Prokaryotes: pt. 2 Flashcards
What is the bacterial capsule (what is it made of)?
Organized, protective layer made of polysaccharides
What are the functions of bacterial capsules?
- Protects against viruses/ other substances
- Resists immune cell phagocytosis
What are bacterial slime layers?
Unorganized, easily removable protective layer that covers capsule.
What are the functions of the slime layer?
- Protects against environment/antibiotics
- Adhere to smooth surfaces
- What are bacterial glycocalyx?
- Where are they located?
- Polysaccharides that extend from surface of bacterium.
- Extend from both capsule and slime layers.
What is the main function of glycocalyx?
Aid in attachment to solid surfaces.
- What is the S-layer of bacterium?
- Where is it located?
Regular structured layer that attaches directly to:
Peptidoglycan layer (gram positive)
Lipopolysaccharide layer (gram negative)
What are the functions of the s-layer in bacterium?
Protect against ion/pH change,
osmotic pressure,
and other bacteria
Give the names for microbes with:
1) one flagella
2) one flagellum on one end
3) Flagella clusters on one end
4) one flagellum on each end
5) Flagellum cluster on each end
1) monothricous
2) Polar
3) Lopothrocous
4) Amphitrichous
5) Amiphilotrichous
- Flagella movement that moves smoothly through liquid:
- Peritrichous flagella movement in moist surfaces:
- Swimming
- Swarming
Bacterial, jerky movement through use of pili on solid surfaces:
Bacterial smooth movement on solid surfaces:
- Twitching
- Gliding
Bacterial movement by way of chemical attractants and repellants:
Chemotaxis
What are the shorter extensions made of protein that aid in motility, attachment, and conjugation known as:
Pili
What are the bacterial cell structures that:
- contain cell’s chromosomes
- contain genomes
- circular, separated, DNA
- site of protein synthesis
- space for nutrients, enzymes, and gas
- Nucleoid
- Chromosome
- Plasmid
- Ribosomes
- Inclusions
What are the dormant cells that are formed within certain bacterial cells known as?
Endospores
How do endospores aid bacteria?
They are resistant to environmental stress (heat, chemicals)
What is significant about Bacillus botulinum?
What class of bacteria is it?
Its endospores, when grown in the right conditions, create world’s deadliest neurotoxin.
Gram negative
What is significant about Bacillus anthracis?
What class of bacteria are they?
Its endospores (when inhaled or injected) cause exotoxin.
Gram Positive
Why do archaea shaped in a variety of odd ways (branched or flat)?
Increases surface area of the cell.
What are the differences between archaea and bacteria cells in:
a) Plasma membrane
b) Cell wall
a) Different lipids
b) Cell walls don’t have peptidoglycan
What are the cell envelopes of bacterial cells?
The plasma membrane and all layers external to it
What is different about the cell envelopes of archaea?
- Capsule and slime layers not present
- S-layer is major component
- Can be monolayers (not just bilayers)
- How are hydrocarbons attached differently in archaea?
- How does this help?
- Attached by Ether links
Bacteria are attached by ester links
- More resistant to chemical attack and heat
What are the two major lipid components in archaea?
1) Glycerol diether
2) Diglycerol tetraether
How do the ribosomes of archaea differ from bacteria?
Have more ribosomal proteins
and
antibiotics do not affect archaea
How do the nucleoid of archaea differ?
All chromosomes are circular double stranded DNA (dsDNA)
Coil their chromosomes around histones and nucelosomes (like eukaryotes)
- How do archaea get around?
- What is different compared to bacteria?
- Use pilli for attachment
- Have cannulae, hami, and archaella
What are the cannulae of archaea?
Hollow, tube structures.
Daughter cells are connected by these.
What are the hami of archaea?
Tiny hooks that extend from cell.
What are the arcahella of archaea?
Flagella like structures
What are the average sizes of ribosomes for both bacteria and archaea?
70s
How do the plasmids of archaea and bacteria differ?
Bacteria have both circular linear dsDNA
Archaea have only circular
