Bacteria and Viruses Flashcards
Define bacteria.
- A group of single-celled prokaryotic microorganism that has the ability to form spores.
What is the structure of nucleoid in bacteria?
A region containing mostly DNA, along with some RNA & proteins and it is not bounded by a membrane.
Is bacteria a eukaryote or prokaryote?
Prokaryote cell
What is the structure of genophore/circular DNA?
Found in nucleoid; the bacterial “chromosome”; usually circular containing double stranded DNA & most genetic material of organism
What is the function of nucleoid in bacteria?
- Regulates growth
- Reproduction
- Controls bacteria’s activity
What is the function of genophore in bacterial cell?
Contains prokaryotic genetic information.
What is the structure of plasmid in bacteria?
- Small circular DNA containing genes in cytoplasm.
- Seperate from the main DNA of the cell.
- Not associated with protein; reffered to ‘naked’ DNA.
What is the function of Plasmid in bacteria?
- Plasmid contain code that is responsible for antibiotic resistance & other characteristic.
- Plasmid can be transferred between bacteria; from one bacterial species to another.
What is the function of storage granules?
Store nutrients including oxygen, lipids, polyphosphate,or in some cases, sulfur or nitrogen.
What is the structure of ribosome in bacteria?
- Small dot, granular appearance around the cytoplasm.
- Smaller than the ones in eukaryote cell.
Eukaryote ribosome (80S) ; Bacteria ribosome (70S)
What is the function of ribosome in bacteria?
site for messenger RNA translation into proteins or protein synthesis.
What is the structure of cytoplasm in bacteria?
internal “soup” of the cell, jelly-like fluid, mostly water ; does not contain any double membrane-bound organelles
What is the function of cytoplasm in bacteria?
Holds nucleoid, plasmid, ribosomes & storage granule and components necessary for bacterial metabolism and protec them from damage.
What is the stucture of capsule in bacteria?
- Outside the cell wall
- Made out of polysacccharide.
What is the structure of store granule in bacteria?
simple small organelles, bounded by a lipid bilayer membrane.
What is the function of capsule in bacteria?
Protect the cell and act as a barrier against phagocytosis by white blood cell which result in bacterial survival.
What stain can be use to see the capsule in bacteria?
India Ink Stain
What is the structure of cell envelope?
very thin made out of 2 membrane; contains Outer membrane layer, Periplasmic space layer, cell wall, cytoplasmic membrane.
What is the function
Describe the structure outer membrane.
- Can only be seen in Gram-Negative bacteria.
- A phospholipid bilayer that contain lipopolysaccharide.
State the function of outer membrane.
Protect bacteria against harsh enviroment.
What is LPS and it’s function?
lipopolysaccharide; stimulate host’s immune respone.
What is the function of outer membrane proteins?
transmit enviromental signals to the cell, transport materials and act as enzymes.
What is the structure of periplasmic space?
Only found in Gram-Negative bacteria; find in between the outer membrane and the cytoplasmic membrane.
The space contains the cell wall
What is the structure of cell wall in bacteria?
Composed of peptidoglycan
What is the function of cell wall in bacteria?
Maintains cell’s shape & can stimulate a host immune respones
In Gram-Positive, cell wall fully stains blue with crystal violet.
In Gram-Negative, Outer membrane prevents the crystal violet from stainingthe inner cell wall that make the stain.
