What are antioxidants?
a) Harmful toxins
b) Proteins that cause inflammation
c) Compounds that prevent cell damage ✅
d) Digestive enzymes Explanation: Antioxidants protect cells from damage caused by free radicals.
Which of the following is a powerful antioxidant vitamin?
a) Vitamin B12
b) Vitamin C ✅
c) Vitamin K
d) Vitamin D Explanation: Vitamin C neutralizes free radicals.
Vitamin E is known for its role as a:
a) Blood thinner
b) Antioxidant ✅
c) Mineral transporter
d) Carbohydrate enzyme Explanation: Vitamin E helps protect cell membranes from oxidation.
Which of the following foods is high in antioxidants?
a) White bread
b) Fried foods
c) Berries ✅
d) Soft drinks Explanation: Berries like blueberries and strawberries are antioxidant-rich.
Free radicals can cause damage to:
a) DNA and cells ✅
b) Muscles only
c) Bones only
d) Hair only Explanation: Free radicals can damage various cellular components, including DNA.
Which of the following is a naturally occurring antioxidant enzyme?
a) Amylase
b) Catalase ✅
c) Lipase
d) Pepsin Explanation: Catalase breaks down hydrogen peroxide, a harmful by-product of metabolism.
A diet high in antioxidants may help prevent:
a) Scurvy only
b) Chronic diseases ✅
c) Only bacterial infections
d) Weight gain Explanation: Antioxidants reduce oxidative stress that contributes to diseases.
Carotenoids act as:
a) Proteins
b) Antioxidants ✅
c) Antibiotics
d) Enzymes Explanation: Carotenoids are plant pigments with antioxidant properties.
Which vitamin is a fat-soluble antioxidant?
a) Vitamin C
b) Vitamin E ✅
c) Vitamin B2
d) Vitamin B12 Explanation: Vitamin E is stored in fat tissues and acts as an antioxidant.
One major function of antioxidants is to:
a) Build muscle
b) Increase blood sugar
c) Reduce oxidative stress ✅
d) Aid digestion Explanation: Antioxidants neutralize oxidative damage from free radicals.
🟡 Moderate Level (11–20)
Flavonoids found in plants function primarily as:
a) Digestive aids
b) Antioxidants ✅
c) Proteins
d) Carbohydrates Explanation: Flavonoids are plant compounds with antioxidant effects.
Selenium is important in the diet because:
a) It boosts cholesterol
b) It acts as an antioxidant ✅
c) It prevents bone loss
d) It helps in fat storage Explanation: Selenium works with enzymes to reduce oxidative stress.
Which vitamin works closely with vitamin E to regenerate its antioxidant capacity?
a) Vitamin A
b) Vitamin D
c) Vitamin C ✅
d) Vitamin K Explanation: Vitamin C helps recycle oxidized vitamin E.
Which fruit is considered a good source of antioxidants?
a) Banana
b) Apple
c) Pomegranate ✅
d) Potato Explanation: Pomegranate contains high levels of polyphenols and flavonoids.
Antioxidants help to protect against which of the following?
a) Sunburn only
b) Oxidative damage ✅
c) All bacterial infections
d) Hair fall Explanation: Antioxidants combat oxidative damage from free radicals.
Beta-carotene is a precursor of:
a) Vitamin C
b) Vitamin E
c) Vitamin A ✅
d) Vitamin B12 Explanation: Beta-carotene is converted into vitamin A in the body.
Resveratrol is an antioxidant commonly found in:
a) Grapes ✅
b) Milk
c) Eggs
d) Bread Explanation: Found in grape skins and red wine, resveratrol has antioxidant effects.
Oxidative stress results when:
a) Antioxidants exceed free radicals
b) Free radicals exceed antioxidants ✅
c) Fatty acids are low
d) Blood pressure rises Explanation: Oxidative stress occurs when free radicals overwhelm the body’s defense.
Which mineral works as a cofactor for antioxidant enzymes?
a) Calcium
b) Zinc ✅
c) Phosphorus
d) Chloride Explanation: Zinc supports enzymes like superoxide dismutase.
Polyphenols are found in:
a) Processed meat
b) Green tea ✅
c) Soda
d) Cheese Explanation: Polyphenols are abundant in tea, fruits, and vegetables.
🔴 Hard Level (21–30)
Which antioxidant enzyme catalyzes the breakdown of superoxide radicals?
a) Amylase
b) Superoxide dismutase ✅
c) Lipase
d) Trypsin Explanation: Superoxide dismutase (SOD) converts superoxide into less reactive molecules.
Which is NOT a function of antioxidants?
a) Neutralize free radicals
b) Prevent oxidative cell damage
c) Provide structural cell support ✅
d) Reduce aging signs Explanation: Antioxidants do not provide structural support; they reduce oxidative stress.
Lycopene is a powerful antioxidant found in:
a) Apples
b) Tomatoes ✅
c) Cucumber
d) Milk Explanation: Lycopene gives tomatoes their red color and fights oxidative stress.
Curcumin, found in turmeric, functions as a:
a) Protein
b) Carbohydrate
c) Antioxidant ✅
d) Mineral Explanation: Curcumin is an active antioxidant compound in turmeric.
Which vitamin is most sensitive to heat and light, thus easily destroyed?
a) Vitamin A
b) Vitamin C ✅
c) Vitamin D
d) Vitamin E Explanation: Vitamin C degrades quickly when exposed to heat and light.
Astaxanthin is an antioxidant found in:
a) Green vegetables
b) Red meat
c) Salmon and shrimp ✅
d) Milk Explanation: Astaxanthin is a red pigment in marine animals with strong antioxidant power.
The antioxidant glutathione is composed of which amino acids?
a) Leucine, isoleucine, valine
b) Glutamine, glycine, cysteine ✅
c) Histidine, serine, tyrosine
d) Alanine, threonine, lysine Explanation: These three form glutathione, a key antioxidant.
What is the main site of antioxidant defense in the body?
a) Blood
b) Skin
c) Cells ✅
d) Stomach Explanation: Antioxidants act at the cellular level to protect DNA and membranes.
Excess intake of antioxidant supplements can cause:
a) Greater health benefits
b) Toxicity and cell damage ✅
c) Faster weight loss
d) No effect Explanation: Over-supplementation may lead to oxidative imbalance.
Which antioxidant is synthesized by the body and found in almost every cell?
a) Vitamin C
b) Vitamin A
c) Glutathione ✅
d) Beta-carotene Explanation: Glutathione is the body’s master antioxidant.