unit 1 lecture notes

microbiology - dr. patton - unit 1 lecture notes & textbook questions

what are oil immersion lenses used for?

they are used to improve microscope resolution. without the immersion oil, light scatters through the air

do shorter or longer wavelengths equate to better resolution?

shorter

who was the first to describe cells?

robert hooke

what specimen was robert hooke looking at when he first identified cells?

dead cork

robert hooke’s discovery of cells lead to ____ theory.

cell

how is a biofilm formed?

when free-floating bacteria adhere to a surface, produce slime, & form a colony

are biofilms difficult to observe?

yes

what type of microscope allows a clearer 3D structural image for biofilms?

confocal

what are the 4 components that all cells have?

cytoplasm, cell membrane, ribosomes, chromosomes

how is light used in differential interference contrast (DIC) microscopes?

2 beams of light with different polarizations are passed through the object to increase contrast

do differential interference contrast (DIC) microscopes give 2D or 3D images?

3D

do differential interference contrast (DIC) microscopes look at structures within living or dead, unstained organisms?

living

what are the 2 types of ribosomes found in eukaryotic cells? describe each.

free ribosomes float through the cytoplasm. fixed ribosomes are attached to the rough ER

imagine an image of staphylococcus clusters. what does it mean if all of the cells in the image are purple after a gram stain?

all of the cells in the image are gram-positive

does a simple microscope have a single lens or multiple lenses?

single

does a compound microscope have a single or multiple lenses?

multiple

what 2 things is the extracellular matrix composed of?

proteins & carbohydrates

what are the 2 main purposes of the extracellular matrix?

to protect the cell & transmit signals

when does a cell have an extracellular matrix? what’s the rule here?

all cells with an ECM don’t have a cell membrane, but not all cells without a cell membrane have an ECM

where is the extracellular matrix found"?

it sticks out into spaces between cells

what shape are eukaryotic chromosomes?

linear

how many chromosomes do eukaryotic cells have? : one or multiple

multiple

do bacteria or eukaryotic cells have a cytoskeleton?

eukaryotic cells

what do bacteria use instead of a cytoskeleton to maintain their shape?

filaments

eukaryotic cells vary greatly in structure & function :)

\:)

a petri dish is made of transparent plastic/glass, which allows transmission of a high proportion of ____. this transparency allows us to see through the dish to view the contents.

light

a slice of iron is ____ (has opacity). light isn’t transmitted through the material, making it impossible to see through it.

opaque

what is interference?

2 phases of light interact to produce patterns of interference like light or dark spots

what is an example of diffraction?

sunshine spreading past the clouds

what is diffraction?

bending of light

a timeline shows how the shape of the tree of life has changed over the centuries.

\
* linnaeus had 2 branches. what are they?
* ernst haeckel proposed 4 kingdoms. what are they?
* robert whittaker proposed adding a 5th kingdom. what are the 5 kingdoms now? (also added the domains of eukaryotes & prokaryotes).

animals, plants. animals, plants, protists, monera. animals, plants, protists, monera, fungi

what are protists?

unicellular eukaryotes

what are monera?

unicellular prokaryotes

how permeable is the prokaryotic plasma membrane?

selective permeability

is the fluid mosaic model a feature of the prokaryotic plasma membrane?

yes

what are glycoproteins?

transmembrane & peripheral proteins with carbohydrates attached

what are glycolipids?

carbohydrates attached to a lipid

archaeal membranes use ____ linkages & branched chains.

ether

bacterial membranes use ____ linkages.

ester

what are the 2 main points of cell theory?

cells are the foundation of life & cells only come from other cells

does higher energy equal higher or lower frequency?

lower

the TEM image in a biofilm shows well-defined internal structures of the cells because of varying _____ levels in the specimen.

opacity

STMs & AFMs allow us to view images at the ____ level.

atomic

STMs & AFMs allow us to view images at the atomic level. what does STM stand for?

scanning probe microscope

STMs & AFMs allow us to view images at the atomic level. what does AFM stand for?

atomic force microscope

does STM or AFM have better magnification?

STM

was STM or AFM used to see a pure gold surface with rows of atoms?

STM

does AFM or STM use constant voltage?

AFM

what do STMs & AFMs use to pass over specimens?

sharp probes

are bacterial/prokaryotic ribosomes & eukaryotic ribosomes the same?

no

in which type of microscopes are wavelengths used to excite fluorochromes?

fluorescence

fluorescence microscopes are used in clinical microbiology :)

\:)

in fluorescence microscopes, secondary _____ bind well to create a better image

antibodies

what are the 6 phases of mitosis?

prophase, prometaphase, metaphase, anaphase, telophase, cytokinesis

what is the form of the disks in the golgi apparatus?

stacks

what 2 things does the GA modify?

lipids & proteins

what 2 things does the GA produce? where are these things sent to?

glycolipids & glycoproteins. plasma membrane

chain of events from ER to plasma membrane:

\
ER → ____ carry proteins → __ __→ vesicles carry ____ → plasma membrane

vesicles, GA, glycoproteins

the proteins coming from the ER aren’t active until they get where?

GA

how many colors are there in simple stains?

1

how many colors are there in differential stains?

2

are gram stains & acid-fast stains examples of simple or differential stains?

differential

do you stain a specimen before or after fixing it to the slide?

after

what are the 4 general types of stains?

acidic, basic, simple, differential

which type of stain has a negative charge?

acidic

which type of stain has a positive charge?

basic

between negative & positive/basic: which stain stains only the background?

negative

between negative & positive/basic: which stain stains only the object?

positive/basic

what type of stain is a gram stain?

differential

resolution is affected by wavelengths of light (short wavelengths = better resolution) & _____ (how lenses gather light)

aperture

are eukaryotic & prokaryotic cell walls pretty much the same?

no

bacteria may produce 2 types of protein appendages that aid in _____ attachment.

surface

what is the term for the hundreds of short bristle-like proteins extending from the bacterial capsule?

fimbriae

what is the term for the longer & less numerous appendages that connect bacterial cells?

pili

when pili connect bacterial cells, what do they do?

transfer information (like DNA)

who invented the simple microscope?

antonie van leeuwenhoek

what is the centrosome composed of?

2 centrioles next to each other

what are centrioles made of?

array of microtubules

in animal cells, the centrosomes serve as microtubule-organizing centers of the ____ _____ during mitosis.

mitotic spindle

some fungi are multicellular & resemble ____. they aren’t photosynthetic though.

plants

yeast is a fungus. is it unicellular or multi-cellular?

unicellular

do fungi exist in one type of environment or a variety of environments?

variety

mold is a fungus. what 3 things does it cause? what medication does it produce?

micro toxins, decomposition, allergies. penicillin

does a purple/blue stain represent a gram-positive or gram-negative cell?

gram positive

does a pink/red stain represent a gram-positive or gram-negative cell?

gram negative

we see because _____ interact with our eyes.

photons

does the nucleoid appear in prokaryotic or eukaryotic cells?

prokaryotic

the nucleoid region is a condensed area of ___.

dna

does the nucleoid easily stain?

no

what are the small, circular DNA in the nucleoid called? (you insert these into bacterial cells. EX: insulin)

plasmids

where is chromosomal DNA found in prokaryotic cells?

nucleoid

where is plasmid DNA found in prokaryotic cells?

anywhere in the cell

who invented the compound microscope? this person used it to look at insects

galileo

who made the swan-neck experiment?

louis pasteur

describe the swan neck experiment

air could move in & out, but the air particles settled in the bend, keeping the broth sterile

what theory did pasteur disprove with the swan neck experiment?

spontaneous generation

who was the father of western medicine?

hippocrates

who proposed that disease could be caused by small creatures?

varro

who believed that diseases had natural, not supernatural causes?

hippocrates

who observed that survivors of the athenian plague were immune to infection (antibodies)?

thucydides