Micro Exam #1

Janssens

created the first compound microscope

Robert Hooke

observed the first cell and also created the cell theory

Leeuwenhoek

observed the first bacteria

spontaneous generation

belief that organisms could arise spontaneously from non-living matter

Redi

Needham

Spallanzani

Pasteur

Robert Koch

responsible for the “germ theory”

Koch’s Postulates

• microbe must be present in every case of disease

• microbe must be isolated from host w/ disease

• pure culture of microbe must cause disease in healthy susceptible host

metabolism

chemical transformation of nutrients

growth

use of nutrients to grow and propagate

evolution

genetic changes transferred to offspring

differentiation

some microbes modify structures to form specialized cells

intercellular communications

some microbes respond to other microbes

exchange DNA

swap or take up DNA

motility

many cells move through self-propulsion

eukaryotes

membrane-bound organelles (humans)

prokaryotes

do not have membrane bound organelles (bacteria)

cocci

spherical shaped bacteria

bacilli

rod-shaped bacteria

spiral

one or most twists in a bacteria shape

vibrio

comma shaped bacteria

spirilla

helical w/ rigid body

spirochete

helical and flexible

diplo

two cocci

street

multiple cocci in a chain

tetrad

four cocci

sardine

eight cocci in a cube

staphylo

multiple cocci in a “grape” like cluster

single

one bacillus

diplo

two bacilli end to end

strepto

multiple bacilli chained end to end

coccobacillus

one bacillus that looks somewhat spherical and rod-shaped

monomorphic

bacteria that has only one shape

pleomorphic

bacteria that have many shapes

glycocalyx

sugar coat - gelatinous substance around the outside

capsule

the neat form of a glycocalyx - around 1 cell

slime layer

the jankity form of a glycocalyx - around 1 cell

biofilm

form of glycocalyx that surrounds multiple bacteria - often found in teeth plaque

flagella

structure that assists in motility of bacteria

peritrichous

has flagella all around the cell - looks hairy

monotrichous

one flagellum at the pole

lophotrichous

multiple at one pole (tuft of grass)

ampitrichous

one or more flagella at two poles (think amphibian)

endoflagella

• bundle of flagella underneath the outer cell membrane

• only found in spirochetes

• allows them to move in corkscrew fashion

fimbriae

filamentous protéine structures that enable organisms to stick to surfaces and each other

pilli

• can facilitate genetic exchange between cells

• type 4 adhere to host and supports twitching motility

peptidoglycan

multiple layers of modified sugars connected by polypeptides

gram positive

gram negative

LPS

• found only in G-

• contains lipid A toxin

  • endotoxin buried in the outer membrane

• when immune system lyses cell, lipid A is released

nuclei

region of the bacteria that contains chromosomes

supercoiling

nuclei-associated proteins bend and fold DNA

plasmids

extrachromosomal DNA - confer special properties not required for growth or reproduction

endospores

• resistant to heat, harsh chemicals, UV radiation, and desiccation

• survival structures to endure unfavorable growth conditions in bacteria

virus

• acellular infections agents

• absolutely dependent on a living host

vision

completely assembled infectious viral particle that can infect new cells

structural protein

• proteins that make up the virion

• may one part of capsid, in envelop, or associated with the genome

non-structural protein

• usually required for replication but re not part of the vision

capsid

large protein structure made up of many capsomeres and acts to protect viral nucleic acid

helical

long “slinky” capsid

icosahedral

relatively circular capsids - repeating shapes

complex

funky shaped capsid (cookie bot=bacteriophage)

envelope

a lipid bilayer, stolen from the previously infected host that surrounds the capsid

attachment protein

extends from the capsid and is used to attach to host cells

receptor

specific protein that the attachment protein must contact to infect the cell

Lytic Cycle

• attachment

• entry/penetration

• biosynthesis

• assembly/maturation

• release

Attachment

• step one of lytic cycle

• between a protein and specific receptor

Entry

• step two of lytic cycle

• genome enters cell cytoplasm

• occurs due to envelope and cell membrane fusing or by puncturing a hole

Biosynthesis

• step three of lytic cycle

• viral proteins and genome copies are synthesized

• early and late proteins

early proteins

usually take over host cells (does prep)

late proteins

structural to assemble and escape

Assembly

• step 4 of lytic cycle

• viral proteins and genome come together to form virion

• works like magnetic building blocks

Release

• step five of lytic cycle

• virion is released from the host cell

lysis

cell breaks open (dies) to release visions

exocytosis

cell packages the virus and sends it out

budding

virus is pushed out of the cell and gets an envelope on the way out

lysogenic cycle

• after entry, the virus integrates its DNA into the host cell

• usually used when conditions are unfavorable

• basically virus sits dormant until favorable conditions arise

antigenic drift

• all viruses

• evolve causing small changes in antigens so the immune system doesn’t recognize the virus as well

antigenic shift

• only in segmented viruses

• can swap genome segments in progeny to dramatically change antigens so the immune system cannot recognize the virus

prion

• normal cellular protein

• found only in mammals brains

• may have a role in regulating cell death

infectious prion

• misfolded protein that cases disease

• can be acquired or can be a random misfolding

viroid

• no protein only RNA

• RNA can fold and function like a protein

• only found in plants

• spread via aphids

fungi

• typically multicellular (mold), some unicellular (yeast)

• usually non-motile

• hypertrophic

hypertrophic

only consume organic material

haploid

one set of each chromosome in 1 nuclei

diploid

two sets of each chromosome, one from each parent, in 1 nuclei

dikaryotic

two sets of each chromosome, one from each parent, in two separate nuclei

plasmogamy

fusion of plasma membranes

karyogamy

fusion of the nuclear membrane

saprophytes

for food from dead organic matter

parasites

consuming organic matter while its still alive

mutualists

helps the plants out in exchange for products of photosynthesis

Lichens

combo of both fungi and cyanobacteria - bacteria produces sugar, fungi provides protection, attachment, and nutrients

mycosis

any fungal infection

algae

• unicellular (green) or multicellular (brown) eukaryotes similar to plants

• phototrophs - produce own food from light

• most are aerobic and live in water

protists

• unicellular eukaryotes similar to animal cells

• heterotrophs - consume organic material

• more likely to be human pathogens

• most are aerobic and live in soil/water

binary fission

type of protist reproduction in which one cell replicated into 2 daughter cells

budding

protist reproduction where one cell buds off parents with a copy of the genome