Module 6

Question 1

Which of the following species is not a free radical or ROS (reactive oxygen species)?

Answer 1

OH-; The other species listed are hydrogen peroxide, H2O2, the hydroxyl radical, HO-, and the superoxide radical, O2-

Question 2

Combustion is a redox process. In this equation representing the complete combustion of a familiar hydrocarbon, C3H8 + 5O2 → 3CO2 + 4H2O, __________ is the reducing agent, __________ is the oxidizing agent, __________ is the oxidized product, and __________ is the reduced product.

Answer 2

propane; oxygen; carbon dioxide; water

Question 3

In the human immune system, macrophages generate __________, __________, and __________, during a process called the oxidative burst. These ROS serve to kill pathogens that the macrophages have ingested.

Answer 3

A. superoxide, hydrogen peroxide, ClO- (hypochlorite ion)

Question 4

Oxygen is converted to the superoxide radical by what enzyme?

Answer 4

NADPH oxidase

Question 5

Superoxide dismutase changes the superoxide into ____, and myeloperoxidase changes some of this into ____, which is the ____ ion

Answer 5

hydrogen peroxide; Cl-; hypochlorite ion

Question 6

In the following complete oxidation-reduction equation, what is the correct form of the oxidation half-reaction? Mg + Cl2 → Mg2+ + 2Cl-

Answer 6

Correct! c. Mg → Mg2 + 2e- (Loss of electrons is oxidation)

Question 7

Another name for an antioxidant is a/an __________. A pro-oxidant could also be called a/an __________.

Answer 7

reducing agent; oxidizing agent;

Question 8

In an oxidation-reduction reaction, the species that gains electrons is said to be __________, and the species that loses electrons is said to be __________. The species that gains electrons is also called the __________ and the species that loses electrons is called the __________.

Answer 8

reduced; oxidized; oxidizing agent; reducing agent

Question 9

In the human body, in order to protect against random free radicals, the enzyme called __________ changes the __________ radical into hydrogen peroxide; and the enzyme called __________ changes the hydrogen peroxide into __________ and __________.

Answer 9

superoxide dismutase; superoxide; catalase; oxygen; water

Question 10

Common oil-soluble dietary antioxidants include __________ and __________; while water-soluble antioxidants include __________ and __________.

Answer 10

carotenoids; Vitamin E; Vitamin C; anthocyanins

Question 11

Question 9 - Which of the following answers correctly lists the different ROS in order from most reactive/shortest half-life to least reactive/longest half-life?

Answer 11

hydroxyl radical; lipid radical; superoxide radical; lipid peroxyl radical; hydrogen peroxide

Question 12

In the process of lipid peroxidation, what does the following equation represent? LH + HO· → H2O + L·

Answer 12

initiation

Question 13

Combustion is a redox process. In this equation representing the complete combustion of a familiar hydrocarbon, C3H8+ 5O2→ 3CO2+ 4H2O, __________ is the reducing agent, __________ is the oxidizing agent, __________ is the oxidized product, and __________ is the reduced product.

Answer 13

propane; oxygen; carbon dioxide; water