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

TerminologyPhotosynthetic 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):

• 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. Very small (1/10th-1/1000th the size of a eukaryotic cell)

2. no nucleus (single circular piece of DNA is “unprotected”)

3. lacks all organelles except ribosomes and simple cytoskeleton

4. have cell wall (for shape and protection)

5. Unicellular*

* usually, colonial forms exist

Typical eukaryotic cell

Prokaryotic cell

virus

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)

• metabolism• heterotrophic v. autotrophic• aerobic v. anearobic• DNA/genetics

Lab utilizes/focuses on these

YOU SHOULD BE ABLE TO IDENTIFY THE THREE SHAPES BY THEIR OFFICIAL NAMES

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/NutritionBacteria 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:– 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 VideosParamecium•Generic views (1+min progressively zooms in on contractive vacule): •https://www.youtube.com/watch?v=P6oHxbXKILw •30 second close up where you can see feeding vacuoles move•https://www.youtube.com/watch?v=jctNl30Cv_I•Conjugation:•https://www.youtube.com/watch?v=k1zAQqU1WQ0•fission—turn off sound•https://www.youtube.com/watch?v=vnlkvquWXS8

 

Amoeba •General• https://www.youtube.com/watch?v=o-PjvIRrbbw•Feeding•https://www.youtube.com/watch?v=pvOz4V699gk• 

Euglena:•https://www.youtube.com/watch?v=4MlR3dKfXmc•flagellum•https://www.youtube.com/watch?v=jl0TzaWUQWk• 

amoeba meets Stentor (who loses?)•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

• Base of aquatic/marine food chain• O2 production• Food for humans, e.g., nori• Commercial uses

– 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