Lecture 1- what is microbiology? Flashcards
what is microbiology?
the study of organisms too small to be seen with the naked eye
why is microbiology so important? 5
-microbes are the oldest form of life
-largest mass of living material on earth
-biogeochemical cycles
-live in places unsuitable for other organisms
-microbes are an important factor of the ecosystem
what are the 7 things all cells have in common? prokaryotes eukaryotes
cytoplasmic membrane
cytoplasm
genetic material
genome
chromosome
plasmid
ribosomes
genetic material function
all cells store their genetic information as DNA, the information is divided into genes
what is a genome
a cells full complement of genes (the arrangement of genes tells us lots about the cell)
what is a plasmid
a piece of DNA that carries non-essential genes (ex. genes for antibiotic resistance)
ribosome function
site of protein synthesis
what is protein synthesis?
process of creating protein molecules
how does protein synthesis work?
starts in the nucleus:
DNA –> transcription –> RNA –> splicing –> mRNA
mRNA gets exported to the cytoplasm:
mRNA –> translation –> mRNA decoded –> folds up –> protein!!!
what are the 3 main types of “microbes”?
eukaryotes
prokaryotes
viruses (not a microbe)
what are 5 unique things about eukaryotes? what is the internal structure like? how do they divide? what do they use for energy?
membrane bound nucleus
membrane bound organelles
complex internal organization
division by mitosis and meiosis
almost all eukaryotic cells can use glucose for energy and can store some form of glucose for energy
what are 2 examples of eukaryotes?
protists
fungi
what are protists? are they multicellular or unicellular?
unicellular or multicellular without differentiation into tissues
what are 3 examples of protists?
protozoa: animal- like microorganism
algae: photosynthetic plant- like microorganisms
slime molds and water molds: filaments
what are characteristics of fungi?
unicellular (yeasts)
filamentous (molds)
multi- cellular (mushrooms)
what are 5 unique things about prokaryotes? how do they divide? multi or unicellular? what is the internal structure like?
no membrane bound nucleus or organelles
generally smaller
simple internal structure
divide by binary fission
most are unicellular
what are 2 examples of prokaryotes?
bacteria
archaea
what are 4 unique things about viruses?
acellular infectious particles
extremely small (smaller than prokaryotes)
obligate intracellular parasites
lacks independent metabolism, therefore, dependent on the host metabolism
viruses lack an independent metabolism, what does that mean?
no ribosomes or ribosomal RNA
cant be classified with other microbes because they have no cells of their own
what is different about a prokaryotic cell compared to a eukaryotic cell?
no nucleus
no mitochondria
no endoplasmic reticulum
in practice, what should species of bacteria and archaea have? (3)
most characteristics in common
greater than 97% sequence similarity in the 16S RNA gene
high degree of genome similarity (DNA-DNA hybridization)
what are the 3 domains of life that all organisms get classified into?
bacteria
archaea
eukarya
how do we classify what domain an organism goes into?
we look at genetic differences rather than morphological (appearance) differences
what is more diverse; microorganisms or plants and animals?
microorganisms! (some are even visible to the naked eye)