BIO 2015 Bideshi EXAM 1

microorganism=microbe

any organism too shall to be observed by the naked eye, includes viruses can be observed by light and electron microscopy

infection

the relationship between two organisms and the competition for supremacy that takes between them

disease

any change from the general state of good health

Pathogen

any microbe that causes disease

Etiology

koch focused on this, or disease causation

Germ Theory of Disease

microorganism responsible for disease

Robert Hooke

coined the term "cell", showed microscope was an important tool for studying the "very small"

Leeuwenhoek

"discoverer of the microbial world," described hundreds of moving particles he called animalcules, suggested maggots arose from eggs in the decaying material, not the material itself

Abiogenesis

a "vital force" in substances produces life, examples meat produces maggots, grains produce mice, mud produces fish

Biogenesis

life arise from pre-existing life

Redi

found that it flies were prevented from landing on meat, it did not produce maggots

Swan neck flask experiment

Infusion put into flask with "S" shaped neck

Infusion is boiled to kill all microorganisms

Microorganisms trying to enter the flask are stuck in the "S" curves of the neck

When flask is tipped the trapped microorganisms are allowed to enter the sterile infusion

Microorganisms quickly multiplied in the infusion

Koch's Postulates

Ehrlich

originated the concept of selective toxicity: Target specificity

Lister

sterile surgeries, suggested that microbes were responsible for gangrene and other surgical complication, developed the practice of antisepsis, chemical disinfection of external living surfaces used carbolic acids to decontaminate wounds and surgical instruments

Fleming

serendipitous discovery of penicillin ushered the era of antibiotics

amino acids

proteins

simple sugars

carbohydrates

fats, oils

lipids

A, G, C, T, U

DNA, RNA

Eukaryotes

have nucleus, have organelles

prokaryotes

no nucleus, no organelles

Similarities of prokaryotic and eukaryotic cells

genetic organization with DNA in chromosomes, compartmentation with cell membranes, metabolic organization in the cytoplasm, protein synthesis with ribosomes

All eukaryotic cells have

membrane enclosed organelles including an endomembrane system; some bacteria have microcompartments

Endoplasmic Reticulum

transport proteins (rough ER), synthesize and transport lipids (smooth ER)

Golgi apparatus

modify, sort, and package proteins

Lysosomes

digest proteins, control cell metabolism and growth

eukaryotic cytoskeleton

gives the cell structure and transports materials within the cell

Parkaryotic Cells have cytoskeleton

cell shape, positioning structures within the cell

flagella in eukaryotic cells

made of microtubules and beat in a wave-like motion

flagella in prokaryotic cells

structurally different and provide rotational propeller-like force

Cilia (only in eukaryotes)

shorter microtubules and more numerous than flagella

Taxonomy

science classification, involving arranged related organisms into logical categories

Carolus Linnaeus

published Systema Naturae, establishing a uniform system for naming organisms

nomenclature

gives scientific names to organsims

binomial system

includes two words

genus species

scientific "naming" of Organism

Archaea

Prokaryotes with unique rRNA sequences

Bacteria

All other prokaryotes

Eukarya

includes the multicellular kingdoms of plants, fungi, and animals, as well as the single called protists

Woese & Fox

proposed classification scheme with the most inclusive category being the domain

multicellular development

cells cooperate with each other as seen in biofilms, bacterial communal associations

quorum sensing

cells communicate with each other through a chemical

light microscopy

used to observe most microorganisms,

darkfield microscopy

shows the specimen against a dark background and provides good resolution

fluorescence microscopy

specimens are coated with fluorescent dye and illuminated with ultraviolet light

Confocal microscopy

with a laser as it's source of illumination Laser is focused on a single point at a SPECIFIC depth Pinhole aperture in the detector allows only fluorescence emitted from

the exact point of focus to be imaged

Transmission Electron Microscopy (TEM)

limit 10-15 A

Scanning Electron Microscope (SEM)

Resolving Power 3-20 nm

calculating resolving power

d=(0.61)(wavelenth)/(1.5)

simple stain

use of a single basic dye

negative stain

acidic dyes, cell unstained

gram stain

stained with crystal violet and gram's iodine solution and washed with a decolorizer

gram positive

bacteria retain the crystal violet where gram negative does not

Bacteria shapes

spheres (cocci), rods (bacilli), and spirals

Archaea do not

cause human disease

pili

are structures used for attachment and bacterial conjugation

fimbrae

pilin with adhesins, attachment specificities

conjugation (sex) pili

genetic transfers, antibiotic resistance genes

prokaryotic flagella

long appendages extending from the cell surface, used for cell motility, chemotaxis, and attachment, prokaryotic flagella contain a helical protein filament, hook, and a basal body

Spirochetes contain endoflagella

which move the cell through torsion exerted on the cell by endoflagellar rotation

glycocalyx

an outer layer external to the cell wall

Functions of Glycocalyx

glycocalyces are virulence factors, protect bacteria from phagocytosis, bacteria to attach to surfaces/tissues, prevent dehydration

prokaryotic cell wall

tough and protective external shell, protects from injury and maintains cell shape and water balance

Gram-positive bacteria

have thick peptidoglycan cell walls containing teichoic acid

gram-negative bacteria

have a two-dimensional peptidoglycan layer and no teichoic acid

cell membrane is

a permeability barrier

the cytoplasm is

the center of biochemical activity

Most bacteria reproduce by

binary fission

generation (or doubling) time

the interval of time between successive binary fissions

lag phase

no cell division occurs while bacteria adapt to their new environment

exponential growth

population occurs during the logarithmic (log) phase, Human disease symptoms usually develop during the log phase

stationary phase

when reproductive and death rates equalize

Decline (exponential death) phase

when the accumulation of waste products and scarcity of resources causes the population to enter

endospores

are a response to nutrient limitation, highly resistant structure formed by species of bacillus and clostridium when nutrient supplies are low

calculate number of bacteria

multiple by 2

anaerobes

do not or cannot use oxygen

Facultative prokaryotes

grow either with oxygen or in reduced oxygen environments

capnophilic

bacteria require an atmosphere low in oxygen and rich in carbon dioxide

acidophiles

are acid-tolerant prokaryotes

thermophiles

multiply best around 60 degrees celsius, living in compost heaps and hot springs

Mesophiles

thrive at the medium temperature range of 10 to 45 degrees Celsius, including pathogens that thrive in the human body

Pyschrophiles

grow optimally between 15 degrees celsius and make up the largest portion of all prokaryotes on Earth

Hyperthermophiles

Archaea that grow optimally above 80°C, found in seafloor hot-water vents

synthetic medium

chemical composition of the medium is known

metabolism

all biochemical reactions that take place in cell

anabolism

build up process of molecules, small molecules to large molecules

catabolism

break down process