Microbiology Exam 1

Microscopy that uses light

-bright field -dark field -phase contrast -epifluorescence -confocal

Eukarya

-can be single or multicellular -HAS nucleus -NO peptidoglycan -found in nonextreme environments -NOT prokaryotic in structure

Three most important energy-conserving cellular organelles

-chloroplasts -mitochondria -hydrogenosomes

Peptidoglycan

-contains D-amino acids not found in proteins -polymer of alternating N-acetylglucosamine (NAG) and N-acetykmuramic acid (NAM)

endospore

-core has high amounts of dipicolinic acid complexed with calcium ions -core has a slightly acidic pH -core has low water content

slime layer

-easily removed -diffuse (unorganized) -facilitate motility

algae

-eukaryotic -single cell or multicellular members -all members are photosynthetic -members have a cell wall

fungi

-eukaryotic -single cell or multicellular members -members are NOT photosynthetic -members have a cell wall

protozoa

-eukaryotic -unicellular members -SOME members are photosynthetic -members DO NOT have a cell wall

Plastids

-found in photosynthetic protists and plants -often contain pigments -can be a site of synthesis and storage of food reserves -chloroplasts are one type of plastid

functions of actin filaments

-moving structures within the cell -cytokinesis -endocytosis -amoeboid movement

gram negative

-pink -thin peptidoglycan -teichoic acids absent -outer membrane present -LPS present -less sensitive to penicillin -not sensitive to lysozyme

gram positive

-purple -thick peptidoglycan -teichoic acids present -outer membrane absent -more sensitive to penicillin -sensitive to lysozyme

microscopy that does not use light

-scanning electron -cryotomography -scanning tunneling​ -atomic force

Bacteria

-usually single-celled -NO nucleus -HAS peptidoglycan -found in all environments -prokaryotic in structure

Archea

-usually single-celled -NO nucleus -NO peptidoglycan -found in all environments -prokaryotic in structure

capsule

-well organized -not easily removed -helps resist phagocytosis

Koch's Postulates

1. The microorganism must be present in every case of the disease but absent from healthy organisms. 2. The suspected microorganisms must be isolated and grown in a pure culture. 3. The same disease must result when the isolated microorganism is inoculated into a healthy host. 4. The same microorganisms must be isolated again from the diseased host.

Defective proteins

1. Ubiquitin is attached to defective protein 2. The tagged protein is recognized by the proteasome 3. The defective protein is cleaved into smaller peptides 4. Ubiquitin is released and recyled

strain

A common definition is that bacterial and archaeal species are a collection

endospore

A dormant cell state

When observing flagella distribution patterns, bacteria with a single flagellum at each pole are called ________________ bacteria.

Amphitrichous

viroid

An infectious agent consisting of only RNA

prion

An infectious agent consisting of only protein

virus

An infectious agent made up of protein, nucleic acids and sometimes a lipid membrane

gas vesicle

Contains compounds that aid in buoyancy

chromosome

Contains genetic information required for survival

storage granules

Contains high-molecular weight polymers

plasmid

Extrachromosomal DNA molecules

Which of the following advances best describes that today we may be experiencing a second golden age of microbiology?

Genomic Testing

cytoskeleton

Involved in cell division and controlling cell shape

Examine the following genetic sequences and determine which pair are the most similar based on their ED (evolutionary distances). Species 1 = ATTGGCCATT Species 2 = ATTCCGGTTT Species 3 = TTTGGCCATT Species 4 = ATTCCCCCCC

Most similar are: Species 1 = ATTGGCCATT Species 3 = TTTGGCCATT

When analyzing the outer membrane of Gram-negative bacteria, which part of lipopolysaccharide induces an antibody response?

O antigen

To determine the relatedness of a new species of microbe to other species, genes that encode small subunit ____ molecules are compared to determine the number of differences in the sequence.

RNA

medical microbiology

The study of diseases in humans and animals is the field of _____________

in eukaryotic cells, the thinnest cytoskeletal filaments are composed of ______

actin

Merging both medical and microbial ecology, the field of ___________ microbiology concerns the role of microbes in crop production and as pesticides.

agricultural

biovars

biochemical or physiological differences

lipid rafts

contain lipids and proteins

proteasome

degrade misfiled proteins

Fredrick Griffith

describes bacterial transformation

John Snow

determined the source of the cholera outbreak

morphovars

differ morphologically

Louis Pasteur

disproves spontaneous generation with swan neck flasks

serovars

distinctive properties that can be detected by antibodies

Clostridium botulinum, which produces a toxin that causes botulism, is a major concern of the food industry due to its production of an extremely heat-resistant ________.

endospore

The three domain system, comprising the bacteria, the _________, and the archaea, was devised in the 1970s by Carl Woese.

eukarya

Which of the following microscopes typically uses dyes or antibodies?

fluorescence microscope

Another area that parallels agricultural microbiology is the study of microbial spoilage, which is part of the field of __________ microbiology.

food and dairy

Capsules and slime layers are networks of polysaccharides that can extend from the bacterial surface. Both capsules and slime layers can be encompassed by the general term _________________.

glycocalyx

Scientists study how the immune system protects the body in the field of

immunology

Researchers in the field of __________ microbiology develop ways to exploit the metabolic abilities of microbes to generate valuable products.

industrial

Atovaquone

inhibits the electron transport system in protozoans and thereby, limits the microbes abilities to have chemical reactions.

ribosome

involved in protein synthesis

The first direct evidence of primitive cellular life was the 1977 discovery of _________ fossils in the Swartkoppie chert, a type of granular sedimentary rock rich in silica.

microbial

In the field of _________, however, a variety of approaches are used to describe microbial diversity in terms of relationships between organisms and their environments.

microbial ecology

A(n) ________ microscope keeps an object in focus when the objective lens is changed.

parfocal

pathovars

pathogenic strains distinguished by the plants in which they cause disease

The bacteria flagellum is driven to rotate by protons moving down a charge and pH gradient and the energy provided is called the _________ ___________ ____________.

proton motive force

Epidemiologists working in the field of __________ microbiology monitor the prevalence of disease in populations.

public health

Carl Woese distinguished between the members of the Archaea and the Bacteria using studies of their

ribosomal RNA

What microscope would be the best to use to view cell surface features of a specimen?

scanning electron

Which microscope is the best for viewing the DNA double helix?

scanning tunneling

inside eukaryotic cells, the ________ pathway functions to move cellular material to various locations within the cell, as well as to the plasma membrane or cell exterior

secretory

A lens with a _____ focal length should have a greater magnification.

short

Many bacteria have overcome the difficulty of iron uptake by secreting low-molecular, weight iron-binding proteins called _________.

siderophores

When light generated by a lamp in a light microscope passes into a lens, the speed of the light _______ because the glass lens has a _______ refractive index than the air from which the light came.

slows; greater

Edward Jenner

smallpox vaccine

What would be the best technique to prepare and view the internal structures of fungal hyphae?

transmission electron

Which microscope would be the best to use to constituents within a cell?

transmission electron

penicillin

will bind to a microbial enzyme that synthesizes the bacterial cell wall.

Streptomycin

will bind to ribosomes and interfere with proper protein synthesis.

Acyclovir

will inhibit the process of viral genome replication.

Rifamycin

will prevent transcription machinery from producing mRNA.