Chapter 25- Bacteria and Archaea

Mutualism

A symbiotic relationship in which both partners benefit

Phototrophs

Capture energy from light

Obligate anaerobes

Carry on anaerobic respiration; they respire with terminal electron acceptors other than oxygen, such as sulfate, iron, or nitrate

Most prokaryotes have a ______ surrounding the plasma membrane and provides a rigid framework that supports the cell and helps it maintain shape

Cell wall

Chemoheterotrophs

Depend on organic molecules for both carbon and energy sources; most are free-living decomposers that obtain carbon/energy from dead organic matter

What bacterial process is involved in the production of cheese and yogurt?

Fermentation

Transformation

When a prokaryotic cell takes up foreign DNA

Commensalism

A symbiotic relationship where one partner benefits and the other is neither harmed nor benefited

How do some bacteria respond to adverse environmental conditions?

Bacteria form endospores

What prokaryote method of reproduction does not result in genetic variation?

Binary fission

Gram-positive bacteria

Cell walls are very thick and consist primarily of peptidoglycan; absorbs and retains crystal violet stain in lab

What are the different shapes of prokaryotes?

Cocci (round), bacilli (rod-shaped), spirochete (spiral, flexible), spirillum (spiral, rigid), vibrio (spirillum shaped like a comma)

Heterotrophs

Obtain carbon atoms from the organic compounds of other organisms

What is missing in the cell walls of archaea but not bacteria?

Peptidoglycan

How do prokaryotes benefit us?

They inhabit soil, produce antibiotics, are used in bioremediation (process of using microorganisms to detoxify/remove oil, gas, and other pollutants/ toxic chemicals from the environment)

Horizontal gene transfer

When an organism (or virus) transfers genetic material to another organism that is not its offspring

A bacterium that uses the oxidation of inorganic compounds to provide energy for manufacturing nutritious organic compounds is a

chemoautotroph

What are spherical shaped bacteria called?

cocci

Prokaryotic cells do/don't have a nucleus or other membrane-bound organelles

Don't

Photoheterotrophs

Obtain their carbon from other organisms but use chlorophyll and other photosynthetic pigments to capture energy from sunlight

What are the 5 subgroups of bacteria

Proteobacteria, gram-positive, Cyanobacteria, chlamydias, spirochetes

Plasmids

Smaller circular fragments of DNA

What is the purpose of the sex pili?

To transmit DNA between bacteria

Symbiosis

An intimate relationship between two or more species

How do bacteria move?

By means of a rotating flagella

Binary fission

Equal division of a prokaryotic cell into two (asexual reproduction)

Describe the diverse types of Archaea living in extreme and more moderate environments

Extreme halophiles: salt loving; extreme thermophiles: heat loving; methanogens: live in anaerobic environments, give off methane as a waste product; moderate environments: in the ocean

Sex pili

Important in transmitting DNA between bacteria

Flagellum (flagella) function

Movement

What type of symbiotic relationship occurs between a ruminant and the bacteria in its digestive tract?

Mutualism

Peptidoglycan

Present in bacterial cell wall, absent in archaeology cell wall

Nitrogen fixation

Reduction of nitrogen in the atmosphere to ammonia

Nitrification

The conversion of ammonia to nitrate by certain bacteria in the soil

Although there is no membrane bound nucleus, prokaryotes have a nuclear area called ____

The nucleoid, which contains DNA

Conjugation

Two cells of different mating types come together and genetic material is transferred from one to the other

Fimbrae function

attachment

Endospore

A durable cell produced in stressful environments by the process of binary fission, and will then germinate when conditions are favorable again

Transduction

A phage carries bacterial or archaeal genes from one bacterial or archaeal cell into another

Endotoxins

A poisonous substance in the cell walls of gram-negative bacteria

Exotoxins

A poisonous substance released by certain bacteria

Parasitism

A symbiotic relationship where the parter that benefits lives in/on the partner that is harmed

Biofilm

A community of microorganisms attached to a surface

Bacterial chemoautotrophs use organic chemicals as an energy source (true/false)

False

Chemotrophs

Obtain energy from chemical compounds

Genes for the resistance to antibiotics are usually located _____.

On plasmids

Aerobic

Require oxygen for cellular respiration

Gene transfer

Results in genetic recombination; transformation, transduction, conjugation

What is a chain of round bacteria called?

Streptococci

Capsule

Surrounds cell wall; adds protection against phagocytosis (engulfment from other microorganisms)

Vertical gene transfer

Transfer of genetic material from parent to offspring

Chemoautotrophs

Use carbon dioxide as a carbon source, but do not use sunlight as their energy source; obtain energy by oxidizing inorganic chemical substances

Autotrophs

Use inorganic compounds as a source of carbon for manufacturing their organic molecules

Facultative anaerobes

Use oxygen for cellular respiration if it is available but can carry on metabolism anaerobically when necessary

Photoautotrophs

Use the energy from sunlight to synthesize organic compounds from carbon dioxide and other inorganic compounds

Budding

Asexual reproduction where a cell develops a bulge, or bud, that enlarges, matures, and eventually separates from the mother cell

Fragmentation

Asexual reproduction where walls develop within a cell which then separates into several new cells

The ____ keeps the cell from bursting under hypotonic conditions

Cell wall

Gram-negative bacteria

Cell walls contain 2 layers: a thin peptidoglycan layer and a thick outer membrane (resembling plasma membrane but contains polysaccharides bonded to lipids; does not retain the stain when rinsed with alcohol; antibiotics will not help with infections in this case (cold/flu)