Bacteria Structure & Classification (MICROBIO Exam 2)

Phototrophs

Derive energy from light

Oxygenic photosynthesis

Requires water, produces oxygen

Anoxygenic photosynthesis

Requires inorganic compound, produces an inorganic element

What is an example of bacteria who use oxygenic photosynthesis?

Cyanobacteria

What is an example of bacteria who use anoxygenic photosynthesis

Sulfur and iron bacteria

What are sulfur and iron bacteria used for?

Bioremediation (remove or lessen environmental pollutants)

Chemotrophs

Derive energy from breaking chemical bonds

Methanotrophs

Use metabolism as an energy source

Diazotrophs:

Use nitrogen as an energy source

Nitrogen fixation:

Conversion of atmospheric nitrogen to ammonia

Nitrification:

Nitrate produced from ammonia

Denitrification:

Regeneration of atmospheric nitrogen

Nitrogen assimilation:

Use of nitrogen for amino and nucleic acids

What are the 5 steps of binary fission?

1. Attachment site forms

2. Nucleoid duplicates

3. Cell elongation

4. Cross wall forms

   1. Cross wall seperates

Attachment site

The point where the DNA is connected to the cell membrane

Cross wall

Point where 2 replicated cells split off

What are the 6 steps of endospore formation?

1. Nucleoid duplicates

2. Forespore forms from mother cell

3. Mother cell engulfs - endospore

4. Endospore forms cell wall and membrane

5. Mother cell dies

   1. Free spore

When are endospores formed?

In times of nutrient deficiency

What are the differences between DNA replication in prokaryotes and eukaryotes?

Prokaryotes: Circular DNA, simple replication, less enzymes needed, one origin of replication

Eukaryotes: Spiral DNA, complex replication, more enzymes needed, multiple points of replication

What are the 4 steps of conjugation?

1. Donor cell attaches pilus to recipient cell

2. Plasmid is nicked and unwound by relaxosome

3. Strand of DNA is transferred via transfersomes

   1. Plasmid DNA is duplicated within each cell

What is natural transformation?

Dead bacteria rupture in the cell, releasing their DNA in the environment for other cells

What are the 4 steps of recombinant DNA?

1. Plasmid vector is selected

2. Plasmid is nicked with endonuclease, attaching to sticky ends

3. Plasmid and gene of interest are joined by ligase

   1. Recombinant DNA made

TRP operon: low tryptophan concentration

Continues to transcribe tryptophan

TRP operon: High tryptophan concentration

Stops transcribing tryptophan

When is the lac operon turned on?

When the inducer (lactOSE) is present

When is the lac operon turned off?

When the inducer (lactOSE) is absent

What does the lac operon produce?

lactASE

What allows bacteria to have a distinct shape?

Reproductive organization

What type of bacteria forms endospores

Bacillus

Spirochetes:

Spiral bacteria: common, flexible, endoflagella

Spirillum:

Spiral bacteria: Multiple flagella, rigid

Vibrio:

Spiral Bacteria: Curved rod, spiral flagella

Gram Positive VS Gram Negative

Positive: Thick peptidoglycan layers, acid chains, produce a dark purple color

Negative: Thin peptidoglycan layers, lipopolysaccharide chains, produce a light red color

Are proteobacteria gram positive or negative?

Negative

What are the pathogenic and nonpathogenic forms of proteobacteria?

Pathogenic: E. Coli, Salmonella, Y. Pestis, V. Cholerae, and N. Meningitidis

Non Pathogenic: Nitrogen fixing bacteria, some E. Coli

What is the shape of E. Coli?

Bacillus/Rod

How do the nonpathogenic forms work?

Normal gut flora, microbes live in your intestines

Pathogenicity of UTIs

Adhere to the urinary tract via pili and sugar receptorsPa

Pathogenicity of gastroenteritis

Enterotoxins cause water movement in intestines, resulting in cell death

What is the shape of Cholera?

Vibrio/Macaroni

What is the pathogenicity of Cholera?

Interacts with adrenaline receptors, which causes chlorine to be flushed into your intestine, causing diarrhea

What causes cholera and how do you treat it?

Contaminated water; can be treated with rehydration

What is the shape of Pestis?

Coccobacillus

How does Pestis spread?

Fleas

Pathogenicity of Pestis

Suppresses immune system and grows inside the immune system

How can we treat Pestis?

Antibiotics

Are firmicutes gram positive or negative?

PositiveW

What are the pathogenic and non-pathogenic forms of firmicutes?

Pathogenic: Clostridium, Staphylococcus, Mycoplasma, some Bacillus

Non-pathogenic: Lactobacillus, some Bacillus

What is the shape of lactobacillus?

Bacillus/Rod

What are lactobacillus used as?

A probiotic

What is the shape of staphylococcus?

Coccus/Circle

How do non-pathogenic forms of staph work?

Live naturally on your skin

What are the 2 enzymes involved in the pathogenic staph?

Coagulase and Protease

Coagulase

Causes blood to clot

Protease

Breaks down tissue

What shape is botulism?

Bacillus/Rod

Botulism Toxin:

Causes FLACCID paralysis, leading to respiratory failure

How can botulism be treated?

Antitoxins

What is the shape of tetanus?

Bacillus/Rod

Tetanus Toxin:

Causes SPASTIC paralysis, leading to respiratory failure

Are actinomycetoma gram positive or negative?

Positive

What makes the bacteria in Actinomycetoma heat resistant?

Made up of 70% guanine and cytosine

What are non-pathogenic forms of Actinomycetoma used for?

Making antibiotics

What shape is tuberculosis?

Bacillus/Rod

How is tuberculosis spread?

Respiratory droplets

What makes tuberculosis water and drug resistant?

Mycolic acid

What is the pathogenicity of tuberculosis?

Bacteria is isolated in the immune system, inhibiting antimicrobial activity

Are Spirochaetes gram positive or negative?

Negative

What is the pathogenicity of Spirochaetes?

Hemolysins form

Why does syphilis occur in stages?

It evades the immune system, hides, and remains dormant

What do cell wall antibiotics do?

Prevents the formation of cell wall

What are cell wall antibiotics effective against?

Gram positive bacteria; staph, strep, syphillis

Examples of cell wall structure antibiotics:

Penicillin, bacitracin

What do DNA antibiotics do?

Damages bacteria DNA, preventing replication

What are DNA antibiotics effective against?

UTIs, pneumonia, and gonorrea

What are examples of DNA antibiotics?

Nitrofurantoin and Ciprofloxacin

What do transcription antibiotics do?

Bind to RNA polymeraseWh

What are transcription antibiotics effective against?

Gram positive bacteria, tuberculosis

What do protein synthesis antibiotics do?

Inhibits translation by binding to tRNA

What are protein synthesis antibiotics effective against?

Spirochetes, chlamydia, tuberculosis, and malaria

Examples of protein synthesis antibiotics?

Tetracyclines, aminoglycosides

What do nucleic acid synthesis antibiotics do?

Prevent formation of DNA/RNA

What are nucleic acid synthesis affective against?

UTIs

Examples of nucleic acid synthesis antibiotics

Sulfonamides