Microbiology

Question 1

Cell wall function in bacteria

Answer 1

Made of murein (peptide and polysaccharide polymer - peptidogylcan). Prevents lysis under osmotic pressure and protects from damage

Question 2

cell membrane function in bacteria

Answer 2

Selectively permeable, controlling the entry and exit of chemicals to the cell

Question 3

Capsule function in bacteria

Answer 3

This is composed of mucilaginous slime (sugars and water). It prevents dessication, water proofs the cell and allows it to stick to its host. It also protects the bacterium from other cells.

Question 4

70s ribosome functions in bacteria

Answer 4

Synthesises proteins

Question 5

Storage granules function in bacteria

Answer 5

Act as food reserves

Question 6

Circular loop of DNA function in bacteria

Answer 6

Small circular pieces of DNA. These reproduce independently and consist of a handful of genes that may confer antibiotic resistance to the bacterium

Question 7

Plasmid function in bacteria

Answer 7

Possesses genetic information to control bacterial cell activities and allow for bacterial replication

Question 8

Flagellum function in bacteria

Answer 8

Used to propel the cell through fluids

Question 9

Name the ways bacteria can vary

Answer 9

Size
Shape
Cell wall structure (hence staining properties)
Genetic difference
Different metabolic features
Different surface molecules

Question 10

What are the two main ways we can clasify bacteria quickly

Answer 10

By shape
By gram stain reaction

Question 11

What are the three main shapes

Answer 11

Rod shaped (bacillus)
Spherical (coccus)
Spiral (spirillum)

Question 12

What are the differences between the gram-positive and gram-negative bacteria

Answer 12

Negative- thin peptigoglycon walls
Outer lipopolysaccharride membrane

Positive- thick peptigoglycon walls
No outer lipopolysaccharride membrane