End part

Question 1

what are 2 examples of molecular repair proteins?

Answer 1

1. Thiroeredoxin- reductase enzymes, donate electrons to keep things in a reduced phase 2. heat shcok proteins is like the protein police and is involved in all steps of protein syntehsis and recognizes damage to proteins.

Question 2

What does ARE stand for.

what are they?

Answer 2

antioxidant response elements

also knwon as promotor regions on genes

Question 3

what are the first and second major oxidative stressors that can happen?

Answer 3

1. Production of ROS –> oxidative stress
2. Bioactivation of xenobiotics to reactive electrophiles

Question 4

what is an example of an uncoupler

Answer 4

pentachlorophenol (fungicide) it uncouples the gradient and makes it leaky like an ionophore. also dinitrophenois- donates protons to inner mitochondria space. Used by body builders.

Question 5

what is the half life of ozone?

Answer 5

7 minutes

Question 6

what prevents delivery of the electrons to the electron transport chain?

Answer 6

anything that interferes with glycolysis or the kreb cycle

Question 7

why is increased calcium bad?

Answer 7

increased calcium can cause the inside of the cell to become more positive and therefore you dont have a strong electron gradient and therefore you cannot create enough ATP

Question 8

describe nucelotide excision repair

Answer 8

basically this is repair that happens in an epoxide which an aromatic ring with an oxygen that is a super reactice metabolite binds to DNA.

Question 9

what is an example of something that could cause direct damage to the plasma membrane?

Answer 9

solvents (non-polar) in other words they are lipophilic.

Question 10

describe MPT- mitochondrial permeability transition. -

Answer 10

it starts recycling everything basically. Recycles itself and lets neighbor go through mitosis.

Question 11

what are 4 symptoms persay of oxidative damage to DNA?

Answer 11

1. Base oxidation
2. Sugar oxidation
3. Strand break (single/double)
4. DNA-protein crosslinks

Question 12

describe lipid peroxidation

Answer 12

can cause cell membranes to become nonfunctional and can cause cell death. Repair involved vitamins E and C

Question 13

what are 5 ways to impair ATP synthesis?

Answer 13

1. Delivery of the electrons to the electron transport chain. 2. delivery of O2- like carbon monoxide 3. Block function of electron transport chain. 4. Inhibition of ATP synthesis 5. Uncouple the electrochemical gradient

Question 14

what does ROS stand for?

Answer 14

reactive oxygen species

Question 15

How many oxygen molecules does not turn into water but into a superoxide anion radical?

Answer 15

1/100

Question 16

what are the three enzymes involved in nucleotide excision repair?

Answer 16

1. Endonuclease- snips DNA from where the damage occurs. 2. DNA polymerase 3. DNA ligase

Question 17

Draw the step wise reduction of molecular oxygen in biological systems:

Answer 17

Question 18

when all mitochondria die?

Answer 18

the cell goes through necrosis

Question 19

Ionophore:

Answer 19

makes the inner mitochondria membrane leaky

Question 20

Ozone is catalyzed by what?

Answer 20

NO2 or car exhaust

Question 21

what is the major target organ of the paraquat?

Answer 21

the lung. Accumulates in the alveolar cells of the lung.

Question 22

what happens if more than a few mitochondria die

Answer 22

get activations of caspase which is execution enzymes and then the cell will go through apoptosis

Question 23

what inhibits protein synthesis?

Answer 23

ethanol! GSH synthesis. ethanol has the ability to suppress protein synthesis and makes cell susceptible to dyeing.

Question 24

draw out the table of differences between apoptosis and necrosis. 11 differences.

Answer 24

Question 25

what are the toxicity examples resulting from repair failure?

Answer 25

1. necrosis
2. Fibrosis: excessive prodiction of ECM (extracellular matrix)
3. carcinogenesis: development of cancer

Question 26

what are the three molecular repairs?

Answer 26

1. proteins 2. DNA 3. membrane phospholipids

Question 27

The more paraquat you are exposed to the more what you get?

Answer 27

super oxide anion

Question 28

what happens if only a few mitochondria in a cell get damaged?

Answer 28

those mitochondria will be engulfed, recycled and the cell will survive!

Question 29

mechanisms of toxic cell death: ways xenobitoics can cause cells to die.

Answer 29

1. Impaired ATP synthesis 2. Sustained increase in calcium ion intraceullularly 3. Direct damage to plasma membrane 4. Destroy cytoskeleton 5. Inhibit protein synthesis

Question 30

what allows the paraquat in the lung to get the redox cycling going?

Answer 30

lots and lots of oxygen!

Question 31

when you have damage to mitochondria you get reduced ATP production and increase in intraceullar calcium. What are these things linked to?

Answer 31

RO(N)S

Question 32

describe cellular repair

Answer 32

there is not much for repair usually the cell dies and gets replaced. The only excpetion being our central nervous system where certain neurons can repair cellular damage.

Question 33

out of superoxide anion radica, hydroxyl radicalm and hydrogen peroxide and water which one is the most toxic to us?

Answer 33

hydroxyl radical.

Question 34

oxidoreductive stress can result in what 2 things?

Answer 34

1. direct- oxidative cell injury
2. Indirect- signal transduction gene reguation

Question 35

what is the golden rule for identifying between apoptosis and necrosis

Answer 35

with apoptosis you get a ladder pattern and with necrosis you get a smear pattern!

Question 36

what is an example of something that destroys cytoskeleton?

Answer 36

colchicine