Algae (photosynthetic protist)

Algae

Plantlike protists

Prasinophyte

smallest free living eukaryote of the genus Ostreococcus

auto-

means self,own

algae morphology

unicellular

colonial

filamentous

larger forms such as seaweed

club like

polyphyletic group

A taxonomic grouping consisting of several species that lack a common ancestor (more work is needed to uncover species that tie them together into a monophyletic clade).

algae locomotion

flagella or gliding

algae cell walls are made of

cellulose

pellicle

thick cell walls of algae

phycocolloids

chemicals in cell walls that help improve flexibility and strength and may be extracted for human use through hot water

3 major phycocolloids

(1) Alginates

(2) Agars

(3) Carrageenans.

Carageenan

A substance in the cell wall of red algae that is used commercially as a smoothing agent

Alginates

consist of calcium salt of alganic acid that is extracted from brown seaweed. highly permeable and non-occlusive. requires a secondary dressing. based on the interaction of calcium ions in the dressing and the sodium ions in the wound exudate.

Agar

a gel-like polysaccharide compound used for culturing microbes; extracted from certain red algae

Phycology

study of algae

Jean Pierre Etienne Vaucher

First to propose the classification of algae

Jean Pierre Etienne Vaucher 3 groups classification of algae

Conferves, Ulves, Tremelles

Johann Friedrich Link (1820)

classified algae on the basis of the pigment color and structure

Felix Eugene Fritsch

-algae should not be divided into phyta, instead only classes

-Algae were classified into eleven classes based on structure and reproduction of the algae (based on pigmentation, reserve food and flagellation, thallus structure, modes of reproduction and life cycles)

-Father of Phycology

Father of modern phycology

William Henry Harvey

William Henry Harvey

divided the algae into four major divisions (phylum) on the basis of their pigmentation

Plankton

Tiny algae and animals that float in water and are carried by waves and currents.

Responsible for most of Earth's oxygen

Algae

Algal Groups

Chlorophytes (green algae)

Rhodophyta (red algae)

Chrysophyta (golden brown algae and diatoms)

Phaeophyta (brown algae)

Pyrrophyta (dinoflagellates)

Euglenophyta (Euglenids)

International Code of Botanical Nomenclature

Book that standardizes rules governing the naming and classification of plants

International Code of Botanical Nomenclature suffixes

phyta for division

phyceae for class

ales for order

inales for suborder

aceae for family

oidease for subfamily

Greek based name for genus, latin for species

Green algae

-Photosynthetic protists that include unicellular, colonial, and multicellular species with grass green chloroplasts; closely related to true plants.

-Present in marine habitats but not as important as red and brown

-same chemistry and morphology as plants

-Phylum Chlorophyta

-7000 species

-land plants may have evolved directly from green algae

-distributed mainly in estuaries and tidal pools

Green Algae (Chlorophyta) examples

Chalmydomonas (1 cell)

Pandorina (clump)

ulva (sphere)

Ulothrix (filament)

Ulva (sheet)

dead man's finger

Spirogyra

Filamentous green algae

water silk

mermaid's tresses

blanket weed

Colonial green algae

Volvox

Red algae

-Phylum Rodophyta

-phycobilins causes red appearance

-largest group of seeweds, about 4000 seaweeds most exclusive in marine

thallus

The body of a plant-like organism that is not divided into leaves, roots, or stems.

coralline red algae

secretes CaCO3 to withstand waves

involed in formation of coral reefs

Carrageenan as a product

-used for stabilizing chocolate milk, eggnog, ice cream, sherbets, instant puddings, frostings, creamed soups.

-similar to agar but needs higher concentration to form gel

-made from Gigartina stellata, Chondrus crispus and Euchema

Agar

a gel-like polysaccharide compound used for culturing microbes; extracted from certain red algae

made from Gelidium, Gracilaria, Pterocladia, Ahnfeltia

Brown Algae

Phylum Heterokontophyta, class phacophyta

most complex thalli

Fucoxanthin dominates over chlorophyll

primary producers on temperate and polar rocky coasts

almost 1500 species are marines

Phaeophyta (brown algae) examples

Kelps - underwater forest, can grow 50 cm per day

Brown algae product

alginate/alginic acid

Phylum Chrysophyta (golden algae)

3 types :

Yellow green algae

golden brown algae

diatoms

Diatoms (Stramenopiles)

photosynthetic stramenopiles that excrete protective cilia shells and reproduce using both asexual and sexual reproduction; only the males in this species have flagella, and they are common in oceans