Ch 27: Prokaryotes Flashcards
prokaryote
a single-celled organism whose cell lacks a nucleus and other membrane-bound organelles
plasma membrane
separates what’s inside the
cell from what’s outside of the cell
the barrier between an organism and its environment, made of a phospholipid bilayer and the many different proteins floating around within it
the membrane lets some things through and prevents others, so that the organism can take in food and energy and expel waste
cell wall
a rigid structure around the cell made of peptidoglycan
peptidoglycan
a polymer of sugars and amino acids that creates a mesh-like layer around the cell
cytoplasm
the interior of the cell (generally)
cytosol
the actual a jelly-like fluid substance specifically present within the cytoplasm where all the cellular components float around
nucleoid
the region where the genetic information—a chromosome or set of chromosomes—for a prokaryotic cell can be found
ribosomes
complex macromolecules within the cell—made of RNA and proteins—that perform biological protein synthesis
cell surface area::volume ratio
should be high to maximize exchange with the surroundings while minimizing the volume inside that has to be serviced
this ratio shrinks as cells get bigger
What determines cell size?
metabolic needs
What type of organisms are Archaea and Bacteria?
Prokaryotic, unicellular
How are Archaea related to Eukarya?
More closely related to Eukarya than to Bacteria
What allows Archaea to live in extreme environments?
Unique membrane lipids
Name three types of extremophiles.
- Halophiles
- Acidophiles
- Hyperthermophiles
What is the temperature at which Methanopyrus grows?
98°C
What are the characteristics of Firmicutes?
Diverse Gram-positive bacteria, some produce endospores
What type of bacteria are Chlamydiae?
Obligate intracellular parasites
What is unique about Planctomycetes?
Reproduce by budding, lack peptidoglycan in cell walls
What is the shape of Spirochaetes?
Corkscrew-shaped
What notable feature do Actinobacteria have?
Produce antibiotics and branched filaments
What do Cyanobacteria produce during photosynthesis?
Oxygen
What are the two main types of horizontal gene transfer?
- Transformation
- Conjugation
- Transduction
What is the function of pili in bacteria?
Attachment and conjugation
What is the primary method of asexual reproduction in bacteria?
Binary fission
What is the function of glycocalyx (capsule)?
Protection, evade host defenses, hold colony together
What distinguishes Gram-positive bacteria from Gram-negative bacteria?
Gram-positive have a thick peptidoglycan layer, Gram-negative have a thin layer and outer envelope
What are the five major shapes of bacteria?
- Cocci
- Bacilli
- Vibrios
- Spirochaetes
- Spirilli
What is an akinete?
A dormant structure in cyanobacteria that survives harsh conditions
What are the two main types of autotrophs?
- Photoautotrophs
- Chemoautotrophs
Define obligate aerobes.
Organisms that require oxygen
What role do decomposers play in the ecosystem?
Break down dead organisms to release minerals for reuse
What are Koch’s postulates used for?
To determine if an organism is a pathogen
What is bioremediation?
Use of microbes to reduce harmful materials in the environment
Fill in the blank: ____ are organisms that obtain organic compounds from living hosts.
[Pathogens]
What is biotechnology?
The genetic modification of bacteria genomes to produce desired chemicals.
Biotechnology has wide applications in various industries.
What are some products made using bacteria in the chemical industry?
Products include:
* Enzymes
* Vitamins
* Insulin
* Vaccines
* Antibiotics
Bacteria are grown in large vats for the production of these substances.
What is bioremediation?
The use of microbes to reduce levels of harmful materials in the environment.
This can be applied to wastewater, industrial discharges, and pollution.
True or False: Bacteria are used to make food like yogurt and cheese.
True
Bacteria play a crucial role in the fermentation process for these foods.
Fill in the blank: The use of __________ is to reduce levels of harmful materials in the environment.
[bioremediation]
List some applications of biotechnology in the food industry.
Applications include:
* Production of yogurt
* Production of cheese
These applications rely on the fermentation capabilities of bacteria.
