Chapter 23 - Bacteria and Archea Flashcards
2 domains of prokaryotes
Archae and Bacteria
Archae and Bacteria
2 domains of prokaryotes
How big are most prokaryotes
Microscopic but grow in large quantities
How many prokaryotes would be in a handful of fertile soil
More than the amount of people that have ever lived
Where do prokaryotes thrive
Everywhere, even area uninhabitable by other organisms
Are prokaryotes unicellular or multicellular
They are unicellular but grow in colonies
How big are most prokaryotic cells
.5-5 micrometers
How big are most eukaryotic cells
10-100 micrometers
What are the three common shapes of bacteria
Cocci, bacilli, and spirillum(spiral)
Cocci
Spherical shaped prokaryote
Bacilli
Rod shaped prokaryote
Spirillum
Spiral shaped prokaryotes
What other shape of prokaryote exists
Square shaped
What cell structure is present on nearly all prokaryotes and what do they do
Cell walls
They protect the cell, provide structure, and prevent bursting in a hypotonic environment
What are eukaryotic cell walls made of
Cellulose or chitin
What do bacterial walls contain
Peptidoglycan
What is peptidoglycan
A network of sugar polymers cross-linked by polypeptides
What components make up archaean cell walls
Polysaccharides and proteins
What do archaean cell walls lack
Peptidoglycan
What is a common way of classifying bacterial species
Gram-staining
What component if prokaryotic cells does gram-staining use
Cell wall composition
What are characteristics of gram-negative bacteria
Less peptidoglycan
Toxic coatings
Antibiotic resistant
What are characteristics of gram-positive bacteria
Cell walls have about 90% peptidoglycan within them
Less toxic
Not antibiotic resistant
Gram pos + neg slide diagram
Diggy
What protective feature do some prokaryotes have
A protective capsule
What do fimbrae do
Allow cells to stick to substrate or other cells
Do prokaryotic cells have fimbrae
Some do
Describe sex pili and what they do
They are longer than Fimbrae and allow for DNA exchange
What are flagella used for
Movement
4 outer characteristics of prokaryotes
Fimbrae
Sex pili
Flagella
Capsule
What do prokaryotic cells lack
Complex compartmentalization
What do specialized membranes do for prokaryotic cells
They perform metabolic functions
Which genome has more DNA
Eukaryotic genome
Which genome has less DNA
Prokaryotic genome
Where is genetic material located in prokaryotes
In the nucleoid of the cell
What does the prokaryotic genome consist of
A circular chromosome
What kind of smaller rings of DNA do some bacteria have
Plasmids
How often do prokaryotes reproduce
Every 1-3 hours
How do prokaryotes reproduce
By binary fission
Are prokaryotic offspring genetically identical
Yes
Are mutation rates high or low during binary fission
Low
What can cause mutations to still arise at fast rates
Rapid reproduction
How many e.coli can be produced in a day in a human host
9 million
What allows for rapid evolution
High diversity from mutations
What is conjunction
A process in which plasmid DNA is transferred directly between cells through direct contact
What structure is used during conjunction
Sex pili
What is transformation
When a bacteria collects DNA from broken down organisms and incorporates it into its own genome
What is transduction
It is the process of bacteria swapping genes through a viral vector
Who obtains energy from light
Phototrophs
Chemotrophs
Obtain energy from chemicals
What do autotrophs require
The require CO2 as a carbon source
What do heterotrophs require
Organic nutrients to make an organic compound
What are the four major modes of nutrition
Chemoautotroph
Chemoheterotroph
Photoautotroph
Photoheterotroph
Who uses chemoautotrophy
Some bacteria and archaea
Who uses chemoheterotrophy
Some bacteria and archaea as well as fungi, animals, and some plants
Who are photoautrotrophs
Bacteria, protists, and most plants
Who are photoheterotrophs
Some bacteria
What does cooperation allow prokaryotes to do
Use environmental resources they could not use as individual cells
What is Nostoc
A cyanobacteria
What organism is a close relative to Nostoc
Anabaena
What are heterocytes?
A specialized thick walled cell used for nitrogen fixation
How does Anabaena exchange metabolic products (nitrogens for sugars)
They use photosynthetic cells and nitrogen fixing cells
How long ago did cyanobacteria start aggregating
3.5 billion years ago
What did early systemisists base prokaryotic taxonomy on and until what time?
They based it on phenotypic criteria until the late 20th century
What has changed how we perceive prokaryotic phyloigeny
Applying molecular systemics to the previous ideas
What has the new system of taxonomy allowed systematists to do
Identify major new clades
5 types of bacteria in the domain Bacteria
Proteobacteria Cyanobacteria Gram-Positive Bacteria Spirochetes Chlamydias
4 types of archaea in the domain Archaea
Euryachaeota
Crenarchaeota
Korarcheota
Lokiarchaeota
1 type of eukaryote in the domain Eukarya
Eukaryotes
What ancestor do all the domains trace back to
LUCA
What are archaea that live in extreme environments called
Extremophiles
What archaea live in highly saline environments
Extreme halophiles
What archaea live in very hot environments
Extreme thermophiles
What arechaes live in swamps and marshes
Methanogens
What do methanogens produce as a waste product
Methane
What kind of respiration do methanogens use
They are strict anaerobes, poisoned by oxygen
What has revealed many new groups of Archaea and Bacteria in recent years
Genetic prospecting
Was do new findings in the prokaryotes provide
They provide more clues to the early evolution of life on Earth
What domain makes up most prokaryotes
Bacteria
Do bacteria use one or many nutritional types
The major groups use many diverse nutritional types
What ways do bacteria get nutrients
Converting atmospheric nitrogen in host tissues to construct proteins
Be pathogenic and/or parasitic
Produce oxygen through photosynthesis
Decompose soil organics
What is a major role of prokaryotes
Recycling nutrients between living and nonliving systems
What form do may prokaryotes appear in
As films or aggregations
What do nitrogen-fixing prokaryotes do for the environment
They add usable nitrogen to the environment
What prokaryotes function as decomposers
Chemoheterotrophic prokaryotes
What do chemoheterotrophic prokaryotes do
Break down corpses, vegetation, and wast products in a systematic way that appears predictable
