microbiology

What is a morphologically complex and has a membrane-enclosed nucleus?

Eucaryotes

What let to the discovery of viruses as disease causing agents?

bacterial filter that removed bacteria and larger microbes (Charles Chamberland)

The five kingdom classification scheme is

the Monera or Procaryotae, Protista, Fungi, Animalia, and Plantae

What are ribozymes?

RNA molecules that form peptide bonds and perform cellular work and replication

The three domain scheme is

Bacteria, Archaea, and Eucarya

The three domain scheme is based on?

a comparaison of ribosomal RNA

The earliest cells may have been

RNA surrounded by liposomes

What are the three bacterial morphology?

-bacillus (little rod)
-coccus (grain or berry)
-spirillum (coiled or helical)

What are the types of light microscopes?

-bright-field microscope
-dark-field microscope
-phase-contrast microscope
-fluorescence microscopes

What is a measure of how greatly a substance slows the velocity of light?

Refractive index

The direction and magnitude of bending light in a microscope is determined by the _

refractive indexes of the two media forming the interface

Which microscope produces a dark image against a brighter background?

the bright-field microscope

What is the product of the magnifications of the ocular lens and the objective lens?

the total magnification

What is the total magnification of the bright field, dark field, and phase-contrast microscopes?

2000x

What is the total resolution of the bright field, dark field, and phase contrast microscopes?

0.2um

What is the purpose of the bright field microscope?

for live and preserved stained specimens

What is the purpose of the dark field microscope?

to observe living, unstained preparations

Which microscopes are good for observing living cells?

-The Differential Interference Contrast Microscope
-Phase-contrast microscope

Which microscope enhances the contrast between intracellular structures having slight differences in the refractive index?

phase-contrast microscope

Which microscope shows a bright image of the object resulting from the fluorescent light emitted by the specimen?

the fluorescence microscope

The fluorescence microscope exposes the specimen to what types of light?

uv, violet, or blue

The distance between the center of the lens and focal point?

focal length

The shorter the focal point, the the magnification

greater

The shorter the wavelength, the the resolution

greater

The distance between the front surface of lens and surface of cover glass on specimen

Working distance

As the working distance decrease, the field of view _

decrease

As the field of view decrease, the light gets ____

dimmer

What is the purpose of adding the immersion oil?

to obtain more light by providing the same refraction energy as glass

As the magnification increases, what happens to the focal length?

it decrease

What is the charge of a bacteria cell surface?

negative charge

What is the charge of basic dyes?

positive charge

What is the charge of acid dyes?

negative charge

A thin, uniform film of bacterial growth on a glass slide in order to proceed with further staining for microscopic examination

smear

The process by which organism is killed and firmly attached to microscope slide

fixation

Heat fixation vs. Chemical fixing (not the procedure)

-heat fixation preserves overall shape but not internal structures
-chemical fixing protects fine cellular structure and shape of larger, more delicate organisms

What information does differential staining provide?

divides microorganisms into groups based on their staining properties

What is the most widely used differential staining procedure?

gram staining

Negative staining

the bacteria is not stained; the background is stained

What is shadowing in electron microscopy?

coating specimen with a thin film of heavy metal

What is the total magnification of the Transmission Electron Microscope and the Scanning Electron Microscope?

1,000,000x

What is the total magnification of the Scanning Electron Microscope?

1,000,000x

Which microscope uses electrons reflected from the surface of a specimen to create an image?

scanning electron microscope

Which microscope produces a 3-dimensional image of specimen's surface features

scanning electron microscope

In which microscope do the electrons scatter when they pass through thin sections of a specimen?

Transmission Electron Microscope

Which microscope uses transmitted electrons to produce an image?

Transmission Electron Microscope

Spherical or ball-shaped

cocci

Rod-shaped or cylindrical

bacilli

corkscrew shaped

spiral

When two cocci bacteria or stuck together, it is called ____

diplococci

A chain of cocci

Streptococcus

Cocci in a grape-like cluster

Staphylococcus

Vibrios are

curved rods

Describe the spirilla morphology

rigid bodies, move by flagella

Spirochetes morphology

Flexible bodies, move by axial filaments

Organisms that are variable in shape are called

pleomorphic

About 70 percent of antibiotics come from what genus

Streptomyces

What is the purpose of the Prokaryotic Cell Membrane

-It separates the cell from its environment
-It serves as a selectively permeable barrier

Archaea membranes have what type of phospholipid layer?

monolayer

What do most bacteria cells lack?

sterols (they have hopanoid)

What is the most widely used model of membrane structure?

fluid mosaic model

What is the phospholipid of archaea?

L-glycerol

What is the phospholipid of bacteria?

D-glycerol

What is the purpose of the complex foldings of the plasma membrane in photosynthetic bacteria?

to increase the surface area available for photosynthesis

What type of plasma membrane do bacteria with high respiratory activity may have?

a membrane with intensive foldings

Macroelements

-C, O, H, N, S, P, K, Ca, Mg, and Fe
-required in large amounts

Microelements

-Mn, Zn, Co, Mo, Ni, and Cu
-required in trace amounts

Requirements for Carbon, Hydrogen, and Oxygen

-often satisfied together
-Autotrophs: use C as their sole carbon source
-Heterotrophs: Use CO2 as their C source

What elements are needed for synthesis of important molecules such as amino acids, nucleic acids

Nitrogen, Phosphorus, and Sulfur

What is the use for amino acids?

for protein synthesis

What are purines and pyrimidines used for?

nucleic acid synthesis

What is the function of vitamins?

they function as enzyme cofactors

Bacteria can only take in _ particles across a selectively permeable membrane?

dissolved

All microorganisms use what type of transport mechanisms?

facilitated diffusion and active transport

What type of transport do bacteria and archaea use?

group translocation

Which microorganism only use endocytosis?

Eukarya

Molecules moving from regions of higher concentration to one of lower concentration between the cell's interior and the exterior is called ____

passive diffusion

Which molecules can move by passive diffusion?

water, O2, and CO2

How does facilitated diffusion differ from passive diffusion?

facilitated diffusion uses carrier molecules to effectively transport glycerol, sugars, and amino acids

Similarities in passive and facilitated diffusion

-movement of molecules is not energy dependent
-direction of movement is from high concentration to low concentration
-size of concentration gradient impacts rate of uptake

What is an energy dependent transport process that uses ATP or proton motive force to move molecules against the gradient.

Active transport

Which active transport uses ATP?

primary

Which type of active transport uses PMF or other ion gradient?

secondary

Which transport uses a high energy metabolic pathway intermediate?

group translocation

What happens in group translocation?

molecules are modified as they are transported across the membrane

The substance between the membrane and the nucleic is called _

cytoplasmic matrix

What is the cytoplasmic matrix often packed with?

ribosomes and inclusion bodies

What organism lacks a true cytoskeleton?

mycoplasma bacteria e.g. atypical pneumonia

What are the eukaryotic cell cytoplasmic elements

microtubules, microfilaments, and intermediate filaments

What type of protein is microtubules made of?

tubulin

What type of protein is microfilaments made of?

actin

Function of MreB/Mbl

Helps determine cell shape, may be involved in chromosome segregation, localizes proteins

An inclusion body found in cyanobacteria and some other aquatic forms. Helps the organism float on the surface

Gas vacuoles

An inclusion bodies that contain iron in the form of magnetite

Magnetosomes

Types of organic inclusion bodies

Poly b-hydroxybutyrate,Glycogen, Lipid Droplets

Type of inorganic inclusion bodies

-Polyphosphate or volition granules (metachromatic granules)
-sulfar granules

Complex structures consisting of protein and RNA .They are responsible for the synthesis of cellular proteins

Ribosomes

Procaryotic ribosomes are in structure to, but than, eucaryotic ribosomes

similar; smaller

What type of ribosomes produce proteins for transport?

bound Ribosomes

What is the prokaryotic ribosome called?

70S

What is the eukaryotic ribosome called?

80S