Exam 1 Lecture 1/2 Flashcards
(42 cards)
Which microbes are most related to each other?
Archaea and Eukarya
What is the typical size of a microbe?
Less than 1mm
Definition of a microbe
A living organism that requires a microscope to be seen
Prokaryotes
Bacteria and Archaea
Eukaryotes
Algae, fungi, protozoa
Virus (attributes from lecture 1)
Acellular, lack many hallmarks of living organisms
True or False: A microscope can ALWAYS be used to determine if a species is Prokaryotic
False
Stromatolites
-date back 3.4 billion years ago - microbial mats of cyanobacteria, grew into thick masses of biofilm - covered shallow seas all over Earth
Modern stromatolites
- distinct communities of different bacteria - high salinity excludes predators
Is a stromatolite a microfossil or bio signature?
Microfossil
What is a bio signature?
chemical and physical signs that could only ave been formed by life - microfossil is a type of bio signature
Robert Hooke
1665 –> discovered “cells” under microscope - did not observe bacteria
Antonie van Leeuwenhoek
1676 –> observed microbes under microscope
Wendell Stanley
purified the first virus in 1899
Alexander Fleming
identified penicillin as the first successful antibiotic in 1929 - penicillin molecule isolated in 1941
When was the first genome sequence?
1995, first genome sequence of bacterium H. influenzas
What is spontaneous generation?
living creatures could arise spontaneously, without parental organisms
Lazzaro Spallanzani
- observed cell fission, 1 bacterium split into 2 - showed that sealed flask of boiled meat broth did not have microbes - 1760’s
Louis Pasteur
Swan-necked flask experiment (1864)
Why was the swan-necked flask important?
It disproved the idea that Spallanzani’s experiment only worked because the flask was sealed, and they thought microbes didn’t grow because there was no oxygen. However, the swan-necked flask allowed the flask to be open to allow air to come in but microbes still didn’t grow. Only when the flask was tiled after a long time, microbes quickly multiplied
What did Lazzaro Spallanzani contribute to microbiology?
Helped disprove the spontaneous generation theory
What did Louis Pasteur contribute to microbiology?
Helped disprove spontaneous generation theory
John Tyndall
Discovered that spores need to be killed with repeated cycles of boiling
What did John Tyndall contribute to microbiology?
Contributed to disproving spontaneous generation