What is the function of the cell wall
Made of peptidoglycan protects and supports each cell
What is the function of the capsule?
To protect the cell and prevent desiccation.
What is the function of the nucleoid?
Where genric information can be found
controls cellular activity.
What is the function od the plasmid?
A small loop of DNA which carries genes that may benefit the survival of an organism.
What is the function of the cytoplasm
Maintains cell shape and stores chemicals needed for metabolic reactions
What is the funtion of mesosomes?
Involved in DNA replication
cell division
excretion of exoenzumes
What is the function of the plasma membrane?
Selectively permeable membrane which regulates the transport of materials in and out of the cell.
What is the function of the flagellum
Helps with movement
Acts as sensory organ-detects temperature and ph changes
What is the function of the pilus?
Helps with adhesion and attachment to other cells or specific surfaces.
How can the two groups of bacteria be distinguished
Through gram staining
Gram positive-purple and gram negative- pink
What are the stages for gram staining
1.dyes peptidoglycan
2.fixes the dye
3.decolourises.
4. counterstain
What dye is used for peptidoglycan? What are the colours produced?
Crystal violet
Colour is purple, both gram-positive and gram-negative
What is used to fix the dye in gram staining? What are the colours produced?
Iodine which keeps it purple-gram-positive and gram-negative
What is used to decolourise the chemical in gram staining? What are the colours produced?
Ethanol
purple results for gram-positive
clear results for gram-negative
What is used for the counterstain in gram staining? What are the colours produced?
safranin
Gram-positive is purple,
gram-negative is pink
Why does gram-negative bacteria appear pink?
Because they have thinner cell walls and lipid membranes that allow ethanol to wash off all the crystal violet purple stain.
