Chapter 26 and 27 Flashcards
Bacteria
One of three taxonomic domains of life
Consists of
unicellular prokaryotes are distinguished by cell walls composed largely of peptidoglycan.
Plasma membranes similar to those of eukaryotic cells, ribosomes
RNA polymerase that differs from those in archaea or eukaryotes
Archaea
One of three taxonomic domains of life
Consists of unicellular prokaryotes distinguished by cell walls made of certain polysaccharides not found in bacterial or eukaryotic cell walls.
Plasma membranes composed of unique phospholipid.
ribosomes and RNA polymerase similar to those of eukaryotes
What are the similarities in all bacteria and archaea
They are all unicellular and prokaryotic (lack membrane bound nucleus)
Eukarya
One of the three taxonomic domains of life, consists of unicellular organisms, multicellular organisms (fungi, plants, animals) distinguished by a membrane-bound nucleus, numerous organelles and a extensive cytoskeleton.
microbiome
community of microbes that naturally inhabits a particular area and encompasses all genetic material contained within it
How is bacteria and archaea different
- Bacteria has one type of RNA polymerase consists of five subunits and archaea has one type that consists of 13 subunits
- Peptidoglycan in cell wall: In bacteria it is present and in archaea it is absent
- First amino acid incorporated during translation: Formylmethionine in bacteria and methionine in archaea
- In bacteria histones are associated in DNA, in archaea it is not
Microbes
Any microscopic organism, including bacteria, archaea, and various tiny eukaryotes
Microbiology
Field of study concerned with microscopic organisms
Extremophiles
An organism that thrives in an “extreme” environment
Pathogens
Bacteria that cause disease. Effects tissues at the body’s entry points
Who confirmed the existence of bacteria and that it links to diseases
Robert Koch
Kosh’s postulates
Four criteria used to determine whether a suspected infectious agent causes a particular disease
Microbes must be present in individuals suffering from the disease and absent in healthy individuals.
The organism must be isolated and grown in a pure culture away from the host organism.
If organisms from pure culture are injected into a healthy experimental animal, the disease symptoms should appear
The organism should be isolated from the diseased experimental animal, and demonstrated by its size, shape, and color to be the same as the original organism
Germ theory of disease
The theory that infectious diseases are caused by bacteria, viruses, and other microbes.
Infectious diseases
Disease caused by viruses, bacteria and fungi
Three ways infectious diseases are spread
Some are passed from person to person
Some are transmitted by bites from insects or animals
Some are acquired by ingesting contaminated food or water or being exposed to microbes in the surrounding environment
Virulence
Ability to cause disease
Heritable trait that varies among individuals in a population
Toxin
Poison produced by a living organism, such as a plant, animal, or microorganism
Endospores
Tough thick-walled dormant structures formed by bacteria during environmental stress
Endospores
Tough thick-walled structures formed during times of environmental stress, often in response to a lack of nutrients.
Antibiotics
Molecules that kill bacteria or stop them from growing.
Biofilms
dense bacterial colonies enmeshed in a polysaccharide-rich matrix that helps shield the bacteria from antibiotics
Enrichment culture
A method of detecting and obtaining cells with specific characteristics by placing a sample, under a specific set of conditions and isolating those cells that grow rapidly in response
Thermophiles
Bacterium or archaean that thrives in very hot environments
Metagenomics (environmental sequencing)
The inventory of all the genes in a community or ecosystem created by sequencing, analyzing, and comparing the genomes of the component organisms.
Direct sequencing
a technique based on isolating and sequencing a specific gene from organisms found in a particular habitat
Lateral gene transfer
The idea that genes move laterally between different species
Binary fission
Cell division used for asexual reproduction of prokaryote cells
Transformation
when bacteria or archaea take up DNA from the environment that has been released by cell lysis or secreted
Transduction
When viruses pick up DNA from one prokaryotic cell and transfer it to another cell
Conjugation
When genetic information is transferred by direct cell-to-cell contact
Steps to plasmid transfer via conjugation
- Two bacterial cells come into contact. One contains plasmid
- Copy of plasmid transferred from donor cell to recipient cell through a conjugation tube
- Recipient cell contains plasmid
Recombination via conjugation
- portion of main chromosomes are copied and transferred through conjugation tube to recipient cell
- Transferred portion of chromosome recombines with chromosome of recipient cell
- Recipient cell contains bacterial chromosome
In what ways are organisms diverse from each other
Size
Shape and arrangement
Motility
Structural differences betwen archaea and bacteria
archaea have unique phospholipids in their plasma membrane, and the bacteria have a unique compound called peptidoglycan in their cell walls
Gram stain
A staining technique used to distinguish two types of cell walls
Gram positive
Describes bacteria that looks purple with a gram stain.
Have cell walls composed out of extensive peptidoglycan and no outer phospholipid layer
Gram negative
Describing bacteria that look pink when treated with a gram stain.
These bacteria have a cell wall composed of a thin layer of peptidoglycan and an outer phospholipid layer
Phototrophs
Use light energy to excite electrons. ATP is produced by photophosphorylation
Chemooganotrophs
Organisms that obtains ATp from oxidation of reduced organic compounds
Autotrophs
Produce its own food from simple starting such as CO2 and methane
Heterotrophs
Organism that eats other plants or animals for energy and nutrients
Chemolithotrophs
Bacteria capable of using inorganic molecules for their fueling reactions
Three ways bacteria and archaea acquire energy to produce ATP
phototrophs
Chemoorganotrophs
Chemolithotrophs
How bacteria and archaea obtain building blocks with carbon-carbon bonds
Autotrophs
Heterotrophs
Fermentation
the process in which a substance breaks down into a simpler substance.
Allows cells to continue making ATP with no electron transport chain
Oxygenic
Referring to any process or reaction that produces oxygen
Photophosphorylation
Production of ATP molecules by ATP synthase using proton motive force generated either
(1) during photosynthesis, as light-excited electrons flow through an electron transport chain
(2) In some bacteria or archaea, as rhodopsin-like molecules absorbed light energy to pump protons across the plasma membrane to create a chemiosmotic gradient
Methanotrophs
Prokaryotes that use methane as their carbon source
Methanogens
Organisms produce methane as a by-product of cellular respiration
Cyanobacteria
A lineage of photosynthetic bacteria formerly known as blue-green algae.
Known to have been the first to evolve photosynthesis
nitrogen fixation
a chemical process that converts atmospheric nitrogen into ammonia, which is absorbed by organisms
nitrogen cycle
biogeochemical process through which nitrogen is converted into many forms, consecutively passing from the atmosphere to the soil to organism and back into the atmosphere
Endosymbionts
Organism that lives in symbiotic relationship inside the body of its host
Fruiting bodies
Structure that forms in some prokaryotics, fungi, and protists for spore dispersal.
Key lineages of bacteria and archaea
Actinobacteria, Chlamidyae, Cyanobacteria, Firmicutes, Proteobacteria, Spirochaetes, Crenarchaeota (Eocytes), Euryarchaeota, and Thaumarchaeota
bioremediation
use of bacteria and archaea to clean polluted sites using two strategies
- Fertilize contaminated sites to encourage the growth of existing bacteria and archaea that degrade toxins
- “Seeding” or adding, specific species of bacteria and archaea to contaminated sites
Nitrogen-based fertilizers
When NH3 added to soil, much is used by bacteria as food, then bacteria release nitrates as water
Anoxic dead zones
Created when nitrates are released into aquatic environments by nitrogen-based fertilizers and goes on to decrease oxygen
Protists
Diverse group that include all eukaryotes except land plants, fungi, and animals
Paraphyletic which means it represents some of the descendants of a common ancestor but not all
No synapmorphies
Common feature of protists
Live in environments where they are surrounded by water
What is malaria and what is it caused by
Chronic health problems caused by 5 species of parasitic protist plasmodium
Bloom
When unicellular species population grows rapidly and reaches high densities in aquatic environment
Dinoflagellates
photosynthetic, toxic protists that cause harmful blooms
Primary producers
Species that produce chemical energy by photosynthesis
Phytoplankton
Photosynthetic plankton which makes half the total CO2 on Earth
Plankton
protists and other small organisms that drift in open oceans or lakes are called plankton
Basis of the food chain
Food chain
Describes nutritional relationships among organisms
Nuclear envelope
Allows greater diversity in eukaryotes by separating transcription and translation
Support and protection for protists
Cell walls, hard external shells, rigid structures inside plasma membrane
Endosymbiosis
When individuals of one species lives inside another for mutual benefit
First eukaryote
Was created by endosymbiosis between 2 prokaryotes (archaea host and bacteria) that allowed for more efficient energy use
Phagocytosis
Process by which certain living cells called phagocytes engulf other cells, particles and even pathogens
Absorptive feeding
Nutrients taken up across plasma membrane, directly from the environment
Decomposers
organisms that feed on dead organic matter
Parasite
Absorptive feeders that live inside organisms and damages them
How protists move
Amoeboid motion
Swimming via flagella or cilia
Amoeboid motion
Sliding movement in some protists by streaming of pseudopodia
How protists reproduce
Asexual reproduction based on mitosis
Sexual reproduction based on meiosis
Life cycle
Describes sequence of events as individuals grow, mature and reproduce
Alternation of generations
means that plants alternate between two different life stages, or generations, in their life cycle;
One phase of cycle based on haploid (n) and another on diploid (2n)
Gametophyte
One multicellular stage of sexual reproduction process that produce haploid gametes
Two gametes fuse to produce diploid zygote
Sporophyte
Multicellular diploid form; produces spores (haploid cells) by meiosis
Spores divide by mitosis to produce haploid gametophyte
Chemoautotrophs
only need carbon dioxide as a carbon source and obtain energy by oxidizing inorganic substances
