Chapter 1: Evolution of Microorganisms and Microbiology Flashcards
Learning Objective
Define microorganism/microbe.
- life forms too small to be seen by the human eye
What are facts of microbes?
- diverse in form/function
- inhabit every environment that supports life
- many single-celled, some form complex structures, some multicellular
- live in microbial communities
Learning Objective
What are the 5 major reasons to study microbes?
- Today’s microbes are the closest relatives to the oldest form of life
- Major fraction of the Earth’s biomass
- Microbial Ecology
- The human microbiome affects human health
- Microbes and food
Closest relative to the oldest form of life.
How old is the earth?
When did the first cells appear?
- 4.6 billion years old
- between 3.8 and 4.3 billion years ago
Closest relatives to the oldest form of life.
T/F: The atmosphere was anoxic before microbes shaped the environment.
TRUE – only anaerobic metabolisms were present as first
Closest relatives to the oldest form of life.
When did the first anoxygenic phototrophs exist?
Cyanobacteria (oxygenic phototrophs)?
- 3.6 billion years ago
- 2.6 billion years ago
Closest relatives to the oldest form of life.
What does LUCA stand for?
Last Universal Common Ancestor
Major Fraction of Earth’s biomass.
T/F: The are more microbial cells on Earth than known stars in the universe.
TRUE – there are about 10^30 microbial cells on Earth
Microbial Energy
Define Microbial Ecology.
- how microbes affect animals, plants, and enitre global ecosystem
Microbial Ecology
List 4 effects that microbes can have.
- cause disease
- benefits animals and plants
- can be used as drugs or immunizing agents
- used in water and wastewater treatment
Human microbiome.
Define Microbiome.
- a group of microbes that live stably on/in the human body
Human microbiome.
What are 3 functions of the human microbiome?
- help to maintain good health
- can prevent growth of pathogenic microbes
- may help trainf the immune system to discriminate threats
Human microbiome.
T/F: The adult human body is composed of 30 trillion cells, and the body harbors another 40 trillion bacterial cells.
TRUE
Microbes and food.
What are the negative impacts of microbes?
- food spoilage and foodborne disease
Microbes and food.
What are the positive impacts of microbes?
- improved food safety
- preservation
- contribute to flavor
Learning Objective
List 4 types of cellular microbes.
- fungi
- protists
- bacteria
- archaea
Learning Objective
List 4 types of acellular microbes.
- viruses
- viroids
- satellites
- prions
Cellular vs Acellular
Give 2 examples of fungi.
- yeast
- molds
Cellular vs. Acellular
Give 3 examples of protists.
- algae
- protazoa
- slime molds
Cellular vs. Acellular
Give an example of bacteria.
- escherichia coli
Cellular vs. Acellular
Give an example of archaea.
- methanogens
Cellular vs. Acellular
What are viruses composed of?
- protein and nucleic acid
Cellular vs. Acellular
What are viroids composed of?
- RNA
Cellular vs. Acellular
What are satellites composed of?
- nucleic acid enclosed in a protein shell
Cellular vs. Acellular
What are prions composed of?
- protein
Learning Objective
Describe Carl Woese importance to microbiology.
was the first to identify a third form of life (archaea) by comparing ribosomal RNA (rRNA) sequences
- found that all evolutionary relationships between all cells could be revealed by rRNA analysis
(Blank) is encoded by DNA.
Genetic information
(Blank) synthesize protein.
Ribosomes
Define cytoplasm/cytosol.
aqueous mixture of macromolcules, small organics, ions, and ribosomes inside cells
Define plasma membrane.
selectively permeable layer composed of phospholipids and proteins
Learning Objective
What type of organisms are prokaryotes?
bacteria and archaea
Learning Objective
What type of organisms are eukaryotes?
plants, animals, algae, protozoa, and fungi
Learning Objective:
Prokaryote vs Eukaryote:
Ribosomes?
- 70s ribosomes
- 80s ribosomes
Learning Objective
Prokaryote vs Eukaryote:
Membrane enclosed organelles?
- prokaryotes = no
- eukaryotes = yes
Learning Objective
Prokaryote vs Eukaryote:
DNA storage?
- prokaryotes = typically one compact, circular chromosome
- eukaryotes = larger genomes composed of linear chromosomes
Learning Objective
Prokaryote vs Eukaryote:
Replication?
- binary fission
- mitosis and/or sexual reproduction
Learning Objective
Prokaryote vs Eukaryote:
Cell Wall?
- prokaryotic = yes
- eukaryotic = no
Learning Objective:
Bacteria v Archaea v Eukarya:
Single-cell or multicellular?
- bacteria = single-cell
- archaea = single-cell
- eukarya = single-cell or multicellular
Learning Objective
Bacteria v Archaea v Eukarya:
Prokaryotic structure?
- bacteria = yes
- archaea = yes
- eukarya = no