Microbiology - 1 - (pg 17-43)

Is there treatments/vaccinations for BSE? How many cases in the US? Incidence rates: What other animal can have a prion disease?

NONE 2 low incidence Scrapie - sheep

Most bacterial infections are ____________. Successfully treating a bacterial infection will depend on what?

extracellular being able to ID and eliminate the causative factors at the cellular level

Which of the following reproduce by spores? a. fungus b. prion c. virus d. protozoan

a

DNA is composed of what four molecules:

adenine (A), guanine (G), cytosine (C), and thymine (T)

Examples of prokaryotes: Examples of eukaryotes:

all bacteria fungi, protozoa, plants, animals, and humans

How is the cell exterior different with animals and bacteria?

animals - have only elastic cell membranes as cell envelopes bacteria - have both semipermeable cell membranes and cell walls or outer membranes, which can expand as cells grow

What is chlorophyll? Where is fungus present? EX:

any of a group of green pigments involved in oxygen-producing photosynthesis in plants; air, soil, water - unicellular yeasts, multicellular molds, macroscopic species (mushrooms)

What is fission? What is conjugation? What is a gametocyte?

asexual reproduction; the cell divides into two or more daughter parts, each of which becomes an individual organism sexual transfer of genetic material between two unicellular organisms cell that produces reproductive cells

Some organisms, such as spirochetes, have unique structures called ____________. What are they? What do they do?

axial filaments bundles of filaments that arise at the ends of cells and spiral or wrap around their respective cell in a twisting fashion. produces movement (like a corkscrew)

Name the cell structure below not found in animal cells that gives the Gram positive bacteria cell its thick, rigid exterior and prevents its from rupturing when pressure inside exceeds the outside. a. flagella b. ribosome c. cell wall d. plasmid

c

Why are ribosomes considered so important? a. contain DNA, the genetic material controlling cellular growth, replication, and damage repair. b. described as the "body" of the cell, ribosomes surround the nucleoid or nucleus c. they are the site of protein synthesis d. they are mobile pieces of genetic material

c

A _____________ or " ________ __________" surrounds many types of bacteria. Describe this layer: What does it do?

capsule or "slime layer" thick, sticky, gelantinous film is synthesized by enzymes located on the bacterial cell membrane surface. protects the bacteria and increases virulence; protects from antimicrobials

Describe active processes:

chemical E from a specialized molecule called ATP is required to move molecules from one side to the other and from outside to inside. Utilizes carrier molecules

What is a symbiotic relationship. Example:

coexist harmoniously with host animals and both benefit bacteria/protozoa in rumen

Some bacteria are covered by a capsule made up of a sticky, gelantinous material. What role does it play? a. none; it is an extra component b. it is critical for reproduction c. it makes the bacteria move vulnerable to the action of most antimicrobials d. it protects the bacteria against the hosts white blood cells

d

How do antimicrobials kill bacteria? penicillin type: fluoroquinolones:

destroying or inhibiting various bacterial cell structures break down walls/membranes destroy bacterial DNA

All living cells fall into one of two categories: What is a true nucleus? Which contains a true nucleus? What about complexity?

eukaryotes - true nucleus prokaryotes - no true nucleus contains DNA as well as other microscopic structures that are important a prokaryotes has no true nucleus or membrane and is considered less complex.

A protozoan is a __________ organism that: 1. 2. 3.

eukaryotic 1. is unicellular 2. is usually free-living, but sometimes leads to parasitic existence 3. reproduces asexually by fission, budding or multiple fission, or sexually by conjugation or gametocyte production

A fungus is a ___________ organism. Three characteristics:

eukaryotic; 1. has no chlorophyll, 2. has a rigid wall during some stages of its life cycle, 3. reproduces by spore formation

What is simple diffusion? Movement across a cell membrane is called what?

requires no Energy; movement from high concentration to low osmosisi - constantly trying to get equilibrium

What is cytoplasm? What does it contain? Components of cytoplasm?

semifluid material inside cell membrane ribosomes, storage granules, and other structures 80% Water, protein, CHOS, fats, minerals, sales. All biochemical processes occur in the cytoplasm

Definition of eukaryotes: Definition of prokaryotes:

single-celled or multi-cellular organisms whose cells contain a distinct membrane bound nucleus. organisms characterized by the abscence of a nuclear membrane and by DNA that is not organized into chromosomes free in cytoplasm.

What molecules move easily across the cell membranes? What about large molecules or molecules carrying an electric charge?

smaller molecules - oxygen, carbon dioxide, some simple sugars, and fat soluble molecules (because membrane is fat soluble) move by carrier molecules

A virus is an organism that: 1. 2. 3.

1. has a core of genetic material 2. wraps a protein coat around its genetic material 3. cannot replicate itself without being inside a host cell

Which of the following is true about eukaryotic organisms? a. Eukaryotes lack true nuclei and nuclear membranes b. fungi, protozoa, plants and bacteria are eukaryotes c. animals and humans are eukaryotes d. DNA of eukaryotes organisms is found outside the nucleus

C

Example of a virus infection being related to a bacterial infection:

Viral infection of IBR, PI3, or BRSV leads to disabled protective cells lining the airways, allowing other microbes such as Pasturella or Mannheimia which are uuslaly kept in check by immune cells to proliferate and cause disease.

Comparison of viruses and bacteria: Comparative size? Exterior structure? Genetic material? Sensitive to antibacterials? location within host?

Viruses - 1/10 size of bacteria, Bacteria - 10x size of virus Virus - protein shell, Bacteria - cell wall/membrane Virus - DNA or RNA, but not both, Bacteria - DNA, RNA present for translating/transcribing DNA information into proteins. Virus - NO, Bacteria - YES Virus - inside cell, Bacteria - inside cell or in the small space surrounding individual cells (extracellular) depending on type of bacteria.

What about disease with a protozoa?

only a few associated with disease but they are the most important and devastating.. malaria African sleeping sickness coccidiosis

What about diseases involving fungus?

only a few species actually cause disease, they are rarely fatal, problematic since they develop slowly, are difficult to diagnose, and resist treatment

In a Gram positive bacterium, where does the cell wall lie? What about Gram negative?

outside the cell membrane - the cell wall consists of many laters of peptidoglycan, which forms a thick, rigid layer. Thicker means it is more resistant to breakage. has an outer membrance that covers the exterior of the cell rather than a thick cell wall. A thin layer of peptidoglycan is sandwiched between the two membranes

What two processes do substances move across cells?

passive active

Regarding what prions do, the altered protein _______ to form minute fibers or filaments within neurons causing ___________. Most important example:

polymerizes spongiform encephalopathy BSE - Bovine Spongiform Encephalopathy "Mad Cow Disease"

Bacteria are a ______________ organism that: 1. 2. 3.

prokaryotic 1. contain DNA floating freely in cytoplasm 2. are surrounded by a cell wall and/or outer membrance 3. can replicate without host cells by binary fission, generally with rapid population growth, a condition favorable to the development of mutant strains resulting from random changes in the genetic code.

What is the most important function of a cell membrane? It is made up of a double layer of ___________. Protein molecules embedded in these layers act as channels or ________________.

to be semipermeable barrier through which selected molecules enter and exit. phospholipids carrier proteins.

What does it mean to polymerize? What is spongiform encephalopathy?

undergo bonding to form a polymer, a high-molecular-weight compound made of numerous repeatedly linked units. A class of prion diseases including scrapie, BSE, and Creutzfeldt-Jakob disease that produces a "spongy" microscopic appearance of the brain.

What is the nucleoid? DNA molecules are arranged how? What does this look like in bacteria?

"control center" - contains DNA chromosomes single, ring shaped chromosome

Make sure you can ID the parts of a bacteria cell

...

Which of the following statements is true about viruses? a. can replicate outside the host cell b. contain both RNA and DNA c. keep bacterial from invading host cells d. contain either DNA or RNA, but never both

D

How are bacteria named? What is capitalized? What does "spp" stand for?

Genus + species Genus indicates all species of that genus are included.

What type of bacteria have pili or fimbriae? What role do they play?

Gram negative allow bacterium to attach to a site to replicate and cause infection; little hairs that are much shorter than flagella

BSE first appeared in cows in _______ in December ________ and reached a yearly peak of ________ confirmed cases in ___________. What was it linked to?

Great Britain 1986 37,280 1992 feeding recycled carcasses f BSE infected cattle

The flagellar protein called _______________ is an important marker used to distinguish between two _________ within a species of Gram negative bacteria.

H antigen serovars (subsets of a bacterial species)

What are ribosomes? How do ribosomes differ?

found in prokaryotic and eukaryotic "protein factories" Bacterial ribosomes are smaller than those found in eukaryotic cells and differ in their sensitivity to certain antimicrobials.

What are endospores?

highly durable, dehydrated structures with extra thick walls. certain Gram positive bacteria contain them within their cell walls; they can withstand heat, limited water, and chemical exposure. Bacteria can survive for years.

What is an opportunistic relationship? When does this happen?

if circumstances change, turns a commensal bacteria to an opportunistic - releasing chemicals/toxins that harm when defense system is compromised

What is a commensal relationship?

live within host without causing harm, but provide no benefit. may benefit if organism limits growth of pathogenic microbes - flora - fauna

What are Flagella? Why are they useful?

long filamentous fibers attached to one end of a bacterium that propel it by waving back and forth bacteria with flagella can move towards the good and away from the bad

What is a prion? What are 3 things scientists believe that they do?

microscopic protein particle 1. are capable of infecting cells and causing self-replication (similar to a virus) even though prions contain no nucleic acid. 2. induce transportation of the gene that codes for prion protein. 3. alter the folding of the expressed prion protein

What is a facilitated diffusion?

no Energy required but a carrier protein is involved; undergo shape changes to enable them to transport substances - moving from high concentration to low

The center of a bacterium cell = ____________ The center of a eukaryotic cell = ____________

nuceloid nucleus

Viruses are the ____________ and _________ of the microbes. What is the genetic material? What do they rely on? They are borderline what?

smallest, least complex RNA/DNA - but not both host cell - multiply/produce viral components living/nonliving - argument

Which are closer related, genus or species?

species. genus is the common ancestor

Define nucleus:

spherical, membrane bound body within a linving cell that contains the chromosomes and one or more nucleoli

How do you ID a Gram positive or negative bacteria? What is a peptidoglycan?

structural cell wall difference compound of peptides and sugars found in bacterial cell envelopes. Responsible for structural rigidity of cells.

What do ribosomes contain?

the RNA molecules that allow protein assembly