strategy | Green algae

**Mixotroph**- does photosynthesis and eats bacteria (phagocytosis)

# Feeding in Protists- Mixotrophs Why does an Algal symbiont not count as an organelle?

The Algae are not dependant on the host, can still live on its own | NO PROTEIN TARGETING

# Feeding in Protists- Mixotrophs Why are kleptoplastids often lost quickly?

The host is missing essential genetic information to keep plastid alive

# Feeding in Protists- Mixotrophs List groups that do Kleptoplastidy?

Foraminiferan, Euglenid, Dinoflagallete and SOME animals!

# Feeding in Protists- Mixotrophs Who does Mesodinium steal plastids from? | Heterotrophic ciliate

Cryptophyte (secondary red algae, 4 membranes)

# Feeding in Protists- Mixotrophs Why is Mesodinium rubrum so good at keeping plastids alive?

Not only steals the plastid, also steals the nucleus from DIFFERENT cryptophytes

# Feeding in Protists- Mixotrophs How does Dinophysis get its plastid (cryptophyte) | Dinoflagallete- heterotrophic

By eating mesodinium and keeping ONLY plastid- no nucleus

# Feeding in Protists- Mixotrophs How can Dinophysis keep its plastid alive if it does not steal nucleus as well? | Dinoflagallete- heterotrophic

Ancestor of dinophysis used to have plastid- still has plastid derived genes (red algae 3 mem) | Digests everything but 3 membraned plastid- same as ancestors

Midterm 2-Feeding and trophy Flashcards

(46 cards)