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Flashcards in ch 28 Deck (18):
1

Prokaryotes

bacteria, archaea

2

Eukaryotes

eukarya

3

Archaea and eukarya are mose closely related than archaea and bacteria

tru

4

Archaea

-Prokaryotes
-no nucleus
-no membrane bound organelles
0.1-15 um in size (small)
-genome is a single, closed circular DNA molecule

5

3 types of archaea

-halophiles : salty, dead sea, great salt lake

-Thermoacidophiles: hot, acidic, aquatic; yellowstone national park geisers, underwater volcanos

-Methanogens: chemoautotrophs that use CO2 and hydrogen as energy sources, produce methane, anaerobic envoeirnment like swamps and intestines

6

Bacteria

-most common prokaryotic (11,000 species)
-.2-10um in size (bigger than archaea )
-purple: positive, thic peptidoglycan
-pink: negative, little to no peptidoglycan
-Flagella for locomotion
-reproduce by binary fission (no sexual reproduction)
-Endospores: harsh conditions
-single circular chromosomes

7

3 shapes of bacteria

-rod (bacillus)
-spherical (coccus)
-Spiral (spirillus)

8

Types of gene transfer in bacteria (3)

1. conjunction: sex pilus
2. Transformation: dead bacteria
3. Transduction: viruses

9

Bacteria metabolism

1. heterotrophs: requiring ORGANIC carbon for food
2. Chemoautotrophs: use INORGANIC chemicals to make the organic forms
3. Photoautorophs: have chlorophyll and do photosynthesis that releases oxygen (cyanobacteria)

10

Strepetococcus

-pharyngitic: strep throat
-Impetigo infants: mild skin disease
-scarlet fever
-theumatic fever

11

food poisoning

-Clostridium Botulinum: produces toxins in food
-Salmonella: causes infection in the intestines

12

Staphylococcus aureus and MRSA

-about 20% of people are carriers
-usually limited to skin infection

-a strain resistant to methicillin is called MSRA
-kills young, otherwise healthy individuals
-has genes for toxins not found in other S. aureus strains

13

Antibiotics

1. Inhibit protein synthesis by bacteria (Erythomycin and tetracyclines)
2. Inhibit cell wall biosynthesis ( penicillin and cephalosporins)

14

Issues w antibiotics

-killing normal flora (beneficial bacteria)
-bacterial resistance
-potential fatal allergic reaction

15

viruses

-Obligate Parasite: acellular structures that require a living cell to reproduce
-use the host cell's replication machinery, such as ribosomes and certain enzymes
-smaller than bacteria (.03-.2um)

2 main components:

-Capsid (out portion composed of proteins)
-may be surrounded by a lipid envelope
-may have spikes for attachment to a host cell

-Nucleic Acid Cores (DNA or RNA)
-both DNA and RNA may be single or double stranded

16

Viral reproduction

1. attach
2.enter
3.replicate
4. biosynthesis
5. assembly
6. budding

17

Antigenic drift and shift

drift: human influenza virus gets mutated and spikes change?

shift: animal influenza virus and human influenza virus mix; mutant; big

18

Prions

-infectious protein particles
-passed through ingestion of infected tissues
-Scrapie-sheep
-mad cow disease- cow
-chronic wasting disease-deer, elk, moose
-fatal familial insomnia-human
-Creutzfeldt-Jakob's disease-humans