Free Radicals

Question 1

what is a free radical?

Answer 1

a highly reactive molecule with 1 or more unpaired electrons

Question 2

what are 3 reason why free radicals are so damaging ?

Answer 2

1. all marcomolecules (DNA , proteins , lipids ) are at risk
2. production of other free radicals
3. mutations of DNA and cross links

Question 3

what are 3 ways free radicals are formed ?

Answer 3

1. oxidation
2. radiation
3. toxins

Question 4

what is ROS and where is it formed

Answer 4

its its reactive oxygen species and it is formed in the mitochondria

Question 5

what are the 3 most common ROS formed?

Answer 5

1. Superoxide radical
2. hydrogen peroxide - not free radical but can be
3. hydroxyl radical

Question 6

how much o2 become free radical in the mitochondrion ?

Answer 6

4% of o2 at the end of mitochondria etc becomes free radicals when young but the number increases with age

Question 7

what are 5 free radicals effects on DNA?

Answer 7

1. nucleotide substitutions
   2.cross links
   3.mutation
2. cancer
3. impacts on breast tissue

Question 8

what are free radicals effects on proteins and example

Answer 8

oxidizing protein to lose function and alter confirmation , thiol groups S to C shape

Question 9

with proteins and free radical what happen with age increase

Answer 9

an increase age there is a 2-3 fold in oxidized proteins and increase in cross linked proteins

Question 10

what are free radicals effects on lipids ?

Answer 10

oxidation of lipid or formation of carbonyl group that increase lipid peroxidation that cause a chain reaction in lipid membranes

Question 11

what are 3 evidences of free radical damage and aging

Answer 11

1. experiment animals show oxidative damage to proteins dna , lipids with age
2. hight metabolic rate more FR that shortens life spans
3. organisms that has antioxidant defences increased artificially lived longer

Question 12

how can free radical damage be linked to heart disease ?

Answer 12

oxidized lipids promote thickning of arteries and LDL

Question 13

what are 2 types of endogenous antioxidants ?

Answer 13

1. SOD= superoxide dismutase
2. catalase

Question 14

what does SOD do?

Answer 14

its found in all cells and removes superoxide radicals

Question 15

what is the proof on how does SOD coorerlate to Life span

Answer 15

in drosphilia a decrease in SOD expression, is a decrease in life span 60 -10 days and vice versa increase expression of SOD increased life span 90 days

Question 16

what does catalase do ?

Answer 16

it further breaks down h2o2 from SOD into water

Question 17

what is the most potent antioxidant ?

Answer 17

vitamin E

Question 18

what are the 5 function of vitamin E?

Answer 18

1. lipid soluble
2. protects lipid membranes from free radicals
3. stops lipid damage
   4 .prevents oxidation of LDL cholesterol
4. neutralizes free radicals

Question 19

what are the 4 benefits of vitamin e studies show ?

Answer 19

1. more o2 efficiency in brain heart and organs
2. more stimulation of immune system
3. protection against cancer
4. prevents atherosclerisis

Question 20

what are function of vitamin C?

Answer 20

a reducing agents that inhibits LDL oxidation and decrease risk of cancer and catracts and helps the immune system

Question 21

what is B carotene( carotenoid) ?

Answer 21

precurser of vitamin a and used chemoprevention of cancer

Question 22

what can alot of long term intake of carotenoids do ?

Answer 22

it can lead to chronic disease, heart disease and cancer bc of lon g term tissie damage