Antioxidant Defense System and Redox Homeostasis

Question 1

Redox homeostasis

Answer 1

maintain a balance between pro-oxidants and antioxidants

Question 2

Pro-oxidants

Answer 2

free radicals
unstable
build up causes damage

Question 3

Antioxidant

Answer 3

maintain pro-oxidant, prevent damage

don’t want to totally eliminate

Question 4

What is ROS and their importance

Answer 4

reaction oxygen species

- signalling molecules for defence pathway

Question 5

Food constituents that contribute to redox homeostasis

Answer 5

Vitamins = C and E are electron donors stabilise free radicals
Minerals = Zn, Cu, Mn, Se are cofactord and antioxident enzymes
Phytochemicals = electron donors, ACTIVATION of NRF2 carotenoids, flavonoids
transcription factor producing and activating antioxidant genes.

Question 6

2 systems of antioxidant defence

Answer 6

Enzymatic system = involves enzymes and gene products SODS 1-3, glutathione peroxidase, catalase and hemoxygenase.

NON- enzymatic system = plasma and food constituants
albumin = electron donor
Vitamins, Mins and phyotchemicals

Question 7

Antioxidant defence and how it works

Answer 7

1. free radical due to oxygen metabolism
   (Product unstable or ROS has unpaired electrons)
2. form a biological molecule
3. chain reaction = damage to DNA, cell membranes, protein.