Ch. 20 - Biology

chemoautotroph

chemical self-feeder

pathogen

disease causing agents

capsid

protein coat surrounding a virus

the domain archaea corresponds to the kingdom...?

Archaebacteria

the domain bacteria corresponds to the kingdom...?

Eubacteria

retroviruses

a group of RNA viruses when the genetic information of a retrovirus is copied from RNA to DNA instead of DNA to RNA.

vaccine

a preparation of weakened or killed pathogens or inactivated toxins; when injected, it prompts the body produce immunity to a specific disease.

endospore

a thick internal wall that encloses the DNA and a portion of the cytoplasm; can remain dormant for months or age

nitrogen fixers

all organisms need nitrogen to make proteins and other molecules. convert nitrogen into useful forms

how are prokaryotes classified?

as bacteria or archaea — two of the three domains of life

antibiotics

attack a bacterial infection by blocking the growth and reproduction of bacteria; also interrupting proteins or cell processes that are specific to bacterial cells

how do bacteria cause disease?

bacteria causes disease by destroying living cells or by releasing chemicals that upset homeostasis.

prophage

bacteriophage DNA that becomes embedded in the bacterial host's DNA

why do most viruses only infect a specific kind of cell?

because viruses must bind precisely to proteins on the host cell surface and then use the hosts genetic system

how do you treat viral diseases?

cannot be treated with antibiotics; scientists have been working on antiviral drugs that attack specific viral enzymes that host cells do not have

describe nitrogen fixation

converts nitrogen gas into ammonia, which could be converted into nitrates so plants can use it or attached to amino acids that all organisms can use

who was Wendell Stanley?

crystallized the tiny particles to see if they were alive, and were proven to be nonliving

what are the two disease mechanisms?

damaging host tissue and releasing toxins

what are the three roles of prokaryotes in the environment?

decomposers, producers, nitrogen fixers

who was Dmitri Ivanovski?

demonstrated the cause of this particular plat disease— called tobacco mosaic disease— was found in the liquid extract from infected plants, but couldn't identify the culprit

anaerobe

doesn't require oxygen

what is similar between Archaea and Bacteria?

equally small, lack nuclei, and have cell walls.

decomposers

essential in maintaining equilibrium in the environment and are essential to industrial sewage treatment, helping to produce purified water and chemicals that can be used as fertilizers

releasing toxins

ex: diphtheria.

damaging host tissue

ex: tuberculosis. this pathogen is inhaled through the lungs where is can destroy large areas of tissue

what happens after a virus infects a cell?

inside living cells, viruses use their genetic information to make multiple copies of themselves. some viruses replicate immediately, while others initially persist in an inactive state within the host.

describe the domain Bacteria

largest of the two domains; live almost everywhere: fresh water, salt water, land and on and within the bodies of humans and other eukaryotes; cell walls contain peptidoglycan that surrounds the cell membrane and protests the cell from injury; some have flagella

photoheterotrophs

light and other feeder

photoautograph

light self feeder

what are the two patterns of infections?

lytic infections and lysogenic infections

how do you prevent viral diseases?

mostly by prevention which would be to get vaccines and to practice personal hygiene

why are nitrogen fixing bacteria so important?

nitrogen is essential to all living things. however, organisms cannot take in the nitrogen that makes up nearly 80% of the atmosphere. so, nitrogen fixing bacteria convert the nitrogen to ammonia, and then ammonia to nitrates so plants could use it, or attached to amino acids so all organisms can use it

virus

nonliving particle made up of nucleic acids, proteins, and sometimes lipids

mutations

one way prokaryotes evolve; changes in the DNA sequence

how do viruses reproduce?

only reproduce by infecting living cells

heterotroph

other feeder

producers

photosynthetic prokaryotes are among the most important producers on the planet.food chains everywhere are dependent upon prokaryotes as producers of food and biomass.

what are the five ways to control bacteria?

physical removal, sterilization by Heat, food processing, food storage, and disinfectants

conjugation

process where genetic material exchange; a hollow bridge forms between two bacterial cells, and genetic material moves form one cell to the other

what roles do prokaryotes play in the living world?

prokaryotes are essential in maintaining every aspect of the ecological balance of the living world. in addition, some species have specific uses in human industry

how do prokaryotes vary in function and structure?

prokaryotes vary in their size and shape, in the way they move, and in the way they obtain and release energy

aerobe

requires oxygen

bacilli

rod-shaped prokaryotes

in what way do prokaryotes move?

some dont move at all while others are propelled by their flagella

how do viruses differ?

some have an additional membrane that surrounds the capsid; simple viruses contain only a few genes while complex viruses contain hundreds of genes

cocci

spherical prokaryotes

spirilla

spiral prokaryotes

who was Martinus Beijerinck?

suggested that tiny particles the juice caused the disease, and named these tiny particles viruses.

what are two RNA viruses?

the common cold and HIV

describe prokaryotes

the lack a nucleus; unicellular; have DNA located in the cytoplasm

describe the pattern of lysogenic infections

the virus injects DNA into the bacterium. the viral DNA inserts itself in the bacterial chromosome, where it is called a prophage. the prophage may replicate with the bacterium for many generations. the prophage can exit the bacterial chromosome and enter a lytic cycle.the bacterium makes new viral proteins and nucleic acids. the proteins and nucleic acids assemble into new viruses.viral enzymes burst the bacterium's cell wall. the new viruses escape and infect other bacterial cells.

describe the pattern of lytic infections

the virus injects DNA into the bacterium. then the viral genes are transcribed by the host cell. the bacterium makes new viral proteins and nucleic acids. the proteins and nucleic acids assemble into new viruses.viral enzymes burst the bacterium's cell wall. the new viruses escape and infect other bacterial cells.

where do prokaryotes get their energy from?

they store in the form of fuel molecules such as sugars; energy is released from these molecules during fermentation, cellular respiration, or both.

prokaryotes

unicellular organisms that lack a nucleus

how do viruses cause disease?

viruses cause disease by directly destroying living cells or by affecting cellular processes in ways that upset homeostasis.

how does a virus enter a host cell?

viruses have proteins on their surface or capsid that bind to receptor proteins on the cell. the proteins "trick" the cell to take in the virus on in some cases just its genetic material. once inside, viral genes are expressed and destroy the cell

bacteriophages

viruses that infect bacteria

describe the domain Archaea

walls lack peptidoglycan and other lipids; DNA sequence resembles more of a eukaryote than bacteria; live in extremely harsh environments such as thick mud and digestive track of animals; also live in very salty areas like the Great Lakes or hot springs.

lysogenic infection

when a host cell is not immediately taken over. Instead the viral nucleic acid is inserted into the hosts DNA, where it is copied along with the host DNA without damaging the host.

binary fission

when a prokaryote has grown so that it nearly has doubled in size, it replicates its DNA and split in creating two identical cells

lytic infection

when a virus enters a bacterial cell, makes copies of itself, and causes the cell to burst.

what are some human uses of prokaryotes?

yogurt is produced by a bacteria; some bacteria can digest petroleum and remove human-made waste products and poisons from water; others used to synthesize drugs and chemicals through genetic engineering