Redox reactions Flashcards

1
Q

Free radicals are..?

A

Small, diffusible, very reactive, short lives, unstable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the order of ROS?

A

hydrogen peroxide, superoxide anion and then hydroxyl radical (least to most)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How are ROS generated in mitochondria?

A

Mitochondria (e- transport chain - complex I and III) - autooxidation of ubisemiquinone (this is a free radical) which releases superoxide into matrix and intermembrane space. Can etner the cytoplasm through VDAC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How are ROS generated in cytoplasm?

A

Xanthine dehydrogenas (XDH) generates hydrogen peroxide whilst creating uric acid and xanthine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How are ROS generated in plasma membrane?

A

NADPH oxidase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are positive effects of free radicals?

A

signal energy overload and decrease energy uptake
oxidize iodide to iodine
Kill pathogens, clean up cells and debris

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does detoxification of superoxide anion radical occur?

A

By SOD changing it to hydrogen peroxide and then GPO and CAT converting it too water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what do antioxidants do?

A

Prevent e- transfer from o2 to organic molecules

stabilize free radicals and terminate free radical reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is SOD

A

superoxide dismutase
produces hydrogen peroxide from superoxide anion
MnSOD (mito) and CuZn SOD (cyto and mito)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is GSH-PX?

A

Glutathione peroxidase
converts hydrogen peroxide to water
requires GSH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is GSH?

A

non-protein thiol

has roles in immune, proliferation, redox balance and prostaglandin metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is catalase

A

heme-containing enzyme making H2O2 to H2O

requires NADPH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

WHat are negative ROS effects?

A

DNA damage, Lipid damage and protein damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How can you detect superoxide?

A

MitoSOX red dye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is electorn spin resonance?

A

Detects microwave energy absorption and can change with free radicals. Uses EMPO ato make them more stable for measurement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is amplex red?

A

Dye used to detect H2O2 released from a sample

17
Q

How does doxorubicin generate cardiotoxicity?

A

structure is prone to ROS generation, also related to decerase in antioxidants (endogenous) resulting in increase oxidative stress