Microbiology EXam 2
Last Modified: 2011-07-10
micronutrients (Zinc, copper and magnesium) that occur in small amounts and are involved in enzyme function and maintenance of protein structure. They are non fastidious organisms (meaning they don’t require special nutritional or environmental conditions for growth)
Carbon, Hydrogen, Oxygen, Phosphorus, Nitrogen, Sulfur, and Iron. All living things require these elements.
only required for fastidious organisms (organisms that require special nutritional or environmental conditions for growth)Example: nisseria gonorea- needs amino acids. 1. Amino Acids 2. Purines 3. Pyrimidines
Agar is a polysaccharide. It is heat stable meaning it can be heated up and it still works. Nutrients have to be placed in the agar.
-complex media- used in lab. We don’t know the exact chemical composition.
- inhibits growth of one bacteria over the other. For Example: MacKonkey is selective for gram negative and Mannitol Salt is selective for gram positive.
distinguish one microorganism type from another growing on the same media. MacKonkey is differential for lactose fermentation and mannitol salt agar is differential for mannitol fermentation.
microorganisms that live and grow in the absence of molecular oxygen. They gather at the bottom of the test tube to avoid oxygen. They do not have enzymes, and lacks an electron transport chain- that is why we can’t use oxygen. These form endospores so they are also thermophiles.
not obligate.The anaerobe does not need oxygen to grow. Lack of oxygen does not hurt them, they can be found all along the test tube.They are adapting to variations.Have both enzymes (superoxide dismutase and catalase). Example: E. Coli and S. aureus
- they require oxygen but at a low concentration. So they will gather at the upper part of the test tube but not at the bottom. Has little enzymes.
Example: Helicobacter Pylori – also a neutrophile and makes an enzyme called Urease which changes the pH of 3 to 7 so it can survive in the stomach. Causes Ulcers.
oxygen-needing bacteria. Gather at the top of the test tube in order to absorb maximal amounts of O2. Has enzymes.Survival depends on their ability to detoxify O2 and successful gene expression.Ex: Bordetella Pertussis- causes the whooping cough.
are not affected at all by oxygen; they are evenly spread along the test tube. They only contain the enzyme superoxide dismutase. Use Peroxidase to break down peroxide and superoxide.
1. Superoxide Dismutase- removes the free radical from oxygen making O2 and H202(Hydrogen peroxide).
2. Catalase- turns H2O2 into O2 and H2O so now it can safely go into the body.
a site on the chromosome that provides information for a certain cell function.
not clear what it does but its thought to synthesize ribosomes. A single-stranded transcript that is a copy of part of the DNA template.
adds new nucleotides to a new strand of DNA modeled after an old strand of DNA. It is also for proofreading. Note that the nucleotides are not stable because DNA ligase has not been applied yet.
addition or deletion of one or more bases
CGC GGT ---- > CGC
happen all the time. Results from exposure to known mutagens
set of gene’s that’s turned on, so this means they are initially off. These are genes we don’t need.
Example: cancer cells
1. Catabolite activating protein (CAP)
2. CAMP (cyclic)
So if there is no glucose present then the these secondary messengers are high. If glucose is high then they are low because the lactose operon doesn’t need to be turned on.
set of gene’s that are turned off. We need these genes, they are always on. They are controlled by a repressor. The repressor is not bound to the operator (so it is on) so we have to make the repressor bind to the operator to turn it off.
use living organisms to produce useful products to solve a problem. “invivo” testing- using a rat or some type of animal.
use biological molecules to produce useful products or solve a problem. “invitro” testing- using a test tube with bacteria cells or human cells.
more specific terms of biotechnology. Manipulate the genes of an organism.
Recomboniant DNA technology
1. Restriction Enzymes- enzymes that recognize and cut DNA sequences. They learn things from bacteria cells.
2. Plasmids- genes that can make bacteria resistant to antibiotics and can express genes from foreign organisms.
2. R-Plasmid, R-resistance. Carry antibiotic resistance and are self replicating.
3. DNA Ligase- seals in the gene.
- Gene library-cloned DNA stored in yeast, viruses, or bacteria.
- Polymarase Chain Reacton(PCR)-amplify DNA.
- DNA Fingerprinting-analyze DNA/associated with replication.Forensics, Paternity testing, Diagnostics
- Human Genome Proj
Acidophilus- makes lactic acid to keep eurogenital tract low.
Both of these are good bacteria cells that keep you from getting a yeast infection.
Methods of handling microbial cultures, and patient specimens in a way that prevents infection of the handler and others who may be exposed.
Ex: Sanitization,Disinfectants, Antiseptics-growth-inhibiting agent used on tissues to prevent infection.
Cluster of genes that regulates metabolism by controlling mRNA production.
- Promotor- where RNA polymerase binds to start transcription. DNA sequence
- Operator- a repressor binds to block transcription. On/Off switch. DNA sequence
- Structural Genes- encode for a set of enzymes.
a safe level free of viable pathogenic microorganisms but is not sterile. You still may see microbial growth including endospores.
grow at intermediate temperatures, warm loving.37degrees C.
Ex: staph aureus
Bactericidal and aseptic, because endospores can survive in too basic or too acidic condition.
- Acidophile- likes pH3
- Neutrophile-likes pH7 (our bodies are kept at 7)
- Alkalophile-likes pH9
.01um- for bacteria and viruses
.10um- for bacteria and viruses
.22um- for bacteria but not viruses
.45um- some bacteria but mainly dirt
interfere with proteins and the plasma membrane. (mode of action)
- water availability
mRNA- 5'-3', so the 3'-5' from DNA is what we have to use because it is the opposite.
tRNA- 3'-5' because it is the opposite of mRNA
- Metabolism- looking at by products. CO2 and ATP are measured.
- Dry Weight- wet solution
- Turbility- cloudiness in the test tube
Clostridium Perfringens- causes gangrene
Clostridium tetini- tetanus
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