AqBot: Anatomy Pt 1

Cyanobacteria cell structures

• absent/present membranes, organelles

• storage

• important structures

• pigments

• No nucleus or membrane-bound organelles. Contains cell membrane. Cell wall is the outer peptidoglycan layer

• Phosphate bodies store phosphate, polyglucan granules store carbs, and cyanophycin store nitrogen

• Gas vacuoles/vesicles = creates surface blooms of cyanobacteria like Anabaena, has hydrophobic inner surface and hydrophilic outer surface

• Carboxysomes = free-floating enzymes to fix CO2, Rubisco

• Thylakoids = chlorophyll a (maybe b, d, f)

• accessory pigments = phycobiliproteins like C-phycocyanin, allophycocyanin, and C-phycoerythrin

• Rhodophyta cell structures

• unique characteristics

• chloroplast envelope has 2 membranes, nucleus, mitochondria, and golgi bodies

• Pyrenoid = carbon fixation

Rhodophyta

• # of membranes surrounding plastid

• accessory pigments

• arrangement of thylakoids

• storage

• endosymbiosis type

• endosymbiont

• endosymbiont remnant

• 2

• Chl a & c, phycobillisomes

• 1, unstacked, even

• Floridean starch

• primary

• cyanobacterium

• none

Chlorophyta

• what are its closely related relatives?

• cell structures

• unique characterisitcs

• land plants branched off from green algae

• this is a colonial cell. Contains nucleus, chloroplast has 2 membranes, pyrenoid, flagella, golgi bodies, mitochondria, cell wall

• starch is INSIDE the chloroplast (like in plants), eyespot at base of flagella, colony

• Describe the structural component of Chlorophyta cell walls

• Describe the scales of Chlorophyta cell walls

• Chlorophyta cell walls are mostly made up of cellulose. Some are made of xylan or mannan including caulerpales, glycoproteins, and volvocales

• Scales include acidic polysaccharides (prasinophyceae) and theca (glycoproteins and polysaccharides) and motile cells of chlorophyceae

Describe the pigments of Chlorophyte chloroplasts

• mainly chlorophyll a and b

• carotenoids, mainly lutein, can accumulate under stress like low N, high light, high salinity

  • occurs when orange-red passes up the food chain (i.e., seen in flamingos eating shrimp) bc animals cannot synthesize pigments

• pigments accumulate b/w thylakoids which are 2-6 bands stacked

Describe the contractile vacuoles of Chlorophyta: formation, use

• 2 are present at the base of the flagella

• alternately contract to control water content of the cell

Chlorophyta

• # of membranes surrounding plastid

• accessory pigments

• arrangement of thylakoids

• storage

• endosymbiosis type

• endosymbiont

• endosymbiont remnant

• 2

• chlorophyll a & b, carotenoids (lutein)

• 2-6 bands, stacked

• starch is inside the chloroplast (similar to land plants)

• primary

• cyanobacterium

• none

Euglenophyta

• # of membranes surrounding plastid

• accessory pigments

• arrangement of thylakoids

• storage

• endosymbiosis type

• endosymbiont

• endosymbiont remnant

• additional features

• 3 membranes around plastic/chloroplast

• chlorophyll a & b, carotenoids

• thylakoid has 3 bands, stacked

• paramylon is storage product

• secondary endosymbiosis type

• engulfed chlorophyte

• no remnant

• 1-2 flagella emerge from canal containing fribillary hairs, contains mucocysts to produce mucus, does NOT have a cell wall but contains a pellicle resembling a rigid tooth structure, has mesokaryotic nucleus

In Euglenophyta, describe the paramylon storage

• stores polysaccharides, makes up ~70% of weight, insoluable crystal

In Euglenophyta, describe the pellicle

• protein-based outer covering in the form of spiral (like a barber pole) or straight strips

• flexible => able to change shape, promoted inch worm movement

• there’s a thick and thin side, muciferous bodies allow lubrication during movement, microtubules are associated

In Euglenophyta, describe the muciferous bodies: secretions and physical position

• produces polysaccharides and glycoproteins

• Occurs in helical rows under pellicle, open to the outside through pores, can accumulate at posterior end to attach to substrate

• has thick slime coating, releases water soluable mucus when irritated

In Euglenophyta, describe the mesokaryotic nucleus

• shares characteristics of eukaryotes and prokaryotes

• chromosomes are permanently condensed and are in high numbers, nucleolus does not disperse during cell division

Dinophyta

• # of membranes surrounding plastid

• accessory pigments

• arrangement of thylakoids

• storage

• endosymbiosis type

• endosymbiont

• endosymbiont remnant

• additional features

• cell morphology (from top down)

• aka dinoflagellates

• most have 3 membranes, but can have 4-5 if tertiary endosymbiont type, around plastid/chloroplast. Additionally, pH is acidic b/w chloroplast envelope and ER which helps enhace CO2 retention using Rubisco as this trait evolved when CO2 was low globally

• chl a & c; accessory pigments vary b/w peridinin and fucoxanthin

• thylakoid has 3 stacked bands

• starch (similar to Floridean)

• secondary and tertiary endosymbiosis

• engulfed rhodophyte

• none

• normally has 2 flagella, mainly found in tropical environments, condensed nucleus w/ over 100x more DNA than protists, may have scales, may have simple or complex eyespots, may have projectiles

• top = epicone/epitheca, middle = cingulum/girdle (contains transverse flagella), bottom = hypcone/hypotheca, sulcus allows longitudinal flagella to extend out of.

• In Dinophyta, describe the Amphiesma structure

• Where are the scales formed

• Bc dinoflagellates may or may not be covered in thecal plates, this group has an Amphiesma structure so thecates have scales/ are armored dinoflagellates while athecates do not have scales/ are naked dinoflagellates. Tabulation is the number and arragement of plates and sutures

• scales are formed in the Golgi and release to outside the cell which will then fuse to become part of the cell wall

In Dinophyta, list and define the 3 types of projectiles

• Trichocysts = used for slowing down and stopping prey items

• Mucocysts = used to shoot mucus for eating and defense (similar to euglenids)

• Nematocysts = stinging cells

In Dinophyta, why are thecal plates important for identification?

• thecal plates are the cellulose plants under the plasma membranes which contain striations along its boundaries used for identification

In Dinophyta, describe thecal plates and its cell division

• Thecal plates may be shared and new plates can be added by daughter cells

• Thecal plates are constantly being shed and replaced

• In Peridinoids, theca shed and an ecdysal cyst protects the cell until the new theca is formed which will replace the cyst

Cryptophyta

• # of membranes surrounding plastid

• accessory pigments

• arrangement of thylakoids

• storage

• endosymbiosis type

• endosymbiont

• endosymbiont remnant

• additional features