Microbio Exam three

Definition of Infection?

Results when pathogens overcome the body’s external defenses, and multiply and become established in the body

Definition of disease?

results when an injury is significant enough to interfere with the normal body function of the hosts body

4 types of Symbiosis?

Mutualism - Benefits both organisms

Commensalism - Benefits one but doesn’t help or hurt the other

Parasitism - Benefits the parasite while being harmful to the host

Amensalism - One is harmed while the other is neither helped or hurt

Types of normal microbiome microflora?

Resident Flora - always there

Transient Flora - never there for more than a few hours

Opportunistic Pathogens - wrong place wrong time

Definition of Etiology?

the cause of a disease

What are the steps Koch took to determine particular pathogens?

* A blood sample was collected from a cow, and observed and cultured them
* Inoculated a susceptible host which died via the same symptoms as the original host
* Took another blood sample which matched the original

4 Requirement to determine if a pathogen causes disease?

* Same pathogens must be present in every case of the disease
* The pathogen must be cultured and isolated
* The cultured agent must cause disease when inoculated with a healthy host
* The same agent must be isolated from the disease experimental host

Definition of environmental Microbiology?

Study if microorganisms as they occur in their natural habitats

Definition of Microbial Ecology?

Study of the interrelationships among microorganisms and the environment

Definition of Biodiversity?

Number of species living within an ecosystem

Definition of Biomass?

Mass of all organisms in an ecosystem

Levels of microbial Association?

* Population - all members of a single species
* Guilds - populations of microorganisms that perform metabolically similar processes
* Microbiome - Community of all microbes in one location
* Microhabitats - Small spaces where the condition are optimal
* Ecosystem - Groups of microhabitats in which organisms interact
* Biosphere - All ecosystems are made of many habitats

What is Bioremediation?

The use of microorganisms to clean up toxic, hazardous compounds by degrading them to harmless ones

What are the phases of culture growth?

Log Phase - Bacteria start to grow

Exponential Phase - Population doubles every twenty minutes

Stationary Phase - Growth stops

Death Phase - Bacteria die faster than they multiply

Horizontal Genetic Transfer - Transformation

* Don’t reproduce sexually
* Naked DNA fragments are brought in and put together when inside the recipient cell

Horizontal Genetic Transfer - Transduction

* phage attaches and injects DNA which is used to make new phages that inject their DNA into the recipient host cells

Horizontal Genetic Transfer - Conjunction

* rolling circle and replication
* virulence plasmids (which contain genes that increase pathogenetically)
* Multidrug resistance plasmids
* multi antibiotic resistance gene

Explain central dogma.

DNA is transcribed into RNA and translates that into proteins, and DNA can also replicate other DNA

Who created the central dogma and in what year?

Francis crick and 1962

Explain the Glycolysis.

Energy-investment Stage:

* A cell invests the energy in two nutrients molecules of ATP by phosphorylating a glucose molecule and rearranging in atoms to form fructose 1,6 bisphosphate

Lysis Stage:

* The cell lyses fructose 1,6 bisphosphate into G3P and DHAP. DHAP is converted to G3P so the cell has two molecules to end the stage

Energy Conserving Stage:

* The cell oxidizes the two molecules of G3P to pyruvic acid, thus creating two ATP molecules

Describe pre-Krebs cycle

Pyruvate moves inside the mitochondria and gets oxidized and transfer electrons and hydrogen to NAD+ creating NADH, which is an electron carrier. The pyruvate breaks down and releases CO2, and Acetyl CoA will be fed into the Kreb Cycle

Describe Krebs Cycle.

Acetyl CoA reacts with a four-carbon molecule called oxaloacetate and they react forming a six-carbon molecule called citric acid. It gets oxidized and transfers electrons to NAD+ forming NADH. This releases CO2, and there remains a five-carbon molecule that goes through the same process again, forming a four-carbon molecule. Those four carbon molecules undergo a reaction and release something that joins ADP and phosphate to form ATP. The molecule gets oxidized and transfers those electrons and hydrogens to FAD, forming FADH2, which will carrier electrons to the electron transfer chain

Describe the Electron Transfer Chain

NADH arrives to the first protein in line on the bilayer and FADH2 arrives to the second. As they drop off their original NAD and FAD forms via redox reactions, Electrons are passed from one protein ti the next until they reach the end where they will join oxygen and hydrogen to form water. The energy is produced by the movement of electrons pumps hydrogen protons across the bilayer creating the protein gradient. The protein gradient propels hydrogen protons down a protein pump called ATPase which in turn creates ATP via phosphorylation. This process is referred to as chemotaxis which is the use of ion gradient to produce ATP

Describe Fermentation

If oxygen levels are not optimal pyruvate during glycolysis cant continue on the Krebs cycle instead pyruvate splits in lactic acid and acetaldehyde. During the splice a decarboxyl reaction and the loss of CO2 result into acetaldehyde and a redox reaction in which NADH is reduced to NAD and produces lactic acid.

What is Catabolism?

breaks molecules by separating bonds which releases energy trapped in bonds

What is anabolism?

Metabolic pathways that construct bonds, requiring energy.

What is an enzyme cofactor?

molecules required to activate enzyme; store electrons 

substrate-level phosphorylation

The formation of ATP and unstable covalent bond by directly transferring a phosphate group to ADP from an intermediate substrate in catabolism

Bacterial Chromosome replication 

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1\. DNA synthesis begins at the origin of replication

2\. synthesis of DNA proceeds bidirectionally around the bacterial chromosome

3\. the two replication forks meet at opposite side of chromosome, ending replication

DNA Replication

DNA unzips into two parts and splits with the cell. In it's new home each side of the DNA strand attach to matching nucleotides to create 2 exact copies. Read template 3 to 5 but, synthesize 5 to 3. 

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Commensals 

organisms living in a close relationship in which one benefits from the relationship, and the other neither benefits nor is harmed

What is the Shine-Dalgarno sequence?

* 16s rRNA
* Ribosome sites
* A - Aminoacyl (enter site for new amino acids
* P - peptidyl (Where peptide bonds form
* E - Exit site (Exit site where empty tRNA leaves)
* Binds with complementary 16S rRNA and binds two strands and the subunits together
* 3 base codons on a strand of mRNA few bases a few bases before the start codon. It attracts ribosomal subunits to the strand and aligns them with the start codon so that translation can occur

Transcription - initiation

RNA polymerase attaches to DNA and travels until it recognizes the promotor sequence. Once the promotor is recognized the RNA polymerase unzips the DNA molecule beginning at the promotor

Transcription - Elongation

Triphosphate ribonucleotides align with their DNA complement and RNA polymerase links them together, synthesizing RNA. Also provides the energy required for RNA synthesis

Transcription - Termination

Self-termination- Transcription of DNA terminator sequences causes the RNA to fold, loosening the grip of polymerase on DNA.

Enzyme-dependent termination - Pho pushes between polymerase and DNA, releasing polymerase, RNA Transcript and rho

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