Micro final

What is the importance of the acid-fast bacteria?

Acid-fast bacteria contain mycolic acid, so they have an atypical cell wall. These organisms are very pathogenic and have a high degree of resistance to certain chemicals and dyes. These bacteria are identified by an acid-fast stain. Some of them have no cell wall and the membrane is strengthened by the use of sterols. These are often pleomorphic cells because of the lack of cell wall.

What is an endospore and why are they important?

An endospore is a unique type of dormant cell with in another cell. They are very resistant to heat, desiccation, chemicals, ultraviolet light, and boiling water. They remain dormant for a long time but can often become vegetative later on

Who are the main scientists involved in bacteriology?

Antony van Leeuwenhoek made the first simple microscope, and Robert Hooke coined the term cell.

What are the major branches or sub-fields of microbiology?

Bacteriology is the study of bacteria, mycology is the study of fungi, protozoology or parasitology is the study of protozoa, phycology is the study of algae, and virology is the study of viruses.

What are biofilms and why are they important?

Biofilms are caused by bacteria with capsules or slime layers adhering to surfaces and then producing products such as polysaccharides so that they stick to the surface and can grow. These can be very harmful to health as they can grow and grow and become very thick, making it near impossible to get rid of. Biofilms include things such as plaque. These biofilms can quorum sense, meaning they can communicate with each other about their environment or changes in it and then adapt to this change, making them even harder to get rid of

Why is strain identification important to medicine?

By identifying different strains you can determine causes or sources of food-borne illnesses, you can diagnose certain diseases, and you can perform forensic investigations of bioterrorism and biocrimes, and then you can go about finding a specific cure or fix for the problem.

What are the three domains of life and who devised this classification?

Carl Woese and George Fox are responsible for molecular taxonomy, or the idea that there are three different domains of life. These three domains are Eukarya, Bacteria, and Archaea.

Who are the main scientists involved in classification/taxonomy?

Carolus Linnaeus is responsible for classical taxonomy, which is the process of actually naming and grouping the organism (classification, nomenclature, identification)

What about algae makes them important in the environment and clinically?

Clinically algae are important because, although they do not directly cause disease, they can indirectly cause disease via toxins. They are important in the environment because they form the basis of the food chain.

What is dimorphism and what is its significance?

Dimorphic fungi have the ability to grow as either single yeast cells or multicellular mycelia. This makes the difference between a fungi being a mold or a yeast

Be able to label a typical prokaryotic cell

Draw this on the "cheat sheet" for the test

What are the main structural differences between prokaryotes and eukaryotes?

Eukaryotes are typically much bigger than prokaryotic cells, and prokaryotes do not have membrane bound nuclei. Eukaryotes have membrane bound nuclei and organelles.

Why are fungi important both medically and non-medically?

Fungi can be used to make antimicrobials, they can be used in studying eukaryotic cells, they produce important molecules such as insulin and hep. B vaccines, they produce beer, wine, and cheese. They also act as the biggest spoilers of food, cause crop diseases, allergic reactions, mycosis, and produce mycotoxins.

Be able to distinguish the differences between gram-negative and gram-positive cell walls.

Gram-positives have a thick layer of peptidoglycan and gram negatives have a thin layer of peptidoglycan and an outer membrane. This will be drawn on the "cheat sheet"

Who are the main scientists involved in asepsis and disinfection?

Ignaz Semmelweiss introduced hand washing into medicine, and Joseph Lister introduced the use of antiseptic agents and sterilization of instruments into medicine.

What are pathogens? Are all or most microbes pathogens?

Pathogens are organisms that are capable of growing within the body and doing harm. Many microbes that are on the skin, or part of your environment are normal flora, which are just microorganisms that live and exist with you

What is peptidoglycan and why is it important to bacteria? Why is it important to medicine?

Peptidoglycan is a sugar and is the main component of bacterial cell walls. It is important to bacteria because it helps the cell wall hold its shape and protects the cell from osmotic change. It is important to medicine because it makes a good antimicrobial drug target, because it is unique to bacteria.

What are the differences between prokaryotic and eukaryotic ribosomes and why is this important?

Prokaryotic ribosomes are 70S (made up or a small unit that is 30S and a large subunit that is 50S) and Eukaryotic ribosomes are 80S (made up of a small sub-unit that is 40S and a large sub-unit that is 60S). This is important medically because antibiotics can be made to target 70S ribosomes and won't attack, harm, or affect 80S ribosomes.

How are the protista classified?

Protista is a kingdom in the domain Eukarya. These are all eukaryotic organisms that are not fungi. This kingdom is divided into sub-kingdoms. These sub-kingdoms are algae and protozoa.

Who are the main scientists involved in cell theory?

Schleiden, Schwann, and Virchow

What are some criteria used for viral classification?

The Baltimore classification System classifies into 7 different classes based off of how the virus converts the genome into mRNA. They can also be classified by structure, chemical composition, genetic makeup, family ends in viridae and genus ends in virus

What functions are bacterial cell membranes responsible for?

The cell membrane or cell envelope helps maintain cell integrity and provides a dynamic barrier between the inside and outside of the cells

What are the two basic shapes for a virus?

The first basic shape of a virus is icosahedral, which is cubic, like dice, and the second is helical, which has a spiral shape. The third shape is complex, and complex viruses are typically bateriophages.

Who are the main scientists involved in germ theory of disease?

The main contributors to this were Louis Pasteur and Robert Koch (Koch's postulates)

What are the most common shapes and arrangements of bacterial cells?

The most common shapes of bacteria are cocci and rods, or bacilli. Cocci are little spheres and can be arranged in singles/randoms, diplococci, and streptococci. Bacilli are rod shaped and can be arranged in singles/randoms, diplobacilli, streptobacilli, or palisades. All of these will be drawn on the "cheat sheet"

How are fungi classified?

The study of fungi, or mycology, is broken into three divisions, unicellular yeast, mold, and mushrooms

How can viruses be grown in the lab?

There are three different methods used in growing viruses in the lab. The first is live animal innoculation, when microbiologists seclude a specific virus and grow it in a live animal. The second way is through bird embryos. During incubation of the egg, the viral is injected into it and the virus grows in the egg. The third way is cell/tissue culture. With this kind of growth, cells that support viral replication are grown in sheets , and the clear areas are where the virus has grown and killed the other cells.

Recognize bacterial appendages and their functions

There are two major groups of appendages, motility and attachment or channel. Flagella and axial filaments are involved in motility. Microorganisms with flagella swim because the flagella spin line propellers to move the cell. Axial filaments are internal flagella that are between the outer sheath and the cell wall. These perform "flexing motility" and move better in/on thicker substances. The attachment appendages include fimbrae and pili. These are both just used to attach microorganisms to different things. Fimbrae are much smaller, and pili can be used to transfer DNA.

What are slime layers and what do they contribute to microbial cells?

These are diffuse, irregular, and loosely attached gel-like layer outside of the cell wall that protects the cell and helps in or allows attachment to things. Once cells are attached, they can begin to form bioflims

What are viral spikes/peplomers used for?

These are structures on the envelope of the enveloped viruses, and they are tiny little arm-like proteins that project off the sides of the envelope and are needed for attachment to host cells.

What is the minimum structure of a virus?

To be a virus, all that is needed is a capsid (the protein coat that covers the virus) and DNA or RNA that contains the genetic code. Some viruses may contain envelopes, and/or matrix proteins, but these are not needed to make something a virus.

What is the difference between a trophozite and a cyst?

Trophozites are the feeding, vegetative forms and cysts are the dormant forms (of protozoa)

Why can't viruses be seen under the light microscope?

Viruses are sub-microscopic, so they are too small to be seen under normal light microscopes. Light microscopes can only see to approximately .2um

Why are some viruses naked and some enveloped? What are advantages and disadvantages of each of these?

When some viruses are leaving cells, they undergo exocytosis and take a portion of the cell's membrane as they leave. These are the enveloped cells, and the ones that leave without taking the membrane are naked. Enveloped viruses have an easier time getting into cells, but they cannot survive for a long time outside of the cell. Naked viruses have a harder time getting into cells, but can survive for longer outside of the cells and outside of the body.

Distinguish between yeast and mold

Yeast is a unicellular fungi and mold is a filamentous fungi