Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BioChem 2 Exam 2 > ROS, Free Radicals > Flashcards

ROS, Free Radicals Flashcards

1
Q

What is important about the nature of Oxygen

A

Oxygen is a bi-radical. It supports life and bears toxicity. Oxygen toxicity results from reactive oxygen species and free radicals.

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

What are free Radicals?

A

Atomic or molecular species which are extremely reactive because they have an unpaired electron.

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

How are Reactive Oxygen Species generated?

A

By one-electron transfers.

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

Which mechanisms overlap with the antioxidant system, and are one of the biggest generators of free radicals?

A

Detoxification Mechanisms

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

Identify types Reactive Oxygen Species.

A

Superoxide Anion, Hydrogen Peroxide, Hydroxyl Radical, Organic Radical, Organic Peroxide Radical, Hypochlorous Acid, and Singlet Oxygen

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

What is the Fenton Reaction?

A

The decomposition of a metal (Fe2+) to produce Hydroxyl Radical and hydroxide ion.

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

Who is considered the “Bad Actor”

A

Mr. Hydroxyl Radical…he is the most destructive

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

What are some endogenous sources of free radicals in the body?

A

Enzyme Activity, Electron Transport Chain, Phagocytic Respiratory Burst

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

What are some exogenous sources of free radical?

A

UV Radiation, Drugs, air pollutants

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

What is a normal biological process that can generate superoxide?

A

The electron transport chain

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

What is the biggest offender in the electron transport chain in generating free radicals?

A

COQ…because it is not protected and it most abundant. COQ is reduced in an anaerobic state.

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

Why do some cells of the immune system purposely produce ROS?

A

To destroy bacteria

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

True or False? Lipids are not susceptible to free radical damage.

A

False

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

Oxidation involves the removal of ____ _____from unsaturated fatty acids.

A

Hydrogen radicals

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

Which Fatty Acids are most susceptible to oxidative damage?

A

Polyunsaturated Fatty Acids (PUFA)…monounsaturated FA are as well (ex. Olive Oil)

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

What are two types of free radical damage to PUFA?

A
  1. Decomposition to bi-functional aldehydes and/or alpha, beta-unsaturated aldehydes…which can form adducts or crosslink other biomolecules
  2. Reacting with Sulfhydryl groups on enzymes.
    (refer to page 47 for reaction)
17
Q

What are the 4 phases of the free radical damage mechanism?

A

Initiation, propagation, degradation, termination

18
Q

What is an allylic radical?

A

a radical between double bonds. It is a more stable radical form. Electrons are not shared across all 3 carbons.

19
Q

What is the 1st line of defense for cells to protect themselves against free radical damage/oxidative toxicity?

A

Antioxidant Enzymes: Glutathione peroxidase, superoxide dismutase, and catalase.

20
Q

What is the 2nd line of defense for cells to protect themselves against free radical dmage and oxidative toxicity?

A

Vitamins E and C, and other free radical scavengers

21
Q

What are the cellular locations?

A

Mitochondria, Peroxisomes, and Cytosol

22
Q

What are the tissue Locations?

A

Liver (most abundant), adrenals, kidneys

23
Q

In humans, the Cu, Zn superoxide dismutase is found where?

A

In the Cytosol

24
Q

The Manganese SOD is found where?

A

In the mitochondrion

25
Q

Ascorbic Acid aka…?

A

Vitamin C

26
Q

Where does absorption of Vitamin C occur?

A

The distal small intestine through a sodium-dependent ascorbate transporter (SVCT)

27
Q

True or false? Most cells acquire Vitamin C by SVCT2 or GLUT transporters.

A

True.

28
Q

Which specific GLUT transporters do cells acquire Vitamin C?

A

GLUT 1 and GLUT 3

29
Q

What does Ascorbate neutralize?

A

Radical Oxygen and Nitrogen Species, Peroxides and superoxides

30
Q

True or false? The Ascorbate radical is very unstable.

A

False.

31
Q

What reducing agents are involved in the regeneration of the reduced form of Vitamin C?

A

NADH or Glutathione

32
Q

What are the enzymes that CAN be involved in the regeneration of the reduced form of Vitamin C? Of these, how many are required?

A

NADH reductase, Dehydroascorbate reductase, Thioredoxin reductase. At least one is required for the regeneration.

33
Q

Vitamin C can go to Oxalic Acid, which will cause?

A

Kidney stones

34
Q

Vitamin E helps protect?

A

Membranes and lipoproteins

35
Q

True or false? The Vitamin E radical is stable.

A

True.

36
Q

What does the Cellular Redox Cycle regenerate?

A

Reduced Vitamin E from reduced Vitamin C.

37
Q

How does Vitamin E get exposed to Vitamin C?

A

On the surface of membranes

38
Q

Which cycle resets the radical scavengers to their reduced form?

A

The Thiol Cycle

BioChem 2 Exam 2 (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions