microscopy + kingdom bacteria & archaea

slideshow + tophat vocab

magnification

enlarges the image of a specimen

mordant

a substance used to set or fix dyes, helping the stain stick strongly to the cells

cyanobacteria

group of photosynthetic bacteria, often called blue-green algae, that make their own food using sunlight and release oxygen 

binary fission

when one cell duplicates + divides into two cells identical to the parent cell

symbiotic

close, long-term relationship where two different species live together + interact

stage

the platform where the specimen slide is placed for viewing

light source

provides the light needed to shine through + view a specimen

diaphragm

controls the amount of light reaching the specimen

focus

used for small, precise focusing adjustments, especially under high power

coarse adjustment knob

moves stage up and down

fine adjustment knob

the process of adjusting the lens system to create a clear image

resolution

ability of a microscope to distinguish two close points as separate entities (actual result)

objective lens

lens closest to the specimen that captures light + provides the initial, primary magnification of the image

ocular lens

the lens at the top that you look through, which further magnifies the image (10x)

what are the two types of microscopes used in this lab

compound, stereo

compound microscope

allows us to see objects that are too difficult or small to see with the naked eye

condenser

focus the light on the specimen

iris diaphragm

built into condenser, regulates amount of light passing through specimen

revolving nose piece

supports objective lenses

scanning objective on compound microscope

4x

low-power objective on compound microscope

10x

high-power objective on compound microscope

40x

oil-immersion objective on compound microscope

100x

stereo microscope

used to view relatively large objects, somewhat visible at the naked eye

objective lens on stereo microscope

2x or 4x

total magnification

ocular lens magnification x objective lens magnification (10 x _)

resolving power

ability to distinguish two objects close together or two points/lines in an object under the microscope (theoretical potential)

working distance

distance between the specimen + the objective lens, decreases as magnification increases

field of view

circle of light or visible area when looking through eyepiece, decreases as magnification increases

field of view equation

diameter of FOV (mm) x 4(scanning lenses mag.) / objective mag.

depth of field

the vertical distance with which structures are in sharp focus, decreases as magnification increases

taxonomy

science of classifying organisms according to their degree of similarity

taxonomic categories

domain, kingdom, phylum, class, order, family, genus, species

scientific name

consists of both the genus + species name of an organism

kingdom archaea

• relatively rare organisms

• thrive in extremely harsh environments

• genetic material more closely related to eukaryoties than bacteria

bacteria characteristics

• prokaryotes

• unicellular, some colonial

• contain a cell wall exterior to cell membrane

• some move with a flagella

prokaryotes

lack a true nucleus + other membrane bound organelles

bacillus bacteria

rodlike shape

coccus bacteria

spherical shape

spirillum bacteria

sprial shape

heterotrophs

obtain organic nutrients from environment

sapotrophs

nutrients obtained from decaying or dead organisms

examples of heterotrophs

sapotrophs, parasites

autotrophs

produce their own food

asexual reproduction in bacteria

binary fission, just like mitosis

sexual reproduction for bacteria

conjugation — genetic material exchange through a tube

you can control bacterial growth using…

antibiotics, antiseptics, disinfectants

antibiotics

chemical dervied from certain organisms, used to inhibit growth of microorganisms + prevent/treat infectious diseases

antiseptics

substances used to control the growth of disease-causing microorganisms on living tissue

disinfectants

control bacterial growth on inanimate objects

zone of inhibition

• circular area around the spot of the antibiotic in which the bacteria colonies don’t grow

• can be used to measure the susceptibility of the bacteria towards the antibiotic

• the larger the ZOI diameter, the better the antibiotic

two types of bacterial cell walls

gram-positive, gram-negative

peptidoglycan

• tough, mesh-like polymer made of sugars + amino acids that wraps around the cell membrane of most bacteria forming a cell wall

• gives the bacterial cells their shape + protects them

gram-negative bacteria characteristics

• more complex cell walls

• cell walls contain less peptidoglycan

• contains an outer lipopolysaccharide layer

• appears pink after gram staining

gram-positive bacteria characteristics

• cell walls rich in peptidoglycan

• no outer lipopolysaccharide layer

• appear blue after staining

eukaryotic

cells that have a nucleus surrounded by a membrane containing their dna

kingdom monera

referes to the fact that most of its members are single-celled organisms

domain

the highest most broad category of biological classification ranking above kingdom