Module 5 immunology

Question 1

Describe the structure of bacterial cell walls in gram positive and negative strains

Answer 1

In gram positive bacteria, the peptidoglycan forms a thick layer (20-80nm) external the to the membrane

In gram negative speeches, the peptidoglycan layer is thin (5-10nm) and is overlaid by an outer membrane, anchored to lipoprotein molecules in the peptidoglycan layer.

Question 2

Identify bacterial flagella and their benefits

Answer 2

Flagella are long helical filaments extending from the cell surface, which enable to move in their environment

Question 3

Explain the relevance of oxygen on growth of anaerobes, aerobe and facultative growth

Answer 3

Obligate aerobes need oxygen to survive

Facultative anaerobes can survive with or without oxygen

Obligate Aerobes only survive without the presence of oxygen

Question 4

Summarise the nutrient requirements for bacterial growth, for example special needs for amino acids in media

Answer 4

Water, a source of carbon, a source of nitrogen and some inorganic salts.