exam 1

microbiology

study of microorganisms or microbes

what are the groups of microbes?

bacteria, archaea, fungi, protists, helminths, viruses, prions

bacteria

prokaryotic, unicellular, pathogenic and nonpathogenic

archaea

prokaryotic, unicellular, nonpathogenic, extreme environments

protists

eukaryotic, uni & multicellular, pathogenic and nonpathogenic

fungi

eukaryotic, uni & multi cellular, pathogenic and nonpathogenic

helminths

eukaryotic, multicellular, can be parasitic

viruses

nonliving, infect host to survive and duplicate rna/dna genome

prions

nonlinving infectious proteins, transmitted by transplant or ingestion, can cause spongiform encephalitis

endosymbiotic theory

eukaryotic cells formed from the mutualism of prokaryotic cells that evolved to function together, chloroplasts and mitochondria were engulfed by primitive pro-eukaryotic cells (both have own dna and 70s ribosomes)

pathogens

microbes that cause disease, less than 1% of all microbes are pathogenic

opportunist pathogens

pathogens that only cause disease in a weakened host or unfamiliar area

robert hooke

mid 1600s, he was the first the publish descriptions of cells

antonie van leeuwenhoek

mid 1600s, refined early versions of the microscope, was the first to see bacteria

spontaneous generation

long-held notion that life comes from nonliving items

biogenesis

the fact that life emerges from existing life, the opposing argument to spontaneous generation

louis pasteur

in the 1800s, proved biogensis and disproved spontaneous generation in flask experiment, microbes are in the air

- invented pasteurization to kill off yeast in wine

- developed first vaccine for anthrax and rabies

robert koch

in the late 1800s, developed the germ theory of disease based on idea that specific microbes cause specific diseases

- also developed staining techniques and media for observing bacteria

- discovered etiology of anthrax, bacteria Bacillus anthracis

germ theory of disease

microbes cause infectious diseases

ignaz semmelweis

in the 1800s, told doctors they should wash hands and disinfect surfaces between patients, develop aseptic techniques in the hospital setting

- his theories caused the rate of mortality by childbirth fever to drastically decrease

joseph lister

in the mid 1800s, pushed the importance of sanitizing wounds and surgical sites

- did work with carbolic acid to prevent pus formation

HAI

healthcare acquired infection or nosocomial infections that are spread through the healthcare facility through healthcare workers, this is greatly limited by practicing aseptic techniques

taxonomy

“don’t kill phyllis“ corny office girl got scared

domains

bacteria, archaea, eukarya

kingdoms

archaea, bacteria

eukarya: fungi, plantae, animalia, protists

eukaryotic species

a group of similar organisms that can sexually reproduce together, have a nucleus

prokaryotic species

cells that share physical characteristics with at least 70% dna similarity and 16S rRNA sequence similarity, do not have a nucleus

binomial nomenclature system

developed by carl linnaeus, a two name system to categories all living things scientifically

Genus species

malaria

mosquito-borne disease caused by a protozoan called plasmodium

- kills over 600k people a year

- those with sickle cell anemia have a harder time acquiring the disease because of the shape of their rbcs

biofilms

sticky communities formed by a single or diverse microbial species

- ex: teeth (plaque), contact lenses, water filter units, cutting boards, catheters

basic dyes

one of the most commonly used stains, positively charged, cell appears color of dye

acidic dyes

negative staining, negatively charged, stains background

mordants

chemicals that could be required in certain staining procedures that interact with a dye to fix or trap it on/inside a treated specimen

gram stain

a type of differential stain that classifies bacteria as gram- postive or negative (pink)

gram stain technique

1. crystal violet (primary stain) is added to a heat fixed bacterial smear

2. iodine (mordant) is added to form an insoluble crystal violet-iodine complex (CD-I complex)

3. acetone-alcohol (decolorizing step) is used to rinse the sample

4. safranin (counterstain) is added to the sample

cation

atoms that have lost electrons and have net positive charge

anion

atoms that have gained electrons and have net negative charge

acids

add [H+] ions

bases

add [OH-] ions

pH

-log[H+]

exergonic reactions

when more energy is released than was used to start the reaction

endergonic reactions

when more energy is used during the reaction than released, products have higher energy than reactants

building blocks of proteins

amino acids, bonded w peptide bonds covalently

peptidogylcan

part of cell wall in bacteria

capsule

smooth glycocalyx arrangement, help cells adhere and avoid pathogens

mycolic acid

waxy that surrounds acid-fast bacteria (ex. leprosy & tb), increases bacterial pathogenicity

what type of ribosomes do prokaryotes have

70s ribosomes

pleomorphism

very small cells that don’t have a cell wall so they are able to take on any shape, increases survival rate and is important for transmission into hosts

binary fission steps

1. dna is copied

2. cell grows

3. copied chromosome is drawn to opposite sides of the cell

4. septum begins to form at midpoint

5. septum divides the cells, making 2 daughter cells

diffusion

passive movement of substances from higher to lower concentrations

simple diffusion

substances move from higher to lower concentrations, may require transporter (facilitated diffusion)

active transport

substances move from low to higher concentrations, requires transporter and energy

osmosis

the movement of water from higher to lower concentration

chemotaxis

the movement of prokaryotic cells in response to a chemical stimulus

gram positive cell walls

THICK layer of peptidoglycan, no outer membrane, has teichoic and lipoteichoic acids

gram negative cell walls

THIN layer of peptidoglycan, lipid rich outer membrane that contains LPS and porins, more resistant to bacteria bc of outer membrane

gram negative acetone-alcohol treatment reaction

dissolves outer membrane, damages thin peptidoglycan layer, and CV-I washes out

gram positive acetone-alcohol treatment reaction

slightly damages thick peptidoglycan, less permeable bc of dehydration, CV-I is retained

fimbriae

help bacteria cells attach to various structures, important in biofilms, common in gram- bacteria

pili

- adheres to surfaces, transport, and helps in gene transfer thru conjugation

longer than fimbrae, more rigid, and less numerous

pseudomurein

found in archaea cell walls

endospores

dormant form of bacteria, forms when bacteria is stressed

- very resistant to environmental stresses

what type of ribosomes do eukaryotes have

80s ribosomes

mycology

the study of fungi

mycoses

diseases caused by fungi

dermatophytes

mycoses that are true pathogens, infect the hair/skin/nails

- infections are called tinea scientifically

dimorphic

in fungi, can be mold or yeast like depending on the environment

- include many pathogenic fungi

phagocytosis steps

1. attachment of microbe to membrane

2. ingestion of molecule/microbe into a phagosome

3. phagosome fuses w a lysosome to form phagolysosome

4. digestion

5. residual waste is discarded

endocytosis

the process of moving substances into the cell

exocytosis

the process of moving substances out of the cell

plasmodium

causes malaria

helminths

parasitic worms

genome

the entire collection of genetic material in a cell or virus

dna structure

double stranded and anti-parallel arrangement (strands run opposite 5’ to 3’ and 3’ to 5’), and

parts of a nucleotide

phosphate group, sugar (deoxyribose for DNA), and nitrogen base

mRNA

has codons that code for amino acid or stop signal

tRNA

has anticodon loop that is complimentary in codone and brings amino acids to a ribosome during translation to build proteins

rRNA

folds into 3d structures and combines w proteins to form ribosomes

dna replication steps

1. topiosomerase unwinds the dna

2. helicase breaks hydrogen bonds between the dna strands

3. single stranded binding proteins keep strands apart

4. leading strand=dna polymerase binds to primer and continuously copies from 5’ to 3’

5. lagging strand=dna polymerase binds to. several primers and copies in short fragments from 5’ to 3’

6. dna ligase seals the fragments together

exons

regions in dna that code for genes

introns

regions in dna that are non-gene regions, do not code for genes

- cut out by snurps

start codon

AUG

what is the first amino acid brought to the ribosome

MET

subsitation mutation

when an incorrect nucleotide is added

insertion mutation

when a cell adds one or more nucleotides to genome sequence than needed

deletion mutation

when one or more nucleotides is removed from the genetic sequence

operons

collection of genes controlled by shared regulatory element

transposons

jumping genes

virus structure

- acellular

- have capsid (protein coat)

- have dna/rna

- some have envelopes (some have spikes)

- glycoprotein extensions (help virus get into cell)

antigenic drift

frequent mutations that cause minor changes in the virus spikes, influenza with HA and NA spikes

antigenic shift

one major mutation of genetic reassortment, can lead to increased infections or an expanded host range

bacteriophage

viruses that infect bacteria

tropism

tissue or cell specificity regarding viral surface factors

acyclovir

type of nucleoside analog that can be used to treat herpes by inhibiting DNA replication

animal virus life cycle

animal virus replication pathway

1. attachment

2. penetration

3. uncoating

4. replication

5. assembly

6. release

glycocalyx

sticky carbohydrate-rich layer surrounding cell

eukaryotic species

similar organisms that can sexually reproduce together, have a nucleus

prokaryotic species

cells that share physical characteristics≽70% dna similarity, ≽95% identical rRNA sequence similarity, nu nucleus

acid fast bacteria

waxy cell walls that have a lot of mycolic acid