Bacteria Flashcards

-DNA
-Biochemical Reactions- used for growth and energy conversions
-Response to Stimuli
-Reproduce to produce offspring
-Adapt from one generation to the next
-Interact w/ other organisms in environment

It maintains a stable internal environment.

They interact through a multicellular association.

Quorum sensing

Genetic organization with DNA in chromosomes, compartmentation with cell membranes, metabolic organization in the cytoplasm, protein synthesis at ribosomes

The cell is the fundamental unit of life.

Information is organized in chromosomes.

Cytoplasm is surrounded by a cell membrane which selectively allows substances in or out of the cell.

The chemical reactions that occur in the cell.

Occurs at the ribosome.

Eukaryotes have membrane-enclosed organelles. Some bacteria have micro compartments surrounded by protein.

Eukaryotes: Endoplasmic reticulum and Golgi apparatus
Prokaryotes: Cytoplasm

Eukaryotes: mitochondria perform cellular respiration in eukaryotes, while prokaryotes use the cytoplasm and cell membrane.
*ETS* is performed in the cell membrane (in proks) and everything else is in the cytoplasm.

Both eukaryotes and prokaryotes can perform photosynthesis.

The eukaryotic cytoskeleton gives the cell structure and transports materials within the cell. **What happens in the prokaryotic?**

Both eukaryotes and prokaryotes use flagella for motility, though the flagella differ structurally and functionally in the two groups.
Proks=Bacterial flagella
Euks=Eukaryotic flagella or cilia

Many prokaryotes and eukaryotes have a cell wall to help maintain water balance by osmosis.

Prokaryotic: Circular DNA chromosomes
Eukaryotic: Linear DNA chromosomes

Prok's and Euk's= cell membrane

Prok's and Euk's= Cytoplasm

Prok's and Euk's= Ribosomes

Prok's= Cytoplasm
Euk's=Endomembrane System

Prok's= Cell membrane
Euk's= Mitochondria and chloroplasts

Prok's= Thin protein filaments in cytoplasm
Euk's=Protein tubules and filaments in cytoplasm

Prok's and Euk's= cell wall

Taxonomy

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
Dr. King Philip Can Order Family Good Stuff

Nomenclature

Carolus Linnaeus

genus (capital); specific epithet (lower case); species (italics, or underlined)

Kingdoms and domains

Ernst H. Haeckel

Robert H. Whittaker: Plantae, Animalia, Protista, Fungi, Bacteria

Carl Woese; ribosomal RNA sequences.
Three domains include: bacteria, eukarya, and archaea

The three-domain system places the prokaryotes in separate lineages.

1-5 micrometers (um)

is used to observe most microorganisms.
-Visible light passes through multiple lenses and through the specimen.
-Light microscopes usually have at least 3 lenses: low power, high power, and oil-immersion
-The lens system must have high resolving power to see the specimen clearly.
*only under oil can you see bacteria clearly but you have to stain them as well.

It involves flooding a prepared specimen with basic dye to provide contrast.

Cells are stained with crystal violet and Gram's iodine solution and washed with a decolorizer.
-Safranin is applied as a counter stain.
-Gram-positive bacteria retain the crystal violet, whereas gram-negative bacteria do not (turn orange-red).

Mycobacteria can be stained with carbol-fuchsin in acid-fast technique. The cells turn red. Example: TB.

1. The type of cell: (only 2 types Prokaryotic and Eukaryotic cell)
2. Number of cells: (unicellular- kingdom protista- unicellular eukaryotes) and multicellular-everything else.
3. Type of nutrition: Autotrophic nutrition (photosynthesis=kingdom Plantae) everything else is a heterotroph (other feeders) these fall into two categories: ingestive (kingdom Animalia) and absorptive (kingdom Fungi)

used to confirm: Clostridium bacillus if it's present then it turns aqua/green color if it's absent then it turns pink (all vegetative cells).

Gram +, coccus, staphylococcus (grape like), yellow

Gram +, bacillus, streptobacillus

Gram +, bacillus, single, *forms endospores

Gram -, spirillum, single, red

Gram -, coccus, diplococcus

Gram +, coccus, streptococcus

Gram +, bacillus, palisade arrangement

Gram -, bacillus, single

Gram -, bacillus, single

Gram -, bacillus, single

Gram +, bacillus, (irregular rod, acid-fast, single)

Gram +, coccus, tetrad & sercanae

Gram -, bacillus, single

classified by how they sexually reproduce (produce spores)
1. Zygomycota-sexually reproduce using zygospores
2. Ascomycota- sexually reproduce using ascospores
3. Basidiomycota-sexually reproduce using basidiospores
4. Deuteromycote-mitosporic (no known spores)

classified by how they move (locomotions) to get their food
1. Mastigophorans-use flagella (whip like motions)
2. Sarcodinia-Pseudopods-false feet, ameba,
3. Ciliphorans- use cilia
4. Apicomplexans- Vectors, use an insect to move

classified by morphology
1. Nematoda-roundworms
2. Platyhelminth-flatworms
-Class cestoda-tape worms
-Class trematoda-flukes
3. Annelida- leeches and earth worms, segmented

Zygomycota-zygospores-Rhizopus nigrocans-not a pathogen, has fibers, black bread cotton white mold.

Basidiomycota-basidiospores-mushrooms-not a pathogen

Ascomycota-ascospores-Penicillium notatum (blue-green mold), Aspergillus niger (black mold *pathogen)

Candida albicans-mold in humans, yeast infection if too much

Saccharyces cervisine-brewer's yeast

1. Mastigophorans- Trypanosoma- African sleeping sickness, American tryponosomiasis
2. Ciliophorans- Balantidium coli- dysentery (excessive diarrhea)
3. Sarcodinia-Entamoeba histolytica- Amebic dysentery
4. Apicomplexa- Plasmodium vivax- Malaria

Bacteria

live in the mouth and some are STD's like Treponema pallidum that causes syphylis

Euryarchaeota contain:
-Methanogens-live in anoxic environments
-Extreme halophiles-salt-lovers
-Thermoacidophiles-grow at high temperatures with low pH

Morphology (shape) and arrangement

Bacillus: single, diplobacillus, streptobacillus

Coccus; single, diplococcus, streptococcus, staphylococcus

Vibrios (comma-shaped), spirilla (helical), or spirochete

-sensing/responding to the surrounding environment.
-compartmentation of metabolism
-growth and reproduction

Pili are protein fibers extending from the surface of many bacteria that are used for attachment.
-Adhesins attach cells to surfaces
-Form biofilms and microcolonies
Some bacterial species have conjugation pili, used to transfer genetic material between cells. (f-plasmid; sex pili)

Flagella; can be used for motility

When bacteria move up the concentration gradient of a chemical attractant.
-Some prokaryotes move without flagella by gliding across a solid surface.

endoflagella
example: Treponema pallidum (causes syphilis)

Glycocalyx- adhering layer of polysaccharides (and sometimes small proteins) - It protects the cells from the environment and allows them to attach to surfaces
Thin layer- Slime layer
Thick layer- Capsule - Extreme velent; can cause extreme illness (hard for wbc phagocytosis to occur; too slimy and thick) Causes disease like Klebsiella pneumoniae (#1 cause nosocomial hospital death for elderly; acquired pneumonia)

-counter rigidity, not flexible, tough and protective external shell
-maintains cell shape and water balance

Thick peptidoglycan cell walls containing teichoic acid. (amino acid and glucose derivatives) only polysaccharide back bone, NAG NAM-long rod of sugars, Amino acids are the chains attached to the polysaccharide.

*Fungi-chitin
*Plants & Algae- cellulose-complex

Have 2D peptidoglycan layer and no teichoic acid. Has an outer membrane, separated from the cell membrane by the periplasmic space.
-The outer membrane contains proteins called porins that selectively allow small molecules into the periplasmic space.
-Lipid A-Endotoxin?
-Much more difficult to deal with medically.

No archae have peptidoglycan in the cell wall, but some have pseudopeptidoglycan. Others have polysaccharides, proteins, or both.

-The s-layer is the most common archaeal cell wall, consisting of protein or glycoprotein in a crystal lattice.

Primary function of cell membrane is transport. **
-fluid thin layer of phospholipid and protein (the fluid mosaic model)
-The phospholipid molecules are arranged in a bilayer
-Hydrophobic fatty acid chains in the phospholipids form a permeability barrier.

Antimicrobial substances

cell wall synthesis
energy metabolism
dna replication
sensation of stimuli
molecule transport- passive (facilitated diffusion) active (active transport) using ATP

*Prokaryotes have a lot more function (than Euks) because they have no intercellular membrane.

-Hydrophobic lipid tails are attached to glycerol differently in Archaea.
-Fatty acids are usually absent
-Adjacent lipid tails are bound together forming a lipid monolayer, instead of a bilayer.
-None of them are medically important.

It represents a subcompartment containing the chromosomes.
-This is the region that gets stained.

The chromosome is usually a closed loop of DNA and protein.
The DNA contains the genes.

Genome

Haploid

Small circular molecules of DNA (smaller than the chromosome)
-Each plasmid is a closed loop, containing 5-10 genes
-extrachromosomal DNA

They can be transferred between cells and be used as vectors in genetic engineering.

Plasmids provide genetic flexibility, for example, R plasmids carry genes for resistance to antibiotics.

R plasmids-antibiotic resistance
F plasmids- fertility (conjugation pilli)

Mycoplasmas

Treponema pallidum- syphilis
Borrelia burgdarfeni- lyme disease
Borrelia recurimentas- relapsing fever

Protein synthesis, same function just different structure than Eukaryotic cells, not membrane bound in proks but are membrane bound in euks

Store nutrients or build blocks for cellular structures.

gas vesicles

Contain crystals of magnetite or greigite, allowing cells to respond to magnetic fields.

cell division and help determine cell shape.
-Prokaryotes contain a homolog of eukaryotic tubulin--it forms filaments similar to those found in microtubules

It is part of the cell cycle.
-Very quick cell division, shorter doubling time quicker incubation period.
-Acid fast micro bacterium grows very slowly symptoms appear 3,6,9 months.

Cell increases in mass and size

DNA replicates and the two strands separate

Synthesis of a septum forms two identical cells.

Asexually.

The interval of time between successive binary fission.

shorter, shorter

No cell division occurs while bacteria adapt to their new environment

When exponential growth of the population occurs, human disease symptoms usually develop.

When reproductive and death rates equalize

When the accumulation of waste products and scarcity of resources causes the population to die.

A response to potential or actual environmental change. Non dividing state.

Persister Cell Formation
Endospore Formation

They stop dividing but maintain a low rate of metabolism under stress.

Nutrient limitation *** important
-Endospores are a highly resistant structure formed by species of Bacillus and Clostridium when nutrient supplies are low.
-Endospores are resistant to desiccation and heat.

The protective layers break down and the spore germinates into a vegetative cell. (veg cells stain pink in endospore staining, but the spores will stain aqua/green)

Temperature, Oxygen, pH level, Hydrostatic and Osmotic Pressure

Grow optimally at 0-20*C and make up the largest portion of all prokaryotes on Earth.

Live at medium temp. range 20-40*C; includes pathogens in humans.

Live best around 40-80*C; in compost heaps and hot springs.

Are archaea that grow optimally above 80*C, found in seafloor hot-water vents

Many prokaryotes are obligate aerobes, which require oxygen to grow.

Live in low oxygen environments.

Used to test an organism's oxygen sensitivity.
-In lab we use it to grow Clostridium

Do not or cannot use oxygen; aerotolerant species are insensitive to oxygen, but obligate anaerobes are inhibited or killed by oxygen.
Ex- clostridium

Grow either with oxygen or in reduced oxygen environments.
Ex-E.coli

They require an atmosphere low in oxygen and rich in carbon dioxide.

Neutrophiles

Acid tolerant prokaryotes
Ex: those used to turn milk into buttermilk, sour cream, and yogurt

Can withstand incredibly high hydrostatic pressure
-Ex: Psychrophiles living at the bottom of the ocean.

Salt-tolerant prokaryotes
-They can maintain optimal osmotic pressure
-Ex: Vibrio cholera that causes cholera

Complex medium and Synthetic medium

A chemical unidentified medium or complex medium such as a nutrient broth (liquid media) or nutrient agar (solidifying agent for solid media).

The chemical composition of the medium is known.

It contains ingredients to inhibit growth of certain species and allow the growth of others.

1. Crystal Violet Agar-plates (absorbed well by Gram +) selective not differential, to select gram- bacteria

2. Eosin Methylene blue agar plates (totally inhibit Gram +) both selective and differential. Selects gram - bacteria. White and clear colonies all gram -. Metallic green colonies is also gram - but this confirms the presence of E.coli. EMB Agar used only to confirm presence of E. coli.

Contains specific chemicals to indicate species that possess or lack a biochemical process.
-distinguished groups
-based on colors

1. EMB agar- all the colors are gram -, on exam * EMB is an example of differential & selective media; used to confirm presence of E. coli.

2. Sheep's Blood Agar; selective & differential
-No hemolysis=gamma (V) hemolysis
-Partial hemolysis=alpha (looks like fish) hemolysis
-Complete hemolysis=beta (B) hemolysis

**LOOK AT PICTURE IN NOTEBOOK PG 25**

You have Streptococcus pyogens that causes strep throat.

Cooked sheeps blood. In our lab we use it to grow Neiserria. "Enriched medium" Enriched with iron.
-Some "fastidious" organisms require an enriched medium containing specific nutrients.

cannot

pure cultures.

A population consisting of only one species of prokaryote.

Allows separation of species through dilution of a sample. Is this the same as streak plate?** listen to recording @ 27min. *

It is used to spread out individual cells to form discrete colonies of species.

Turbidity, Microscopic count, Estimate-through most probable # test, and
Standard plate count procedure

Cloudiness of a sample can be measured with a spectrophotometer.

Using counting chamber, placed under light microscope.

Colonies grow on a plate containing a sample of diluted broth. The number of colonies indicates the original number of viable (living) cells in the broth.