Prokaryotes: Bacteria & Archaea Flashcards
Prokaryotes thrive almost everywhere:
- ——: can live in very high salinities
- ——: can survive 3 million rads of radiation (3,000 x human fatal dose)
- ——: can live at temperatures as high as 80° C (176° F)
- ——: can grow at pH 0.03 (acidic enough to dissolve metal)
- Halobacterium Species
- Deinococcus Radiodurans
- Thermus Aquaticus
- Picrophilus Oshimae:
Prokaryotes are most —, and likely the —, orgnaisms on earth
- Abundant
2. First
Prokaryotes are divided into what 2 domains?
- Bacteria
2. Archaea
We actually have more — cells than our — cells
- Bacterial
2. Own
Because bacteria are so much smaller, only comprise about —% of our body weight
0.3%
Common features among all cells:
- ——
- —
- ————
- —
- Plasma Membrane
- Cytoplasm
- Double-stranded DNA Genome
- Ribosomes
Cell Wall:
- — have peptidoglycan
- — lack peptidoglycan
- Bacteria
2. Archaea
DNA replication:
- Both have single origin of —
- Archaeal DNA replication is more similar to that of —
- Replication
2. Eukaryotes
Gene Expression:
*Archaeal — and — are more similar to those of eukaryotes
- Transcription
2. Translation
Autotrophs – carbon from inorganic CO2
- —: energy from Sun
- —: energy from oxidizing inorganic substances (e.g., H2S, NH3 or Fe2+)
- Photoautotrophs
2. Chemolithoautotrophs
Heterotrophs – from organic molecules:
*—: light as energy source but obtain organic carbon made by other organisms
*—: both carbon atoms and energy from organic molecules
Humans are another example
- Photohetrotrophs
2. Chemoheterotroph
Prokaryotic metabolism varies with respect to O2:
- ——: require O2 for cellular respiration
- ——: poisoned by O2 and use anaerobic respiration/fermentation
*——: use O2 if present, but also carry out anaerobic respiration/fermentation if not
- Obligate Aerobes
- Obligate Anaerobes
- Facultative Anaerobes
Most prokaryotes are:
- —, although some species form colonies
- 0.5–5 µm, much — than eukaryotic cells (10–100 µm
- Unicellular
2. Smaller
Prokaryotic cells have a variety of shapes; 3 most common are:
- —
- —
*—
- Spheres (cocci)
- Rods (bacilli)
- Spirals
An important feature of nearly all prokaryotic cells is their cell wall:
- Maintains ——
- — the cell
- Prevents — in a hypotonic environment
- Cell Shape
- Protects
- Bursting
Eukaryotes (plants and fungi): made of — or —
- Cellulose
2. Chitin
Prokaryotes:
- Bacteria: contain —, a network of sugar polymers cross-linked by polypeptides
- Archaea: contain — & — but lack peptidoglycan
- Peptidoglycan
2. Polysaccharides & Proteins
Used to classify bacteria by cell wall composition
- ———: have less peptidoglycan and an outer membrane that can have toxic lipopolysaccharides
- ———: have simpler cell walls with a large amount of peptidoglycan
- Gram-negative bacteria
2. Gram-positive bacteria
Gram-negative bacteria:
- —— of — in cell walls are toxic, causing fever or shock
- Tend to be more —— because outer membrane impedes drug entry
- Lipid portions of lipolysaccharides (LPS)
2. Antibiotic resistant
Gram-positive bacteria:
- Some are — and — to one or more antibiotics
- Many antibiotics (e.g., penicillin) target — and damage bacterial ——
- Virulent & Resistant
2. Cell walls
Capsule: —— or —— that covers some prokaryotes
*Allows adherence to the —, or other individuals, and can shield pathogenic bacteria from the host immune system
- Sticky polysaccharide
- Protein layer
- Substrate
—: extensions of some prokaryotes that help them stick to their substrate or other individuals in a colony
Fimbriae
—: longer than fimbriae and allow prokaryotes to exchange DNA
Pili
Most motile bacteria propel themselves by —
- Scattered about the surface or concentrated at one or both ends
- — of bacteria, archaea, and eukaryotes perform similar functions, but are composed of different proteins and likely evolved independently
- Flagella
2. Flagella
