Microbiology Lecture Notes 1&2 – Flashcards

Bacteria are all unicellular

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All bacteria are prokarotic

This means they have no membrane bound nuclues

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Prokaryotic (prenucleus) and Eukaryotic (well-defined nuclues)

Bacteria are prokarotic

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The organism is a bacteria 

(This is mostly true, it could also be an archae.)

Eukaryotic, with one exception. 

• Archaea are also prokaryotic 
• Every other microorganism (fungi, protozoa, algae) is eurkaryotic, as are we, plants and animals. 
• Viruses are neither prokaryotic or eukaryotic

Deoxyribonucleic acid (DNA) is a molecule that encodes the genetic instructions used in the development and functioning of all known living organisms and many viruses.

YES!

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Ribosomes assemble proteins.

The ribosome (from ribonucleic acid and the Greek soma, meaning "body") is a large and complex molecular machine, found within all living cells, that serves as the primary site of biological protein synthesis (translation). Ribosomes link amino acids together in the order specified by messenger RNA (mRNA) molecules. 

NONE! Ribosomes are the only organelles present in prokaryotic cells. 

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No. The only organelles present in bacteria are ribosomes.

(Side note: They make their energy in their plasma or cell membrane instead of in mitochondria)

• Eukaryotic cells will have: 
• centrioles
• mitochondria
• microtubules
• endoplasmic reticulum 
• Prokaryotic cells & Eukaryotic cells will have
• ribosomes

• Which of the following do prokayotic and eurkaryotic cells have in common?
• a. Cholesterol in the cell membrane ( only Eukarotes)
• b. Cytoplasm
• c. Nucleus ( only Eurkaryotes)
• d. Endoplasmic reticulum (only Eukaryotes)

1. Phospholipid bilayer

2. Protein Channels

3. Cholesterol

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The amount of cholesterol in its cell membrane. 

Relatively greater amounts of cholesterol stabilize the cell membrane of the cuboidal cell, giving it more structure and an easily identifiable square shape. 

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Bacterial cells always have a cell wall. 

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No. Some eukaryotic cells (e.g. plant, fungi, some insect cells) have a cell wall. Some do not (mammalian cells).

peptidoglycan, a charbohydrate-protein complex

An antibiotic is any substance produced by a microorganism that is antagonistic to the growth of other microorganisms in high dilution.

• This definition excludes substances that kill bacteria but are not produced by microorganisms (such as gastric juices and hydrogen peroxide). 
• It also excludes synthetic antibacterial compounds such as the sulfonamides or drugs. 

Penicillin is an antibiotic because it is produced by a living mold.

Amoxicillin is a drug, a synthetic.

All antimicrobial agents target a structure or a process.

They do not target a specific organism. 

• A drug that is selectively toxic will do more damage to the organism  than to the host.

• Complete the following sentences to make them correct:
• When a drug has high selective toxicity, it does maximal damage to the organism and minimal damage to the host. 
• When a drug has low selective toxcity, it does almost as much damage to the host as it does to the organism. 

HIGH SELECTIVE TOXICITY

• this would indicate that the antimicrobial kills the micro with very little harm to the host. 

• DNA has
• a. low selective toxcity
• b. high selective toxcity
• c. no selective toxicity
• this is because all organisms have DNA. If a drug or antimicrobial targeted DNA, it would non-selectively target all organisms. 

• A cell membrane destabilzer used to treat a bacterial infection would
• a. have low selective toxcity
• b. have high selective toxcity
• c.  be an innappropriate choice
• because the cell membrane stabilizer, cholesterol, is not present in bacterial cells

changeable; a form or version of something that differs in some respect from other forms of the same thing or from a standard.

• e.g A variant structure in prokaroytic cells in a flagella. It is varient because not all prokaryotic cells have it.  

 constant, unchanging; always-always

An invariant structure in bacteria is cell walls. An invariant structure in gram negative cells is lipid A.

1. DNA
2. Ribosomes
3. Cell membrane 
4. Cytoplasm

Prokaryotic cells have no nucleus

Eukaryotic cells have a defined nucleus

Algae

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Malaria is a protozoa

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Fungi

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viruses

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Viruses are the kings of reinviting themselves. 

• Once inside the cell, the virus can hijack the cell's own replication machinery, which starts to make many copies of the virus. These viruses burst out of the cell, destroying it, and will attempt to infect many more cells unless tackled by the immune system. 

• Probiotics are bacteria that are supposed to be in your body anyway. Taking probiotics promotes normal flora.
• Organisims that produce disease, are generally transient organisms.
• Normal flora make it more difficult for transient organisms to set up in the body. 

1. Get into proper location. Find niche

2. Multiply

3. Compete with resident flora for nutrients

 Also, it must avoid waste products. 

Protozoa. 

• Many protozoan species are symbionts, some are parasites, and some are predators of soil bacteria and algae. There are an estimated 30,000 protozoan species.

Protozoa are eukaryotic unicellular organisms

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• Parasitic
• Mutualisic
• Commensal
• Saprophytic

Protozoa are associated with Algae

(They share a kingdom, PROTISTA)

There are genetic relationships between Protozoa and Algae

This has to do with mitochondrial DNA 

• Protozoa include both unicellular free living organisms, and unicellular parasitic organisms. 

YES! Many bacteria that live on humans are parasitic, for example, streptococcus pyogenes, the bacteria which causes strep throat. 

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• A parasitic organism
• Parasitism is a non-mutual symbiotic relationship between species, where one species, the parasite, benefits at the expense of the other, the host.

• mutualistic relationship
• A mutualistic relationship is when two organisms of different species "work together," each benefiting from the relationship. 

• The intestinal bacterial flora benefits its human host by keeping other organisims at bay, by producing vitamin K and B vitamins (esp K)
• The benefits to the organism, the bacterial flora include a place to stay with plenty of food. 
• This type of relationship is called a mutualistic relationship, because it is mutually beneficial. 

Commensalistic

(commensal is a latin word for sharing, in this case the host shares its body without being given anything in return)

A Saprophytic relationships is characterized by an organisim obtaining its nutrients by dissovling them, often from dead or decaying organic matter. 

• A saprophyte is an organism that obtains its nutrtion from assimilating large molecules of organic matter, rather than making its own food or obtaining it from a host. 

Parasitic and Saprophytic Relationships 

• NOTE: Parastic relationships harm the host but benefit the organism
• In a saprophytic relationship the organism does not depend on a host and utilizes organic matter to "do his own grocery shopping."
• Some saprophytes are parastic, meaning that they do harm.

PROTOZOA ARE UNICELULAR

Malaria.

LIGHT!

Algae are photosynthetic organisms. They produce food in response to light. 

Algae can cause human disease through toxins they produce

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• In addition to being saprophytic, some yeasts are also parasitic.

Viruses can not "grow" or reproduce unless they are in a living cell. 

Because the agar does not contain living cells, it will not grow there. 

Scientific Classification

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• Monera (including Archaea and Bacteria)
• Protistia (including Protozoa and Algae)
• Fungi (including Fungi)
• Plantae
• Aminalia

• Escherichia coli or E. coli
• Genus: Escherichia (named after German discover)
• Species: coli (because it lives in the colon)

• Plasmodium vivax
• P. vivax is a protozoal parasite which causes malaria.  

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Omphalotus nidiformis, or ghost fungus is a mushroom notable for its bioluminescent properties.

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• Most People Find Plants Attractive
• Monera Protista Fungi Plantae Animalia

• Lavandula angustifolia
• L. angustifolia is English lavender 

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Canis lupus 

C. lupus is a grey wolf

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MONERA

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Monera

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A salty enviroment like the dead sea.  

Halophile means salt loving. 

Protista

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Protozoal Protista: Giardia trophozoite

Algae Protistia: Saccharina japonica (kombu)

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Protista, Fungi, Plantae, Animaliae

MPFPA

• MPFPA
• Monera: Esterichia coli
• Protista: 
• Algae: Saccharina japonica 
• Protozoa: Plasmondium vivax
• Fungi: Omphalotus nidiformis
• Plantae: Lavandula angustifolia
• Animalea: Canis lupus

No. Staplococcus only tells us the genus, not the species that indentifies the specific organism.

• Staphylococcus is a genus of Gram-positive bacteria. Under the microscope, they appear round, and form in grape-like clusters. The Staphylococcus genus includes at least 40 species. Of these, nine have two subspecies and one has three subspecies.

• Yes, we know the genus and species, though in addition to this there are individual strains that differentiate members of the species. See below. 
• Staphylococcus aureus is a bacterium that is a member of the Firmicutes, and is frequently found in the human respiratory tract and on the skin. 
• Although S. aureus is not always pathogenic, it is a common cause of skin infections (e.g. boils), respiratory disease (e.g. sinusitis), and food poisoning. 
• Disease-associated strains often promote infections by producing potent protein toxins, and expressing cell-surface proteins that bind and inactivate antibodies. The emergence of antibiotic-resistant forms of pathogenic S. aureus (e.g. MRSA) is a worldwide problem in clinical medicine.

• There is both a genus and a species.
• The genus is capitalized.
• The species is not capitalized.
• Both are either underlined or italicized. 

e.g. Staphlococcus aureus

Eukaryotic cells are significantly bigger than bacteria. 

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Spontaneous Generation.

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• Anton Von Leeuwenhoek discovered that there were living, moving microorganisims in such things as sewer water and rain drops
• That these microorganisms were of a limited variety of shapes and arrangements
• He handcrafted one or perhaps more than one microscope.
• He called what would become microorganisms, "animialcules".

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Nope. He was a dry goods store owner and a Dutchman.

This is one of his drawings of a 100 year old ash tree.

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Leewenhoek noticed that came in a limited variety of shapes. 

Coccus- round or off round

Bacillius- rod shaped

etc 

Coccobacillus

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These are spirillum.

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These are spirochetes

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Coccobacillus

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Spirillum

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A vibrio

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Vibrio

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A spirochete

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Prof. McCleary noted that we would not be able to distinguish sprirochetes from spirillum unless they were motile. 

Spirochetes cause both. 

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Pleomorphic shapes

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• Changes in pH in an aging culture due to depletion of buffer system
• Changes in temperature ( too cool, too warm)
• Nutrient depletion in an aging culture

• In an old media bacteria may exhaust the capacity of the buffer, leading to acidosis in the organism and resultant pleomorphism. In addition, the nutrient source is depleted which can result in pleomorphism. 

• Organisms in pairs may indicate a diplo organism or an organism that is still in the divisional process. 
• The determining factor here is time.
•  If the organism was set on the previous nighy, it may still be in the division process. Come back and look at them later if that's the case. 

A diplo arrangment

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Streptococcus

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Streptococcus pyogenes

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Nope. They're generally curved, like a pearl necklack that has been dropped on a counter.

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Tetrads

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Staphlo arrangments

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8!

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Sercinae

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pick-up-sticks.

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Streptobacillus.

Note: Bacillus arrangments are always short end to short end.

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An artifact.

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