The Prokaryotes (Eubacteria and Archeaea Flashcards
What are prokaryotes? (What kingdoms do they encompass?)
Single cell oragnisms.
Lack a nucleus, because they do not have membrane bounded organelles.
Typically the smallest organismsm on earth.
Kingdoms:
Eubacteria and Archea
What are the importance of prokaryotes? (There harmful effects on organisms)
-> Can cause many diseases in humans and in other organisms (From the perspective of the infected, it is harmful, from the perspective of the bacteria/prokaryote it is benefitual)
–> How is it benefitual for the prokaryote (Benefit environment, more food, etc,)
–> For certain prey (animals) it can be benefitual, because if the predators were attacked or infected with disease, they pray would live another day.
——-> Infection bacterias are considered pathogens (disease-causing agents, usuaing a virus or micro-organismsm [in this case a micro-organissm])
—> Affects more than humans, such as crops and live stocks.
—> By affecting one part of the food chain/kingdom, causes a domino affect.
–> Threatens our food supply.
How are prokaryotes benefitual towards the environment?
-> play a key role in recycling nutrients, as many prokaryotes act as decomposers or producers (Breaking down things to rebuild and reuse)
–> Help out with vital biogeochemical cycles such as the nitrogen cycle (Keeping things in balence)
-Photosynthetic bacteria (which belong in eubacteria and archea) are majour producers of atmospheric oxygen in marine environments.
How are prokaryotes benefitual towards humans?
-> Within the intestine of animals and humans (ie: ecoli, produces vitamin K and B12)
-Which is an example of mutalism and symbiosis
-Essenital to food production (yogurt, butter, cheese)
-Produces antibiotics (Can kill/weakan micro-organismsm)
-Usses and produces medically valuable componds (ie: insulin and human growth)
-Seweage treatment
-Odour control
-Digests organic matter and waste
—–> Within the human digestive system.
Whats the difference between antibiotics and vaccines?
Antibiotics fight bacterial infections, while vaccines fight viral infections.
What is eubacteria?
A kingdom, known as bacteria.
There are 6 different types of eubacteria with different features. However there are 8 main componets of the bacteria.
1) Prokaryotic
(Unicellular)
(No membrane bounded organnelles)
2) DNA structure = single loop, found in a region called a nucleoid.
–> The single loop is different from a humans DNA strand (not a double helix shape)
–> Not encomposed in a membrane or shell, freely flowing but is within an area (usually clumped up)
3) Has plasmids (one or many in its a cytoplasm)
–> Small loops of DNA, that contain a small # of genes, and is used to move around (used for reproduction)
–> These genes are not essential for cell function, however gives an advantage for cells.
4) Has ribosomes that are scattered throughout the cytoplasm (crutial for protein synthesis)
5) Has “pilli”
–> Similiar to villi and cillia
–> Help the cell attach to different surfaces and cells
–> Made up of stiff proteins
6) Has 1 or more flagellas
Tail-like structure fore movement.
7) Has a cell wall, made out of peptidoglycan
–> A large molecule that forms long chains, these chains are crossed linked, making the cell wall strong and rigid.
8) Has a capsule.
–> An outerlayer that provides protection for cells.
–> Why? The cells are very tiny, therefore needs as much protection as possible.
- SImilar to a membrane, helps reduce water loss and exposure to high temps.
9) All can reproduce asexually by binary finnision, some can reproduce sexually by conjunction
10) Mainly autotropic, some are heterotrophic
11) DOES not contain chloroplasts.
The structure of a typical bacteria cell?
Cell wall encompasses the layer of peptidoglycan and the cell wall, the outer wall has pilli, and plasmid is apart from the nucleoid.
What are the 3 types of bacterial shapes?
Cocci (singular - coccus) -Round
Bacilli (Singular - bacillus) -Rod shape (cylindar)
Spirill (Singular - Spirillum) -Spiral shape
All of these different shapes serve different functions.
Whats the function of the cocci/coccus shape?
-Resists drying
Whats the function of the bacilli/bacillus shape?
Allows the bacteria to absorb more nutriends due to greater surface area from the shape.
Whats the function of the Spirilli (Spirillum?)
Moves through fluids with the least resistance, “snake like”
When identifying bacteria, what are the prefixes used to group them/name them?
Prefix diplo-
Arranged in pairs
Prefix staphylo-
Arranged in clusters (like grapes)
Prefix strepto-
Arranged in chains/rod shaped
streptococcus pyogenes - strep throat
If the bacteria is on its own, use its singular name, NOT its plural name.
What are the two ways to identify bacteria?
Classifying bacteria VIA there cell wall
Classifying bacteria VIA respiration.
What is the Gram Stain?
Hans Gram discovered a method to classify bacteria, highlights the basic differences in the molecular arrangement in bacteriaal cell walls VIA dying the bacteria.
Differenciates between two majour cell wall types (Gram Negative) and (Gram Positive)
–> Method only works for eubacteria.
What does Gram positive bacteria mean?
Gram positive = contains more layers of peptidoglycan in the cell wall, staining purple.
What does Gram negative bacteria mean?
Gram negative, there is less layers of peptidogylcan in the cell walls.
Stains Pink or red.
–> Bacteria is still eubacteria, it just has less peptidoglycan.
Main differences between Gram + and Gram - ?
Gram +: Thick peptidogylcan layer, with no outer lipid membrane.
Gram -: Thin peptidoglycan layer, and a outer lipid membrane.
Classifying bacteria VIA respiration, what are the two main categories?
1) Aerobic bacteria
- Bacteria that can survive and grow in oxygenated environments (“Air a Robic”)
-
2) Anaerobic bacteria
-Bacteria that does not need oxygen to survive and grow
(ANA)
