Lecture 19 Flashcards
What is special about the Protista kingdom?
- an unnatural grouping, should be several kingdoms and only out of convenience aren’t
- some are protists more distantly related from one another than humans from fungi
What defines the kingdom Protista?
Unnatural grouping
• Diverse and simple eukaryotic cell
types
Comprised of
: • Producers - several divisions of
photosynthetic algae
• Consumers - ciliates, colourless flagellates, parasites, pathagens
• Absorbers & Recyclers - slime moulds, water moulds
producers= have chloroplasts, photosynthetics like plants sort of
consumers= eat things like animals
absorbers recycles= like fungi on land sort of
What is the importance of the age of slime?
when protists evolved= lasted that age for 3 billion years
-A long empire – lasting over 3 billion years. Microscopic assemblages of single-celled organisms (e.g., Bacteria (Cyanobacteria), Archaea and Protists) Microbial mats held
together by organic ‘glues’, creating the perfect habitat.
The evolution of hungry, primitive animals (metazoans) ended their dynasty about 500 million years ago. Few fossils, but mats survive today in harsh environments.
can still find the slime layers.
-changed because larger animals developed and ate it
Why are the primary producers so colourful?
They posses diverse chloroplasts and pigments.
What are macroalgae (seaweeds) important for?
-important primary producers
What are the three divisions of seaweed?
Rhodophyta (red algae)
• Chlorophyta (green algae)
• Phaeophyta (brown algae)
• Each group has a different combination of pigments and a range of other features that distinguish them.
Where did the green, red and brown algae get their chloroplasts?
red and green= primary endosymbiosis
brown- secondary (protistan pirate)
Why can there be 4 membranes in protistan pirates?
first two from cyanobacteria, thrid= cell membrane of the eukaryote with the chloroplast, 4th= sometimes, so food vacuoles so 3 or 4 membranes
Why is red algae important?
Commercially harvested for agars and carrageenans for science and the food industry.
-gels for molecular biology and biochemistry
-thickening and stabilising agents for the food industry
-big and up and coming industry
-agarose!-the key= not in all red algae
-30% of red algae= in Australia, 70% only found here
toothpaste= has red algae product
-cosmetics too
What does the colour of red algae depend on?
- depends on the concentration of Chlorophyll A, plus phycoerythrin and phycocyanin
- red algae can look brown or green, can get range of colour so it depends on accessory pigments as well
What were the ancestors of land plants?
green algae
What chlorophyl do green algae have?
Chloroplastsaregreen- (chlorophylls A , B) and are primary endosymbionts.
What are green algae used for commercially?
- major biofoulers &
polluters. - solar energy, biofuels - grow really quickly
What are brown algae?
• Marine seaweeds
• Protistan pirates -
chloroplast from a red alga and contains Chl A + C and the brown pigment fucoxanthin.
• Cell walls contain a major source of commercially important alginates used in the food industry (e.g. kelp farming)
How do seaweed have sex?
tied into the lunar cycle- moon comes up= release sperm, eggs= sperm goes up to light
then eggs drop down