Chapter 1 Flashcards
Prokaryote
lack a true membrane-delimited nucleus
not compartmentalized
eukaryote
have a membrane-enclosed nucleus
more complex morphology
Definition of life
metabolism
growth
reproduction
genetic variation/evolution
response/adaptation to environment
homeostasis
composed of cells
evolution of classification schemes
Two groups: animals vs plants
Five kingdoms: MOnera, Protista, Fungi, Animalia, Plantae
Three Domain system: Bacteria, Archaea, Eukarya
Bacteria
single cell
cell walls with peptidoglycan
prokaryotic
ubiquitous
do not reproduce sexually
Archaea
unique RNA sequences
lack peptidoglycan- have unique membrane lipids
unusual metabolic characters
live in extreme environments
do not reproduce sexually
Eukarya
generally larger
plants, animals, microorganisms classified as protists or fungi
Viruses
Acellular
smallest of microbes
very simple- consist only of proteins and nucleic acids
requires a host cell to replicate
cause a wide range of disease
Viroids and Virusoids
infectious agents composed of RNA
Prions
infections proteins
Ribozyme
RNA molecules with the ability to catalyze reactions
performs cellular work and replication
Micelle
a single lipid layer
Ribozymes place in evolution
Early conditions formed RNA and micelles
they came together in a primitive cell using RNA to store genetic info and code
primitive cells eventually changed to use DNA to store genetic info
cell theory
all living things are composed of cells
spontaneous generation
living organisms can develop from non-living or decomposing matter
Indirect evidence to support germ theory
3 non human systems
- Bassi
- Berkeley
- de bary
Pasteur- (microorganisms carried out fermentation)
semmelweis
Lister
Snow
Direct Evidence to support Germ theory
Koch
Koch postulates
- microorganisms must be present in every case of disease but absent from healthy individuals
- suspected microorganism must be isolated and grown in a pure culture
- same disease must result when the isolated microorganism is inoculated into a healthy host
- same microorganism must be isolated again from the diseased host
limitations of Kochs Postulate
some organisms cannot grow in pure culture
using humans in completing the postulates is unethical
molecular and genetic evidence can be used instead
Developments that were the direct result of Kochs postulates
Aga
petri
nutrient broth and agar
methods for isolating microorganism
aseptic technique
Porcelain bacterial filters
magic bullet
attack only prokayotic cells but not eukaryotic
