ROS

Question 1

What ROS species are there?

Answer 1

HO• (Hydroxyde radical)
H2O2 (Hydrogen peroxide)
O2- (Superoxide)

and others

Question 2

Where do they (ROS) come from?

Answer 2

• respiratory chain => goal: reduce oxygen to water, but uncoupling can generate ROS
• Imbalance in Iron homeostasis
• Xenobiotics/Environmental Pollutants

Question 3

What are functions of ROS in organisms?

Answer 3

• white blood cells/ neutrophils kill bacteria
• signaling
• extensive damage of DNA, Proteins and Lipids

Question 4

Which enzymes destroy reactive oxygen species?

Answer 4

Katalase
Peroxidase
Superoxiddismutase
Superoxidreduktase

Question 5

Katalase (häufigste Rkt in aeroben Bakterien)

Answer 5

2 H2O2 -> 2H2O + O2

Question 6

Peroxidase

Answer 6

H2O2 + NADH + H+ -> 2H2O + NAD+

Question 7

Superoxiddismutase

Answer 7

2O2- + 2H+ -> H2O2 + O2

Question 8

Kombination Superoxiddismutase & Katalase

Answer 8

4O2- + 4H+ -> 2H2O + O2

Question 9

Superoxidreduktase

Answer 9

O2- + 2H+ cyt c (reduziert) -> H2O2 + cyt c (oxidiert)