Transcript bio120 lab--proks and protists-

Classification of Living Things
(based on lab manual….this is not the way things are currently grouped*):
this week we look at the groups in red
• Domain Prokarya— made of prokaryotic cells
– “Kingdom” Archaea
– “Kingdom” Bacteria
• Domain Eukarya— made of Eukaryotic cells
– “kingdom protista”
• protozoans— “animal” like protists
• algae— “plant like” protists
– Plant Kingdom
– Animal Kingdom
– Fungi Kingdom
–
* new groupings include domain bacteria (all bacteria), domain Archaea (consists of archeans), both Archaea and Bacteria
are prokaryotes. The third domain is Eukarya which contains all organisms composed of eukarytotic cells. Bacteria,
Archaea, and protists are no longer considered kingdoms
Terminology
• Unicellular
– Organism is only a single cell
• Multicellular
– Organism is made of many cells
• Cells are dependent on one another
• Autotrophic
– Photosynthetic Autotrophs:
• Heterotrophic
Terminology
Photosynthetic Autotrophs:
• use energy of sunlight and inorganic molecules to
make their own food (energy molecules)
• Photosynthesis
– Uses photosynthetic pigments
Terminology
• Heterotrophic:
– Break down organic molecules for food/energy
• eat other organisms (living or dead)—carnivores, herbivores,
scavengers, & decomposers
• eat wastes of other organism (detrivores & saprophytes)
Prokaryotes (e.g. Bacteria):
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small and simple
very diverse
very successful
found everywhere
– even extreme environments (boiling hot hotsprings, in ice, is super
salty water….environments that would kill plants and animals)
Fundamental Prokaryotic Characteristics:
they are small and simple
1.
2.
Very small (1/10 -1/1000 the size of a eukaryotic cell)
no nucleus (single circular piece of DNA is “unprotected”)
3.
lacks all organelles except ribosomes and simple cytoskeleton
4.
5.
have cell wall (for shape and protection)
Unicellular*
th
th
Prokaryotic
cell
virus
* usually, colonial forms exist
Typical
eukaryotic cell
Prokaryotic cell structure
Plasmid
“additional” DNA)
Additional Prokaryotic Features of Note
• Capable of rapid reproduction (once every 1-3 hrs, extreme cases
every 20 min)
»
»
from 1 to 1 billion (1,000,000,000) in 10 hours if they divide every 20 min
Makes them very adaptable
– binary fission
• Can transfer DNA from one to another
– conjugation
• Can absorb DNA from environment
– transformation
• Can form resistant endospores that stay dormant until
environment is good for growth again.
– Can even survive clean rooms, boiling, and outerspace
Binary Fission (how bacteria reproduce)
Cells copy DNA and then split into two
Categorizing Bacteria:
historically bacteria were categorized based on
• Shape
– Rods (bacilli)
– Spheres (cocci)
– Spirals (spirilli)
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metabolism
heterotrophic v. autotrophic
aerobic v. anearobic
DNA/genetics
YOU SHOULD BE ABLE
TO IDENTIFY THE
THREE SHAPES BY
THEIR OFFICIAL
NAMES
Lab utilizes/focuses on these
Importance/Relevance of bacteria:
be able to give some examples
• Environmentally:
– Decomposers/Nutrient Cycling
• Break down dead things to make nutrient available for other
organisms
– Nitrogen fixers/Nitrogen Cycle and Availability
• only organisms that can take atmospheric N2 and make it
available for use by other organisms
– root nodules
– crop rotation
– create oxygen (photosynthetic varieties)
– symbionte with other organisms
• e.g., gut fermentation
NITROGEN CYCLE -- nitrogen passes from physical environment to producers (e.g., plants) to animals, to
another animal (etc.) and returns to the physical env through waste and decomposition (of dead).
Importance/Relevance of bacteria:
be able to give some examples
• In human health
– pathogens
– “normal flora”
• prevent infections & can influence our immune system
• provide vitamins
• “pro-biotics” (e.g., Activia…you know the commercials)
• May alter immune function and be linked to autoimmune disorders and
allergies (hygenien hypothesis & old-friends hypothesis)
• May alter our fat deposition
– original source of some antibiotics
– Botox is made from bacterial toxin
– produce flatulents and B.O.
Importance/Relevance of bacteria:
be able to give some examples
• Food/Nutrition
Bacteria are used to chemical alter/change milk into things such as:
– yogurt
– kefer milk
– cheeses
– other fermented food items
that are more resistant to spoiling
• Some bacteria are pathogens to crop plants
Importance/Relevance of bacteria:
be able to give some examples
• Biotechnology:
Genetically engineered bacteria:
– production of drugs and/or hormones for human use
– Are being developed to production of ethanol (a fuel)
• Bioremediation
• gene mining for new substances and enzymes
– PCR/genetic analysis (e.g., DNA fingerprinting)
• assembling nanostructures (nanotechnology)
Protists are:
• Eukayrotic
• Can be unicellular or multicellular
• Can be autotrophic or heterotrophic
The “Mostly Heterotrophic” Protists
• Include:
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Paramecium
Amoeba
Euglena
Plasmosdium
• They are:
– Unicellular
– Mostly heterotrophic
– Have special structure for feeding and/or to make
them mobile
Protozoans:
Animal-like protists
Feeding and movement structures:
• cilia (ciliates)
• Flagella (flagellates)
• Psuedopods (ameobas)
Mostly Heterotrophic Protists
• You should know:
– The protists covered in the lab manual
– The structures each uses to feed and move with
– Any details about these from the lab manual that I
emphasized in lab
– Also know the two organisms that plasmodium must
pass through, the disease plasmodium causes, and
what parts of the human body it infects.
Euglena
Paramecium
amoeba
Protozoan Videos
Paramecium
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Generic views (1+min progressively zooms in on contractive vacule):
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https://www.youtube.com/watch?v=P6oHxbXKILw
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30 second close up where you can see feeding vacuoles move
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https://www.youtube.com/watch?v=jctNl30Cv_I
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Conjugation:
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https://www.youtube.com/watch?v=k1zAQqU1WQ0
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fission—turn off sound
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https://www.youtube.com/watch?v=vnlkvquWXS8
Amoeba
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General
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https://www.youtube.com/watch?v=o-PjvIRrbbw
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Feeding
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https://www.youtube.com/watch?v=pvOz4V699gk
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Euglena:
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https://www.youtube.com/watch?v=4MlR3dKfXmc
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flagellum
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https://www.youtube.com/watch?v=jl0TzaWUQWk
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amoeba meets Stentor (who loses?)
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https://www.youtube.com/watch?v=FcCvhYmjaXE
Algae:
plant-like protists
• Photoautotrophic:
– uses sunlight
• Can be unicellular (e.g., diatoms) or multicellular
• Traditionally classified by the color of photosynthetic pigment
– the molecule that captures the energy of sunlight
• Brown
• Red
• Green
Kelp Structure
Algae
You should know:
– The examples we looked at
– The structure of the “giant bladder kelp” and
the function of the holdfast, air cyst, and blade
– Know which are multicellular and which are
unicellular
– Give some examples of how Algae are
commercially important/relevant
Relevance of algae
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Base of aquatic/marine food chain
O2 production
Food for humans, e.g., nori
Commercial uses
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Agar gelatin (in scientific labs)
Source of Dyes/coloring agents
Thickening and stabilizing agents in foods, soaps, and cosmetics
Clarifying beer (“irish moss”)
Component of “personal lubricants”
• Potential source of biofuel
• Fertilizer
• Bioremediation (e.g.,uptake and remove phosphates)
Spirogyra (a green algae)
Diatoms a unicellular algae