Chapter 12- Prokaryotes and Viruses

reproduction in viruses

- viruses must use a host and "hijack" its machinery -virus tells the host cell to begin producing more virus particles -then the virus tells the cell to lyse, or burst open, to flood the surrounding area with new viruses that can infect the new host cells

conjugation

-a plasmid replicates and is transferred from one bacterium to another -uses a pilus (hair like) -one-way transfer

cyanobacteria

-autotrophic -help cycle materials such as nitrogen and carbon through the environment -produce oxygen and are a source of food for many organisms

transformation

-bacteria takes in a free-floating piece of bacterial DNA -trait is then expressed -known to occur in only a few types of bacteria

gram postive

-greater amounts of peptidoglycan -purple

gram negative

-less amounts of peptidoglycan -pink or red

dna forms

-nucleoid -one circular chromosome -plasmids - smaller circular DNA molecules - passed between bacteria during reproduction - some carry antibiotic- resistant genes that allow them to survive

capsules

-protect bacteria from drying out -many have capsules outside their cell walls

transduction

-the transfer of genetic information from one bacterium to another by way of a bacteriophage -a virus that infects bacteria -attaches, empties its genetic contents, viral genes tell the bacterium to make more, new burst out , new attachment , injects new genes

lysogenic cycle

-virus infects, but does not destroy -the cell divides and continues to copy the virus's genetic material -herpes simplex, varicella zoster

viruses

-viruses carry genetic information -viruses are not cells, they infect a host cell to continue activity -viruses are smaller than bacteria

3 parts that resemble cells

1. DNA or RNA; never both 2. capsid -protein coat 3. envelope: lipid bilayer that surrounds the capsids; studded with proteins; made from the cell membrane of the cell that it infects -not found in all viruses

If the prefix staphylo- means "cluster". What would Staphylococcus bacteria look like?

A cluster of spheres

flagellum

A long, whiplike structure that helps a cell to move

How are archaea and bacteria different?

Archaea live in extreme environments; bacteria do not. Bacterial cell walls contain peptidoglycan; archaeal cell walls contain other proteins and isoprene Transcription and translation processes are different in each

Why are there bad bacteria in the world?

Bad bacteria are the result of God's curse on the earth for mankind's sin

How are archaea and bacteria similar?

Both archaea and bacteria are prokaryotes and can act as decomposers

microbiome

The collective genomes of the microorganisms (microbiota) that live in an environmental niche

Which of the following is not a characteristic of archaea?

They are eukaryotic.

Though prokaryotic, archaea share many characteristics with eukaryotes. true or false

True

pathogen

a substance that causes disease

vectors

an organism that is a carrier of pathogens

decomposers

bacteria that get their energy form dead and decaying matter

Which type of bacterial genetic replication involves asexual reproduction and is most common in bacteria?

binary fission

A bacterium can transfer a plasmid to another bacterium during

conjugation

A bacterium's capsule serves mainly as a means of movement. true or false

false

e. coli

fights off pathogens in the gut; but can cause severe diarrhea and dehydration

viroids

infectious particles made of a short, circular strand of RNA -no capsid or envelope -infect only plants

prions

infectious particles made only of abnormal proteins -contain no genetic information -smaller than viroids and tend to infect the brains of animals and people

Archaea that live in the intestines of animals and that produce gas are known as __________

methanogens

probiotics

microbial cultures that can be ingested -help prevent growth

binary fission

nucleoid replicates and then divides producing two identical cells

gene therapy

potential to cure diseases that were once considered incurable

lytic cycle

rapid infection and destruction of a host cell

Which two types of archaea thrive in hot environments?

thermophiles and acidophiles

retroviruses

viruses that can force a cell to transcribe its RNA into the cell's DNA -HIV