Prokaryotes Flashcards
(12 cards)
What type of cells are bacteria classified as?
Prokaryotes
Bacteria are single-celled organisms without membrane-bound organelles.
What structure in bacteria often contains additional genes for survival?
Plasmids
These genes may include antibiotic resistance or toxin-producing genes.
What is the function of ribosomes in bacteria?
Makes proteins
Ribosomes are essential for protein synthesis.
Where is the nucleoid located in a bacterial cell?
Region where single circular length of DNA is folded
The nucleoid carries all essential genetic information.
What is the composition of the bacterial cell wall?
Peptidoglycan
It is made of long-chained molecules composed of sugar and amino acids.
What is the function of the capsule in bacteria?
Protects cells from drying out and helps cells stick to surfaces
The capsule is a polysaccharide layer outside the cell wall.
How do gram-negative bacteria differ from gram-positive bacteria in terms of gram staining?
Gram-negative bacteria do not retain the gram stain
Their cell wall has an outer layer that prevents retention of the stain.
Why are gram-negative bacteria more resistant to antibiotics?
They have an outer membrane that protects them from antibiotics
This outer membrane is part of their cell wall structure.
What is the typical size range of bacterial cells?
0.5-5 µm
This size range varies among different bacterial species.
What color do gram-positive bacteria stain during a gram stain procedure?
Purple
This is due to their thick peptidoglycan wall absorbing the crystal violet stain.
Fill in the blank: Most meat pathogens are _______.
gram-positive
Gram-positive bacteria are commonly found in meat and are often responsible for foodborne illnesses.
What additional stain is commonly used alongside the gram stain?
Safranin
This stain colors the thin peptidoglycan cell wall red.
