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 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
dinoflagellates
- unicellular
- autotrophs, mixotrophs, or heteroptrophs
- many contain animal toxins
- can lead to “red tides”
what are structural components of dinoflagellates
- have hard cellulase plates on the exterior
- 2 flagella help propel through water
diatoms
- have ornamented silica cell walls
- aggregations produce “ diatomaceous Earth”
- used in pool filters serves as an insecticide
- polishing uses
euglenoids
- have 1-2 flagella for locomotion
- protein containing flexible covering instead of a rigid cell wall
- mixotrophs
- senses light with eye spot, can have uses to move near light to perform photosynthesis
green algae
- freshwater and marine (most diverse in freshwater)
- unicellular, colonial, filamentous, or multicellular
- have photosynthetic pigments, same as land plants
chlorella
- unicellular
- function as biofuel
- have chloroplast
- transluscent cell
- non-motile
red algae
- 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
- mostly marine
-ex. kelp: “trees of the coastal marine environment”. found on rocky coastlines, attach to rocks.
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 oilds
-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
