microbiology - exam 1

microbe

organism that requires microscope to be seen

Pelomyxa sp., a large ameba

Escherichia coli bacteria

Methanocaldococcus jannaschii, archeaon

Human papillomavirus

pathogens/germs

microbes that cause disease

(bacteria, viruses, and fungi)

principal cause of human mortality

diseases caused by pathogens

microscope

instrument that uses one or more lenses to magnify the image in our eyes

first microscopist to publish a systematic study of world as see under a microscope

Robert Hooke

compound microscope + who created it

created by Robert Hooke

a magnifying instrument containing two or more lenses that multiply their magnification in series

Micrographia

the first publication that illistrated objects observed under a microscope

Illustration of mold sporangia, drawn by Hooke from his observations of objects with a compound microscope

who was the first to observe distinct units of living material, calling them “cells”

Hooke

first to observe bacteria with a single lens, first to observe single celled microbes

Leeuwenhoek

Leeuwenhoek’s microscope

spiral bacteria viewed through a replica of Leeuwenhoek’s instrument

how are microbes classified

members of a species, according to shared set of genes and traits

fundamental basis for classifying all life forms

genome - a total DNA sequence content of organism

major trait distinguishing microbes

possession or lack of a membrane-enclosed nucleus

prokaryote

an organism whose cell or cells lacks a nucleus

eukaryote

an organism whose cell contains a nucleus

bacteria and archaea

prokaryotes

fungi, protozoa, and algae

eukaryotes

the 3 domains

bacteria, archaea, & eukarya

some archaea are extremophiles… what does that mean?

live in seemingly hostile environments

methanogens

archaea whose metabolism releases methane

what do archaea NOT do

cause disease

protozoa

a heterotrophic eukaryotic microbe, usually motile

algae

eukaryotic microbes containing chloroplasts that conduct photosynthesis

protists

a single-celled eukaryotic microbe, usually heterotrophic and motile

fungi

heterotrophic organisms, usually nonmotile, grow by absorbing nutrients from surrounding

parasites

organisms that live at the expense of a host they inhabit

viruses

noncellular microbe that contains a genome and can only replicate inside a host

how do viruses replicate

a virus particle contains genetic material that takes over the metabolism of a cell to generate more virus particles

how did humans use microbes before discovering them?

made food and used lithotrophs (rock-eating bacteria) to mine

the “golden age” of microbiology as a science

19th century (1847-1899)

antibiotics

a molecule that can kill or inhibit the growth of selected microorganisms

leading cause of death in children

microbial infections

Catherine of Siena

patron saint of nurses, nursed victims of plague and leprosy

spontaneous generation

the theory that living microbes can arise spontaneously, without parental organisms

Lazzaro Spallanzani

disproved spontaneous generation of microbes by showing a sealed flask of meat broth sterilized by boiling failed to grow microbes & discovered cell fission by watching one microbe split into two

Louis Pasteur

disproved spontaneous generation with a swan-neck flask and discovered fermentation is actually caused by a living yeast

Pasteur’s swan-neck flask

After boiling, contents remained microbe free, despite access to air

John Tyndall

showed that repeated cycles of heat are necessary to elimate spores formed by certain kinds of bacteria

endospores/spores

heat-resistant form of bacteria