Exam - Selenium

Question 1

supplement label for selenium

Answer 1

super antioxidant support

Question 2

how do plants incorporate selenium

Answer 2

from the soil into methane and cysteine instead of sulphur

Question 3

what is selenium content in food determine by

Answer 3

selenium levels in soil

Question 4

how are selenoAA absorbed

Answer 4

in small intestine by amino acid transporters and travel freely in blood

Question 5

what form of selenium does the body use

Answer 5

selenocysteine

Question 6

how many selenocysteine containing proteins in the body are involved in thyroid hormone metabolism, DNA synthesis and protection from oxidative damage

Answer 6

30

Question 7

what areas have selenium deficiencies

Answer 7

china and africa

Question 8

disease with selenium deficiency

Answer 8

Keshen disease

Question 9

what is Keshen disease

Answer 9

cardiomyopathy from cell damage by free radicals

Question 10

form of selenium toxicity

Answer 10

selenosis - chronic consumption of lots of Brazil nuts
can lead to hair and nail loss

Question 11

2 important selenoproteins involved in oxidant defence

Answer 11

glutathione peroxidase
fatty acid peroxidase

Question 12

what is the substrate used by glutathione peroxidase and fatty acid peroxidase

Answer 12

glutathione (GSH) - helps protects cells against oxidative damage

Question 13

what is glutathione

Answer 13

the major intracellular reducing agent

Question 14

what kind of electron donor is GSH

Answer 14

single electron donor - 2 GSHs are needed per reaction

Question 15

what happens to GSH when oxidized

Answer 15

it reacts with another GSH to form GSSG

Question 16

what percentages of GSSG and GSH does a healthy cell have

Answer 16

> 90% GSH
<10% GSSG

Question 17

what does GSSG stand for

Answer 17

glutathione disulfide

Question 18

what do high cellular levels of GSSG indicate

Answer 18

high oxidative stress

Question 19

what does the pentose phosphate pathway do

Answer 19

regenerates NADPH