Unit 2 Flashcards
What are the three different types of salt?
- Halotolerant
- Halophile
- Extreme Halophiles
What are Halo-tolerant salt characteristics?
Don’t like salty conditions but can TOLERATE it up to 10% and grow
What are Halophile salt characteristics?
Require some degree of salt to grow
What are Extreme Halophile salt characteristics?
Require 9% salt or HIGHER (Most are from, the group archaea)
What are nutritional factors that influence microbial growth?
Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur, Potassium, Magnesium, Calcium, and Iron
How does carbon distinguish the use of Eukaryotes?
Breaks Eukaryotes down to Heterotroph or Autotroph
What do Heterotrophs use?
organic carbon and consume organic manner for energy
What do Autotrophs use?
inorganic carbon (CO2 gas)
What are the two types of energy sources for Autotrophs?
Light = Photoautotrophs and Chemical = Chemoautotrophs
What sources do Photoautotrophs use and for what?
Plants, algae and cyanobacteria use H2O as an electron source to reduce CO2, producing O2 as a by product
Green sulfur bacteria and purple sulfur bacteria use H2S as an electron source; they do NOT produce O2
What sources do Chemoautotrophs use?
Hydrogen, sulfur, and nitrifying bacteria, some archaea (MOST BACTERIA ARE CHEMOAUTOTROPHS)
What are the two types of energy sources for Heterotrophs?
Light = Photoheterotrophs and Chemical = Chemoheterotrophs
What sources do Photoheterotrophs use?
Green non sulfur bacteria and purple non sulfur bacteria, some archaea
What sources do Chemoheterotrophs use/ process do they go for?
Aerobic respiration: most animals, fungi, and protozoa, and many bacteria
Anaerobic respiration: some animals, protozoa, bacteria, and archaea
Fermentation: some bacteria, yeasts, and archaea
Most pathogens are ________ pathogens but what is?
Not, “Helicobacter pylori”
What are some examples of Chemoautotrophs?
- Hydrogen bacteria
- Sulfur bacteria
- Iron bacteria
- Nitrifying bacteria
What is does Hydrogen bacteria do?
oxidize hydrogen gas (breaks it down to less toxic)
What does Sulfur bacteria do?
oxidize hydrogen sulfide (usually NOT a pathogen)
What are some examples of Sulfur bacteria?
Can be found in concrete water pipes, hot springs, and stagnant. (Smells like rotten eggs!)
What does Iron bacteria do?
Oxidizes reduced forms of iron
What is an example of Iron bacteria?
Can be found in soil and metal pipes
What does Nitrifying bacteria do?
oxidizes ammonia and nitrite
What are some examples of Nitrifying bacteria?
Found in the roots of plants, “seed” for septic tanks, and fish nitrifying bottles
Why do we want Nitrifying bacteria in the root of plants?
This bacteria will live symbiotically with plants. When plants get fertilized they put ammonia on the soil and the nitrifying bacteria
What is Helicobacter Pylori?
An organism in 1994 that was put on the Carcinogen list (which was huge because it was the first organism to be on this list.) This bacteria would burrow in cells and live within the mucus layer of the stomach and destroy it to create a “gap.” This gap would allow Gastric Juice to eat at the underlying layer causing ulcers and inflammation
What is a carcinogen?
An element that directly causes cancer
How do we get infected with Helicobacter Pylori?
We don’t know how we get infected by it or the transmission of it
What are the 5 central metabolic pathways?
- Breaking down glucose
- Glycolysis
- Pentose Phosphate Pathway
- Transition Reaction
- Citric Acid Cycle (AKA Krebs)
What are the goals of the central metabolic pathways?
- To create ATP
- Get NADH, FADH (reducing power, going to use these hydrogen ions to make more ATP)
- Precursor molecule (ending molecules)
What is important about Glycolysis?
- anaerobic process
- yields 2 ATP
- starting molecule is Glucose
- ends with 2 pyruvate molecules (precursor for Transition)
- Generates NADH (holds onto hydrogen ions)
- an alternate process for microbes for glycolysis is the Enter-Duodoroff Pathway
What is important about the Pentose Phosphate Pathway?
- Also occurs in our cells but has a much smaller role
- Has a big role in bacteria
- An alternate reaction to glycolysis but is half as efficient
- yields 1 ATP
- Gains NADH
What is important about the Transition Reaction?
- starts with Pyruvate
- ends with Acetal Coenzyme A (precursor for Citric)
- Generates NADH
What is important about the Citric Acid Cycle?
- Generate 2 ATP for EACH glucose molecule
- Also generates NADH and FADH (holds onto the high energy electron especially hydrogen)
What are the different names for the Citric Acid Cycle and why are there multiple?
Started as the Krebs cycle because of the first guy to recognize this process. It was named the Citric Acid Cycle to get away from naming processes after people. Then it has also been named Tricarboxylic Acid Cycle by microbiologist that noticed microbials also go under this cycle
what are the three major types of phosphorylation?
- Substrate level of phosphorylation
- Oxidative phosphorylation
- Photophosphorylation
What does Substrate level phosphorylation do?
Uses local energy (a molecule) to donate its phosphate to ADP. This requires a special enzyme. The Donor molecule needs to be organic. Doesn’t make a lot but cell can use it quickly. Also occurs in human cells.
What is an example of substrate level phosphorylation?
The donor molecule in glycolysis is Phosphoenol Pryuvic Acid.
Phosphoenol Pryuvic Acid + ADP + enzyme –> ATP
+ Pyruvic Acid
What does Oxidative Phosphorylation do?
Occurs at the ETC in the cytoplasmic membrane. Delivers the ions to the ETC AKA NADH and FADH which then drops off the hydrogen ion which is used to create Proton Motor Force. For every hydrogen ion a cell makes 1 ATP molecule. Can make a lot of ATP this way but needs OXYGEN for this process. O2 is the final electron acceptor. Also occurs in human cells.
What does Photophosphorylation do?
This process occurs in microbial cells ONLY and occurs in photosynthesis. Photoautotrophs go through this process. Microbe uses sun energy to generate (create high energy electrons). then it will take the electron and run them through the electron transport chain (ETC) to make ATP. In bacteria the ETC occurs in the cytoplasmic membrane. NAD and FAD pick up electrons in the citric acid cycle + glycolysis. The hydrogen ions were a part of glucose (organic molecules) and were liberated and broken up to make ATP. These organisms in photophos. use sun’s energy to create ATP and not from organic molecules. Uses Thylakoid structure.
What is a Thylakoid structure?
Structure located in the cytoplasmic membrane that allows photosynthetic microbes to harvest electrons from the sun’s energy
what are the final electron acceptors?
Oxygen, Other inorganic molecules (NO3, SO4, CO2), and organic molecules (Pyruvic acid)
What are the final electron acceptors for Aerobic respiration?
Oxygen
What are the final electron acceptors for Anaerobic respiration?
NO3, SO4, CO2
What are the final electron acceptors for Fermentation?
Pyruvic acid
What is fermentation?
The partial oxidation of sugars and other metabolites to release electrons. Uses organic molecules as final electron acceptor. Less efficient than respiration at making ATP
What are the three fermentation pathways?
- Lactic acid pathway
- Ethanol pathway
- Acetic acid pathway
What is the Lactic acid pathway?
Aspericillus, lactobacillus, or streptococcus ——> lactic acid ——–> cheese, yogurt, soy sauce
What is the Ethanol pathway?
Glucose ——> Pyruvic acid ——> Sacchromyers ——-> CO2, ethanol ———–> wine, beer
What is the Acetic Acid pathway?
Escherichia Acetobacter ——–> Acetic acid ——> vinegar
Where do we find DNA in bacteria?
Chromosomes in nuclei and plasmids (clump in cell)
What does the DNA in the nucleoid code for?
Codes for a protein to keep the cell alive
What does the DNA in the plasmid code for?
Toxins
What are the two types of gene transfer?
- Vertical Gene Transfer
2. Horizontal Gene Transfer
What does Vertical Gene Transfer do?
Bacteria replicate their genome and provide it to the next generation under binary fission. Bacteria can split into 2 daughter cells through this. Some recombination of the DNA occurs, but basically daughter cells are clones to mother cell. DNA goes from one cell to another.
What are the three types of Horizontal Gene Transfer?
- Transformation
- Transduction
- Conjugation
What happens during Transformation?
The Donor cell dies and releases DNA into the environment. The Recipient cell will take up the DNA, but when the cell dies the structures inside get degraded and taken up by a recipient neighbor cell. (like extra chromosomal fragments or plasmids) Recipient cell uses a special transporter molecule in to cytoplasmic membrane to move the DNA into its cell. Incorporates into its own geometry but needs non degraded DNA and something more it into its own geometry.
What is the purpose of Transformation?
To obtain new characteristics, doesn’t code for everything it may pick up something useless, ferments glucose, DNA codes for a certain molecule and makes insulin
What does Transduction do?
Relies on bacteria phages = virus that only infect bacteria
What are the two different types of Transduction?
- Lytic Replication
2. Lysogenic Replication
Lytic Replication
Bacteriophage inject DNA into cell which infects cell and hijacks cell and makes copies and degrades everything and make many viruses as fast as it can
Lysogenic Replication
Enables DNA into geome, DNA embeds in other DNA and replicates by binary fission into 2 cells. Vital DNA will make (genes in DNA) more bacteriophages and undergo the lytic cycle (make many more)
What is Conjugation?
DNA is transferred from a donor cell to a recipient cell via cell to cell contact using a conjugation pilus AKA protein tube. When bacteria uses these protein tubes they transfer plasmids. These tubes were created by donor cell and then dissolves. Only SOME bacteria uses this!
What is a dangerous strand of E. coli?
0157:H7
What shiga toxins were created by transduction of shigella and E.coli?
E. coli 0157:H7 and Shigella SP
What are antimicrobials?
Bacteria, Fungi, protozoa, viruses, helminths (aka worms)
what are antibiotics?
To kill or limit the growth of bacteria?
What are the 5 modes modes of action of antibiotics?
- Inhibit Cell Wall Synthesis
- Inhibit Protein Synthesis
- Inhibit Nucleic Acid Synthesis
- Interfere with Metabolic Pathways
- Interfere with Cell Membrane
What happens during Inhibit Cell Wall Synthesis?
Targets peptidoglycan layer to weaken the cell wall and the cell dies.
What makes the peptidoglycan break apart?
Beta lactam rings
What antibiotics contain a beta lactam ring?
penicillin, imipenem, cephalosporin, clavulanate
What bacteria is resistant to antibiotics with beta lactam rings?
- Staphyloccocus epidermis
- Pseudomonas aeruginosa
- Klebsiella pneumonia
- Escherichia coli
- Vancomycin
- Bacitracin
What happens during inhibition of Protein Synthesis?
Antibiotics bind to the ribosomes and PREVENT translation.
What are some antibiotics that participate in Inhibit of Protein Synthesis?
- Tetracycline
- Streptomycin
- Gentamycin
- Tobramycin
- Doxycycline
- Azithromycine
- Clindamycin
- Linezolid
- Dalfopristin
What happens during Inhibition of Nucleic Acid Synthesis
Antibiotics target enzymes required for nucleic acid synthesis
What are some enzymes antibiotics will target?
RNA polymerase, DNA, DNA gyrase
What are some examples of antibiotics that inhibit Nucleic Acid Synthesis?
Ciprofloxacin, Metronidazole, Rifampin
What does Rifampin do?
Has the ability to turn body fluids a different color (saliva, mucus, tears, urine, turns to a reddish orange)
What happens during interference with metabolic pathways?
Most all will interfere with FOLATE production in the bacteria
what happens during competitive inhibition?
Enzymes needed to make folate in the bacteria bind to the antibiotic instead of the molecules needed to make the folate
What are some antibiotic examples that interfere with metabolic pathways?
Sulfonamide (sulfa drugs) and Trimethoprim
What happens during the interference with Cell Membrane?
Causes the cells to leak; die
What are some antibiotic examples for interfering with the cell membrane?
Daptomycin and polymyxin
Where are these antibiotics mostly found?
on the skin
What does daptomycin target?
Kills Gran Positive cell
What does polymyxin target?
Kills Gran negative cell
How does bacteria resist the antibiotics?
- Drug inactivating enzymes
- Alteration of Targets
- Decreased Uptake of the drug
- Increased elimination of the Drug
How do Drug inactivating enzymes work?
Enzyme breaks down the antibiotic therefore it no longer works.
What are some examples of drug inactivating enzymes?
Chloramphenicol, acetyltransferase, beta lactamase
How does the alteration of targets work?
there is a minor structure change in the target of antibiotics, therefore antibiotics can’t bind to the target
What is an example of the altercation of targets?
A change in the rRNA
How does the decrease of uptake of drugs work?
Proteins in the membrane of the bacteria does not let the antibiotic cross and blocks the molecules from getting into the cell.
How does the increase of elimination of the drug work?
With the use of Efflux pumps the cells can pump the antibiotic out of the cell. Some bacteria can increase the number of Efflux pumps they have.
How does bacteria get the genes for resistance?
- Spontaneous mutation
2. Gene Transfer
How is spontaneous mutation obtained?
Through vertical gene transfer
What is spontaneous mutation?
Natural mutations that occur at a very low rate which could be the change needed to fight off an antibiotic. As cells replicate, natural mutations occur as a change in bases.
Most of the time these mutations do not result in ___________
resistance
How does Gene transfer occur?
Through horizontal gene transfer (all three types)
Where does Gene transfer occur?
Most common occurrence is in the conjugation of R-Plasmids which carry the gene for resistance of many types of antibiotics. Genes that code for resistance may be shared /w a different strain or species
What are the clinically significant bacteria that have resistance?
- Family Enterobacteriacea
- Genus Enterococcus
- Staphylococcus aureus
- Streptococcus pnuemoniae
- Mycobacteriumm tuberculosis
- Clostridiodes
What is an example of spontaneous mutation?
A single base pair change in a gene that codes for the ribosome (rRNA)
What are some examples of overuse with antibiotics
- Prescribing antibiotics when bacteria ISNT caused by bacteria
- Including antibiotics in livestock animal food
- Virus, fungi, etc.
What is an example of misuse of antibiotics?
Not taking the antibiotic as directed like stopping to early
What is wrong with the following statement? :
My body has become immune to the antibiotic.
Instead of “my body” it would be The bacteria, and instead of “immune” it should be resistant. Immune insinuates it deals with T-cells and B-cells which are against pathogens. Not all bacteria are pathogens
