Bio 1215 Prokaryotes
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What are prokaryotes?
- - the most prmitive organism on earth
- - are unicellular
- - are the smallest living organisms
- - lack membrane bound organelles
What is a cell wall function?
- 1. to offer protection from viruses
- 2. maintain cell shape
What is the difference between cell wall of bacteria verses cell wall of plants
1. Cell wall of bacteria contains peptidoglycan which mains the cell wall very rigid, it is not very permeable, it is there to protect cell wall from turgor pressure
- 2. The plant cell wall is made up of cellulose, a polymer of glucose and is
- used to give structural support to the cell. In addition the cell wall
- is used as a filtering mechanism and also helps to expel excess water.
(T)How do antibiotics selectively destroy bacteria? Be specifc.
The antibiotic penicillin is able to kill bacteria by preventing the cross-linking of peptidoglycan and this causes the cell wall to weaken and lyse. The lysozyme enzyme can also damage bacterial cell walls.
Penicilliin turns off enzyme that makes peptidoglycan and so it cannot grow/divide so no making of cell wall. Cell wall becomes too thin in structure that it eventually pops!
How is Ribosomes in bacteria unqiue in structure?
It has a different chemical composition. Its smaller than our ribosomes and is very specific.
How does DNA have a unique structure?
It has a single strand of DNA double helix, but the 2 ends connected together. Its only 1 DNA molecule in one bacterium compared to our cells that have 46 DNA molecules.
What does streptomycian do?
It targets ribosomes of bacteria so therefore the ribosomes cannot make any more proteins so it shuts off.
What is a capsule and what is its functioN?
Capsule is a slimy polysaccharide or protein coat. It allows bacterium to attach/cling on to places. Can absorb nutrients from cells. (adds another layer of protection)
What is fimbriae? and its function?
Fimbriae are numerous protein containing, hair-like projections. Its sticky and allows bacterium to attach/cling on to places. Can absorb nutrients from cells. Usually in testinal tract.
What is a flagellum and capare prokaryotes/eukaryotes flagella
Flagellum is stiff, corkscrew-shaped protein attachments that rote to propel them forwards.
Eukaryote flagella: Has plasma membrae around it, has a 9 + 2 arrangement of microtubules, like sperm movement, straight,flexible and moves back and forth(whip like)
Prokaryotes flagella: Prokaryotes may have one or many flagella for locomotion. Bacterial flagella are entirely outside the cell membrane (plasma membrane) and are normally visible only with the aid of an electron microscope.
What are endospores? And its function?
Endospores consist of a copy of the genetic information surrounded by a thick, protective wall.
- Bacterial endospores serves the survival of the bacteria.
- The bacteria will change form into an endospore when conditions for
- survival is unfavorable. In this state they are hardier, resist many
- environmental changes, require no nutrients or water and can survive
- undetermined periods of time (it is believed it may survive thousands of
- years). Once survival conditions becomes favorable, it reverses it's
- form to normal bacterial form and restart division cycle. For us, is a
- real pain to get rid of, but for the bacteria, it's a major tool for
What 6 structure is prokaryotes make up of?
Ribosomes, DNA, cell wall, capsule, flagellum, endospores
(T)What is binary fission?
RAPID. A type of asexual reproduction common among prokaryotes wherein a cell divides giving rise to two cells, each having the potential to grow to the size of the original cell.
- Basically, it multiplies the bacteria into more copies.
- 1. ONE Circular DNA molecule is copied
- 2. Hook the DNA up to membrane
- 3. Creates membrane inbetween two DNA molecules
- 4. The membrane pinches off in between until it splits in two.
How is the separation of the copies of the genetic material of prokaryotes different from eukaryotes?
Bacteria has no microtubules so the genetic material of bacteria splits in two.
(T)What is conjugation? Explain.
Its like bacterial sex. Conjugation is the transfer of a copy of a small, ciruclar DNA molecule(Plasmid) through a tube-like "connection" (pilus) from one bacterium to another.
One bacterial cell that contains plasmid(which could code for resistance for antibiotics) would be the donor. It is like the Male who is the donor has sex with a female and the DNA material transfers through to the female and once it goes through synthesis and such, the female becomes a male. They all become (donors). It only goes in one direction so one gets the benefit and the other doesnt.
Whats the benefit of conjugation?
- 1. Genetic variation(all sex is about)
- 2. New strains of bacteria
(T)What are the three classifications of prokaryotes based on arrangement?
- 1. Diplo- exist in "pairs"
- 2. Strepto - exist in "chains"
- 3. staphyo - exist in "clusters"
Ex. Diplobacilli (Rod shaped, has not gone through through binary fission completion)
Streptococci: spherical (throat infections)
Staphylococci: divided by binary fission
Explain the difference between structure of gram-positive bacteria, and gram negative bacteria.
Gram posiitive PURPLE, gram negative PINK
Gram positive= thick outer layer of peptidogylycan and plasma membrane inside.
Gram negative = peptidoglycan cell wall in between outer liposolysaccharide membrane layer and plasma membrane on inside.
Why does gram positive bacteria stain purple?
Because it has a thick cell wall
WHy does gram negative bacteria stain pink?
Because it ahs thin cell wall and 2 plasma membranes
(T)Why is gram negative more dangerous than gram positive bacteria?
- 1. Gram negative has 3 layers of protection!
- 2. the lipopolysaccharide outer layer is very poisonous.
What are the basic steps of gram staining?
- 1. We use purple crystal violet to stain the bacteria.
- 2. WE use alcohol to take out the stain (Gram negative loses colour faster than gram positive because of thin cell wall)
- 3. Saffranin is used as a counter stain to stain the gram negative cell.
What is Heterotrophic Prokaryotes?
It breaks down organic material of "OTHER" organisms.
(T)What is obligate aerobes?
Able to surive in presence of oxygen.
(T)What are obligate anaerobes?
Able to survive in absence of oxygen.
(T)What is facultative anaerobes?
Able to grow/survive in absence OR presence of oxygen
(T)What are saprophytes?
It decomposes, breaks down dead waste materials ex. corpses. used for sewage treatment.
(T)What are parasites?
They cause sicknesses and feed on host cells.
What are photoautotrophic prokaryotes? Give example.
They make their "own" organic matter using "sunlight" and in the process release oxygen. Ex. Cyanobacteria = make oxygen used for "reducing armpit sweat etc"
Why were photoautotrophic prokaryotes important in the history of earth?
They raised the oxygen levels which then incrased our diversity of animals in our planet.
What are chemoautotrophic prokaryotes? Give an example
They oxidize inorganic compounds(no carbons) such as hydrogen sulfide(H2S) and ferrous ions (FE2+) to obtain their energy.
Ex. clostridium notulism (Used for botox) Most toxic dangerous , targets diaphragm muscles.
What are the 5 types of heterotrophic prokaryotes that breakdown organic material of "other" organisms?
- 1. obligate aerobes
- 2. obligate anaerobes
- 3. facultative anaerobes
- 4. saprophytes
- 5. parasites
What are the three types of classifcation of prokaryotes based on metabolism? and which one is only found in prokaryotes?
- 1. heterotrophic
- 2. photoautotrophic
- 3. chemoautotrophic
CHEMOAUTOTROPHIC only found in prokaryotes
(T)What are three diseases caused by prokaryotes?
- 1. lymp disease
- 2. necrotizing fasciitis "flesh eating disease"
- 3. tetanus
What is lyme disease caused by? and who carries them? and what are the symptoms?
Lyme disease caused by spirochette bacterium carried by ticks. Divides by binary fission
Symptoms: red rash where tick bites, red circles like bullseyes, arthitritus/joint problems. If not treated affects central nervous system and neurical system problems
(T)What are the 5 characteristics of a spirochete bacterium?
- 1. flagellum between cell-wall
- 2. spiral shape
- 3. rotates as it moves
- 4. corscrew shaped
- 5. cell wall flexible
What is necrotizing fasciitis "flesh-eating disease" caused by? and what is its symtoms?
Caused by a streptococcai bacterium. caused by CUTS, nonsterile sugical equipment (endosphores of bacteria), the toxin in the causes the problem(found in soil), destroys blood vessels/skin/muscles
Give some characteristics of a streptococcal bacterium?
Sperical shaped and found in chains
What is tetanus caused by? and symptoms?
Caused by obligate anaerobic bacillus bacterium that thrives in deep wounds.
Usually happens in construction sites cause there are a lot of nails.
Muscles contract and don't go back. Muscle stiffness. Some people break bones and get spasms, usualy die. Can't be fed. It acts on the "motor" neurons
Give characteristics of obligate anaerobic bacillus
can't survive with oxygen, rod shaped
(T)What is nitrogen fixation?
Nitrogen fixation is carried out by bacteria in root nodules.
Nitrogen fixation is the natural process, either biological or abiotic, by which nitrogen (N2) in the atmosphere is converted into ammonia (NH3). This process is essential for life because fixed nitrogen is required to biosynthesize the basic building blocks of life, e.g., nucleotides for DNA and RNA and amino acids for proteins. Nitrogen fixation also refers to other biological conversions of nitrogen, such as its conversion to nitrogen dioxide.
What do prokaryotes do for plants?
Prokaryotes breakdown the cellulose of plant cell walls in the digestive tract of herbivores
(T)What is the role of bacteria in our digestive tracts?
1. The bacteria produces cellulose and breaks it down to glucose.
2. Make Vitamin 12(maturing of RBC) and for vitamin K(bloodclots)
What is the purpose of bioluminescent prokaryotes that live witnin organs in deep sea marine life?
- 1. to attract mates
- 2. to attract food (by other animals being attracted by the lights)
What is vitamin B12 for?
TO make Red blood cells mature fround a round circular shape to mature sexy curve shape. The nucleus disapears in the red blood cells and changes shape to sexy so it can easily squeeze through capilleries. (Increase in Surface area)
Why do herbivores need bacteria in their digestive tract?
Since animals can't break down cellulose, they eat plants that contain bacteria that breakdown the cellulose of plant cell walsl in our digestive tract to glucose.
(T)What is bioremediation?
- Bioremediation can be defined as any process that uses microorganisms or
- their enzymes to return the environment altered by contaminants to its original
Use micro organisms to NATURALLY clean up pollutants
What is the ecological importance of saprophytic bacteria?
saprophytic bacteria are decomposers that release nutrients and recycle the nutrients . Decomposes dead bodies.
What do bacteria do to milk products?
They convert milk sugar (lactose) to lactic acid to produce the sour flavour of yogurt and pickles, and the flavors of many cheeses.
Why are prokaryotes important?
- 1. used in bioremediation (ex. decomposition of oil spills)
- 2. produce antibiotics
- 3. use in commerical foods milk products
Why do bacteria produce antibiotics?
To protect themselves, getting rid of competitiors around them
Explain how the decomposition of oil spills work?
They spray phosphate and nitrogen which encourages bacteria on the rocks which then causes binary fission encouraging natrual bacteria that destroys oil
(T)Explain the steps of biological engineering in prokaryotes
- 1. Desired geen is inserted into a plasmid
- 2. plasmid is inserted into a bacterium
- 3. bacterium divides by binary fission and makes multiple copies of the gene
- 4. the gene can be inserted into plants to make them resistant to poilage and disease
- 5. the gene can be used to alter bacteria for cleaning toxic wastes
- 6. the gene canbe expressed to produce a protein for the treatment of a disease Ex. growth hormone for dwarphism
What are the uses of biological engineering in prokaryotse?
- 1. Gene can be inserted into plants to make them resistant to spoilage and disease
- 2. the gene can be used to alter bacteria for cleaning toxic wastes
- 3. the gene can be expressed to produce a protein for the treatment of a disease
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