Understanding Oxygen and Its Effects

What percentage of the air we breathe is composed of oxygen?

• 78%

• 21%

• 1%

• 50%

What is a by-product of cellular respiration that can cause damage to cells?

• Carbon dioxide

• Nitrogen

• Free radicals

• Antioxidants

How do antioxidants help the body?

• They dissolve in water.

• They produce energy.

• They neutralize free radicals.

• They increase oxygen levels.

What role does nitrogen play in the lungs?

• It dissolves in the blood.

• It produces energy.

• It helps keep the lungs inflated.

• It reacts with oxygen.

What could happen if you breathe pure oxygen for an extended period?

• Improved lung function

• Lung collapse

• Increased energy levels

• Enhanced cellular respiration