chapter 22- algae Flashcards
what are the two types of edible algae
- Spirulina (arthropspira)
- cyanobacteria
- 60 % protein
- most nutrient dense on Earth - Dulce (Palmaria palmata)
- red algae
- source of dietary fiber in Iceland
basic characteristics of algae
- primarily nonvascular photosynthetic organism
- range from unicellular to 60-meter-long giant kelp
- not a monophyletic group (can include prokaryotes and eukaryotes)
basic body structure of algae
thallus
what type of chlorophyll is present in all types of algae?
chlorophyll a
- uses excited electrons and donates electrons across complexes to drive energy production
what type of photosynthetic pigments are present in green algae and euglenoids?
chlorophyll a, b, and carotenoids
cyanobacteria
- blue green algae
- some are able to fix nitrogen from air, serves importance in nitrogen cycle
- prokaryotes
- storage: glycogen
- cell wall: peptidoglycan
- habitat: marine, freshwater, terrestrial
dinoflagellates
- unicellular
- autotrophs, mixotrophs, or heteroptrophs
- storage: starch
- cell wall: cellulose plates
- habitat: marine, freshwater
- many contain animal toxins
- can lead to “red tides”
- photosynthetic pigments: chl a, c and carotenoids
what are structural components of dinoflagellates
- have hard cellulase plates on the exterior
- 2 flagella help propel through water
diatoms
- unicellular
- storage: oil
- habitat: marine, freshwater
- cell wall: silica cell walls
- aggregations produce “ diatomaceous Earth”
- used in pool filters and serve as an insecticide for plants and homes
- like little glass pieces so bugs don’t want to eat them
- polishing uses
- photosynthetic pigments: chl a, c and carotenoids
euglenoids
- unicellular
- storage: paramylon
- cell wall: pellicle; protein containing flexible covering
- have 1-2 flagella for locomotion
- mixotrophs
- senses light with eye spot, can have uses to move near light to perform photosynthesis
- photosynthetic pigments: chl a and b, and carotenoids
green algae
- habitat: freshwater and marine (most diverse in freshwater)
- unicellular, colonial, filamentous, or multicellular
- photosynthetic pigments: chl a and b, carotenoids (same as land plants)
- storage: starch
- cell wall: cellulose
chlorella
- type of green algae
- unicellular
- function as biofuel
- have chloroplast
- translucent cell
- non-motile
red algae
- unicellular, branched sheets
- storage: Floridian starch
- cell wall: cellulose
- habitat: mainly marine
- some have walls containing high amounts of agars and carageenans
- commerically used as food thickeners, in gel electrophoresis
- coralline algae: have rigid aggredations of calcium in walls
- commonly found in coral reefs, aggregate together.
brown algae
- habitat: mostly marine
- branched filaments, sheets
- storage: laminarin
- cell wall: cellulose
-ex. kelp: “trees of the coastal marine environment”. found on rocky coastlines, attach to rocks. - float: holds air to allow it to float for more access to sunlight
- holdfast: attaches to rock coastlines
why have a variety of photosynthetic pigments evolved in marine algae but not in land plants?
marine algae are able to adapt to different depths or water. accessory pigments vary depending on the light they can capture at those depths.
- blue wavelengths can reach deeper levels
spirulina
high protein food additive
- cultivated by the Aztecs
health omega3-fish oils
-originally produced by algae and are consumed by fish
porphyra (red algae)
wrapper for Japanese sushi
what advantages do algae serve as a biofuel?
- easy to grow
- high concentration of lipids can be extracted and purified to make diesel
- grows fast
- grow in large numbers
- more affordable
algal toxicity
- toxic cyanobacteria
- red tides from dinoflagellates releases toxins that can accumulate in shellfish
- pfiesteria (dinoflagellate): can secrete toxin to kill then feed off fish, leading to dermatitis in humans
caulerpa taxifolia
invasive species of algae
characteristics of invasive species of algae
- can outcompete native species for resources
- don’t have predators
- reproduce in high numbers
