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60 Cards in this Set

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Lytic Cycle
viral components synthesized, assembled, and released. Cell dies as a result
•Bacteria,
Vibrio cholerae, changes from nonvirulant to virulent when infected with a virus –Produces toxin that causes cholera
•Lysogenic Cycle
Virus infects bacteria and viral DNA integrates with bacterial DNA.
•Retroviruses are
RNA, animal viruses. They contain a special enzyme (Reverse transcriptase) which allows the genetic code of RNA to be copied (transcribed) to DNA. IU

•DNA is

then used to produce more viruses, as described earlier. •

HIV

•1. Retrovirusattaches to host cell.•2. Virus enters cell•3. Reversetranscription occurs•4. Host cell producesviral components (Biosynthesis)•5. Virus matures•6. New viruses arereleased••Cells do not die , lysogenic (latent) phase - canlast for years•Virus ruptures cellkilling it - leads to AIDS

•AIDS –

Acquired Immunodeficiency Syndrome (HIV) –Formerly infected only apes/monkeys –Mutation occurred allowing HIV to “jump” species –First reported in 1981

•SARS

(severe acute respiratory syndrome) – outbreak in 2003, carried from SE Asia to Toronto, Canada

•West Nile encephalitis

– brought into US, infecting bird & mosquito poplulations

•Hantavirus

– 1993 outbreak, traced to deer mouse, transmitted to humans through fecal contamination Southwest US

•Ebola

– severe hemorrhaging & death (50-90% untreated). Outbreak confined to Africa

•Chicken pox

– spread through contact of infected person, vaccine 1995

•Smallpox

– last case 1977, vaccination wiped out

•Measles

– vaccine available, extremely contagious

•Influenza

– major killer – 1918, 44 million died

•Mononucleosis

– Epstein-Barr virus, spread by infected saliva

•Polio

– Infects CNS & leads to paralysis, often fatal. Vaccine has almost wiped it out

•Viruseslinked to causing cancer (15% viral cause)

•Hepatitis B – liver cancer; •Human papillomavirus (HPV) – cervical cancer

•Prions

infectious protein particle –Smaller than a virus – rogue protein –Prions interact with normal proteins in the body & cause them to change shape

–Discovered: primitive tribe in Papua New Guinea that would eatdeceased person’s brain & developed disease kuru – fatal neurodegenerative disorder

.

•Thermoacidophiles –

found hot springs thermal vents, volcanoes (hot/acidic)

•Extremophiles –

–Methanogen – anaerobic environments •Use H2 to reduce CO2 to methane

–Halophiles

– salt loving Found Great Salt Lake & Dead Sea

EubacteriaDomain:

Bacteria •“true bacteria” •Most of the bacteria today •More common type of prokaryote

•Prokaryotic•

Possess: •single circular chromosome (located in the nucleoid) •No organelles (except ribosomes) •phospholipid bilayer (Cell Membrane) cell wall

–Peptidoglycan

Polysaccharide cross-linked peptide chains

•Flagella-tail

like filament that allows bacteria to move

Thylakoid

Photosynthetic structure YIU

Conjugation pilus (sex pilus)

- allows bacteria to share DNA (often plasmids)

Fimbrae

bristle structures that allow bacteria to attach to surfaces

•Obligate Anaerobes

unable to grow in the presence of oxygen (botulism, gas gangrene & tetanus)

•Facultative anaerobes

– grow in presence or absence of oxygen D

•Aerobic

– require oxygen (most bacteria)

•Autotrophic

– self feeders –Photoautotrophs (light/photosynthetic) –Chemoautotrophs (chemicals – hydrogen gas, hydrogen sulfide & ammonia)

•Heterotrophic

– Chemoheterotrophs = organic nutrients

Saprotrophs –

breaks down large organic molecules into smaller one that can be absorbed (decomposers)

•Mutualistic:

Bacteria & host benefit. –Nitrogen-fixing bacteria in legumes bacteria in digestive tracts
Commensalistic:
Bacteria benefits, host unharmed (E. coli uses up available O2 in intestines, allowing obligate ananaerobes to live there as well)
•Parasitic:
Host is harmed –Pathogenic / diseases
–Pathogens:
•(1)Produce toxins &/or (2)adhere to surfaces and (3) may invade organs or cells 8H
•Bacillus (pl. bacilli) –
rod shaped –Coccobacilli, Pseudomonas
•Coccus (pl. cocci)
– round / spherical –Staphylococci, Streptococci
•Spirillum (pl. spirilli)
– helical-shaped –Spirillum volutans
•Gram-Positive–
thick peptidoglycan cell wall –purple when stained
•Gram-Negative
–More common –Thinner peptidoglycan cell wall –pink when stained
Cyanobacteria
•Formerly - blue-greenalgae (Gram-negative bacteria)•Photosynthetic•Introduced O2to primitive atmosphere•Some -fix nitrogen• food source foraquatic ecosystems•found - fresh water,soil, moist surfaces, hot springs•In association withfungi, they form lichensthat grow on rocks (symbiotic relationship: Cyanobacteria provides organic nutrients to fungus/Fungus providesinorganic nutrients
•Anthrax
– Bacillus anthracis –Biological agent, flu-like symptoms, not contagious, treat w/ antibiotics
•Botulism
– Clostridium botulinum Caused by improperly canned foods, produces a toxin
•Cholera –
Vibrio cholerae –Found in areas of poor sanitation, digestive tract diseases
•Dental caries –
streptococcus –Caused by strep sticking to teeth, eating sugars, producing acid that rots teeth �UC�
•Leprosy –
Mycobacterium leprae –Called Hansens disease – skin lesions
•Lyme disease –
Borrelia bergdorferi –vector, - deer tick, bulls eye rash, joint pain, lethargy, treat w/ antibiotics
•Peptic ulcers –
Helicobacter pylori –Treat w/ antibiotics ))
•Plague –
Yersinia pestis –Bubonic plague –bite of flea, pneumonic plague – inhaled. Major killer
•Pneumonia –
Streptococcus –Respiratory disease –( Streptococcus also causes sore throat, rheumatic fever) Can be bacterial or viral 4
•Tuberculosis
Mycobacterium tuberculosis –Respiratory infection, contagious, many strains are resistant to our antibiotics .
•Chlamydia –-
“Silent STD” Pelvic Inflamatory Disease (PID) – sterility []
•Gonorrhea-
can lead to PID and sterility
•Syphilis
–appears as blister / sores –End stage results in heart disease, mental deficiency, nerve damage, loss of motor function, and blindnes
Importanceof Bacteria
•Responsible forcreating current atmosphere•Decomposers - carboncycle•Fixation of nitrogen(N2) – nitrogen cycle•Industry –vinegars,yogurts, cheese•Many antibioticsderived from bacteria•Cleanenvironmental pollutants –oil degradingbacteria