Exam 2 Study Guide Flashcards
1
Q
Viruses: Structure & Function
A
- Contain nucleic acid (DNA or RNA) in/is surrounded by a protein coat
- some are enclosed by a membrane
- cannot carry out reproduction or metabolic processes on their own, require a host cell
- packaged genes passed from one cell to the next
- affect a limited variety of host cells called host rang of virus. Virus & host have to fit together like a lock & key
2
Q
Domain Archaea vs. Ddomain Eukarya
A
- Archaea: nuclear envelope is absent. Do not have membrane enclosed organelles. No peptidoglycan. Introns present in some genes.
- Eukarya: nuclear envelope present. Membrane enclosed organelles present. No peptidoglycan. Introns present.
- Archaea are masters of adaptation
3
Q
Halobacterium
A
- Halobacteria: use light to drive synthesis of ATP, extreme halophiles = salt tolerant
- Deinococcus Radiodurans: 3 million rads of radiation
4
Q
Prokaryote Shapes
A
small, unicellular, well organized, spherical, rod, spiral
5
Q
Differences in cell walls between Archaea and bacteria
A
- Bacteria: peptidoglycan made up of sugar polymers that are cross linked by polypeptides
- Archaea: polysaccharids and proteins
6
Q
Differences in cell walls between gram + and gram -
A
- Gram + has larger # of peptidoglycan in cell wall
- Gram - has lipopolysaccharides in outer membrane of cell wall
- more complex - more resistant to antibiotics
7
Q
Prokaryote cell wall structures and functions
A
- some prokaryotes have a capsule on the outside of a cell wall
- sticky & composed of polysaccharides or proteins
- allow prokaryotes to stick to each other or substrates ( from colony)
- protects against dehydration
- offers protection from immune system of a host
- Fimbriae - hairlike projections
- allows prokaryote to stick to substrate, each other to a host
- sex pili: an appendage used to connect 2 prokaryotes prior to transfer of DNA from one cell to the next
8
Q
Transformation, Transduction, Conjugation
A
- Transformation: prokaryotes can take DNA that’s been left in the environment from other prokaryotes and use it in their gene sequence
- Conjugation: genetic material is transferred between bacteria while they are temporarily joined
- transfer is one way
- the ability to form mating bridge or sex pilus is due to the presence of an f-factor gene – located on a plasmid
9
Q
Prokaryote Modes of Nutrition
A
- Autotrophs: used carbon dioxide to make organic compounds
- Heterotophs: need at least 1 organic compound to make organic compounds
10
Q
Role of oxygen & nitrogen in metabolism of prokaryotes
A
- obligate aerobes: must use oxygen for aerobic respiration (oxygen is final electron acceptor)
- obligate anaerobes: oxygen is poisonous, use anaerobic respiration or fermentation (final electron acceptor is nitrate or sulfate ion)
- facultative anaerobe: use aerobic respiration if oxygen is available if its not do anaerobic respiration
- nitrogen essentail for all organisms
- some prokaryotes can do nitrogen fixation
11
Q
Ecological & economic benefits of prokaryotes
A
- angler fish - has relationship with bioluminescent bacteria
- located under eye of fish - attracts prey & mates for the fish
- fish provides nutrients for the bacteria & habitat
- ***mutualistic relationship
- staphylococcus + human
- humans provide habitat & nutrients for the bacterium
- neither harms nor benefits us
- ***commensalism
- TB bacterium + humans
- humans provide habitat & resources
- disease & death
- ***parasitism (1 benefit, 1 harmed)
12
Q
Characteristics of supergroups Excavata, Chromalveolata, Rhizaria, Archaeplastida, Unikonta, & the claeds under them
A
- Excavata: all members have a feeding group on the side of their body (cell)
- Diplomonads & Parabasalids
- Lack plastids
- have modified mitochondria
- Diplomonads
- mitochondria - mitosomes
- use glycolysis only to produce ATP
- Parabasalids
- small mitochondria - hydrogenosomes
- use anaerobic respiration & use hydrogen gas as a byproduct
- Eu
