Feb. 13th (Exam 2) Flashcards
What is “Spirulina”?
What percent of this algae is protein?
Most nutrient dense plant on earth?
This is the nutrient dense supplement that people take from the algae Arthrospira.
60%
Not a plant, but is very nutrient dense.
What is Dulse?
This is a red algae that is edible and is a good source of dietary fiber in iceland.
It looks like red seaweed.
What are cyanobacteria?
Eukaryotes or Prokaryotes?
They are a group of photosynthetic bacteria that are often called “blue-green algae” although they are not
technically algae.
Prokaryote
What are some cyanobacteria very important to the ecosystem?
They are able to fix Nitrogen from the air which is important in the nitrogen cycle.
How have algae been characterized historically?
Historically, they have been grouped by their photosynthetic pigments.
What is special about chlorophyll a?
it is the only pigment molecule that can donate electrons to the electron transport chain in oxygenated photosynthesis.
Green algae and euglenoids have chlorophyll a, b and carotenoids, making them similar to?
Why?
Land plants photosynthetic pigmentation.
The similarity in pigments especially chlorophyll b, makes them similar.
What is much of the phylogenetic separation of algae based on?
Ribosomal RNA
What are algae?
Vascular?
What are the ranges of size?
They are a primarily aquatic,
non vascular photosynthetic organism.
They can be unicellular and be as big as 60 meter long kelp.
What is the basic body structure of algae?
What does this mean?
Basic body structure is thallus.
This essentially means their body is undifferentiated.
They don’t have distinct tissues, and have a simple uniform body.
Are algae a monophyletic group or rather an informal name?
Do they have both eukaryotes and prokaryotes?
Informal name
Both
Describe dinoflagellates by:
Cell type
Cellulose composition
Locomotion mechanism
Energy maintenance
- They are unicellular
- They have hard cellulose plates
- Have two flagella that help them spin through the water
- They can be autotrophs, heterotrophs or mixotrophs
What do some dinoflagellates release?
Animal toxins
What are red tides?
What can contribute to them?
This is when there is a rapid growth or bloom of certain marine species that can cause the ocean to turn a certain color (sometimes red)
Dinoflagellates can contribute to them.
Describe diatoms by:
Cell type
Cell walls
- Unicellular
- Ornamented silica cell walls
What do aggregates of diatoms produce?
They produce diatomaceous earth which is kind of like sand.
What is significant about the cell division that occurs in diatoms?
For each successive division one of the offspring will be smaller and one will be the same size as the parent, because it creates new halves from the parent
Describe euglenoids by:
Locomotion mechanism
Covering instead of cell wall
Energy maintenance
Unique sense
1.They have 1/2 flagella for locomotion
- Flexible protein covering instead of a rigid cell wall
- They are mixotrophs
- They have an eye-spot that sense light
Describe green algae by:
Marine or Freshwater?
Forms
Photosynthetic pigments
- Both marine and freshwater, but more diverse in freshwater
- a. Unicellular
b. Colonial
c. Filamentous
d. Multicellular - Same pigments as land plants
Is Chlorella a type of green algae?
What cell type do Chlorella exist as?
What do they look like?
Yes
Unicellular.
Tiny green balls
Where is red algae usually found?
Marine environments
What are agars and carrageenans?
Where do we get them?
They are used as commercial food thickeners
They are found in the cell walls of some red algae.
What are coralline algae an example of?
What is special about their cell walls?
Red algae
They have rigid aggregations of calcium in their cell walls.
What is Kelp: “the trees of the coastal marine environment” an example of?
Brown algae
What are the four structures that we saw in the thallus body structure of brown algae?
- Blades - “leaves”
- Float - base of “leaves”
- Stipe - cord that attaches “leaves” to base
- Holdfast - connector structure
Why have a variety of photosynthetic pigments evolved in marine algae but not land plants?
Marine algae evolved a variety of photosynthetic pigments to efficiently capture a broader range of light wavelengths, especially in the underwater environment where light is scattered and absorbed differently than in the air.
Red - long wavelength absorbed easily
Blue - short wavelength not absorbed easily
What is the importance of algae in the diet?
- High protein content can be used as additive
- Health omega-3 “fish oils” can be obtained by eating algae that make it.
- Type of red algae “Porphyra” is used to wrap sushi in Japan
What do we think that the israelite “manna” was?
Nostoc
What are the potential advantages of using algae as a biofuel?
- It doesn’t take up land mass like other biofuels do (corn)
- We don’t typically eat algae, so it avoids the “Food Vs. Fuel” issue
- Doesn’t require a lot of space to grow
- Grows really fast
Where do we get the stuff to make DNA gels?
Red algae
- Carrageenan (thickening agent)
- Agar (makes agarose)
What is diatomaceous earth used for?
Polishing and filtering stuff
Why are red tides from dinoflagellates concerning?
Because they can release toxins that accumulate in shellfish
Specifically, what does the species of dinoflagellate “Pfiesteria” do to humans?
It secretes a toxin that is used to kill and then feed off fish, and then it causes dermatitis in humans
What is Caulerpa taxifolia commonly known as?
What type of algae is it?
What are the characteristics of this algae that make it concerning?
Invasive algae
It is a type of green algae
- Grows fast
- No natural predators
- Not native to area (good at adapting)
- Disrupts ecosystems
