Peroxisomes and Lysosomes: Intracellular Defense

The video tutorial covers the roles of peroxisomes and lysosomes in cellular defense. Peroxisomes help break down hydrogen peroxide using catalase, preventing damage from its reactive nature. The tutorial explains the dangers of hydrogen peroxide, including its reactions with UV light and iron, leading to harmful radicals. Lysosomes are highlighted for their role in phagocytosis, engulfing bacteria and breaking them down using enzymes, acid, and reactive oxidative species. The synthesis of these species is crucial for destroying microbes, showcasing the cellular defense mechanisms.

What is the primary function of peroxisomes in cells?

• To synthesize proteins

• To store nutrients

• To produce ATP

• To manage hydrogen peroxide

Which enzyme in peroxisomes breaks down hydrogen peroxide into harmless substances?

• Protease

• Catalase

• Amylase

• Lipase

What harmful radicals can hydrogen peroxide form under UV light?

• Peroxyl radicals

• Nitric oxide radicals

• Superoxide radicals

• Hydroxyl radicals

What is the main role of lysosomes in cellular defense?

• To protect against bacteria

• To store calcium

• To produce glucose

• To synthesize lipids

During phagocytosis, what structure is formed when a lysosome fuses with a phagocytic vesicle?

• Golgi body

• Phagolysosome

• Endosome

• Peroxisome

Which of the following is NOT a method used by lysosomes to degrade bacteria?

• Acidity

• Proteases

• Photosynthesis

• Reactive oxidative species

How do lysosomes use acidity to aid in bacterial degradation?

• By storing lipids

• By increasing pH

• By denaturing proteins

• By synthesizing DNA

What is the role of reactive oxidative species in lysosomes?

• To transport nutrients

• To synthesize proteins

• To damage and destroy bacteria

• To store energy

Which enzyme is responsible for the initial step in the synthesis of reactive oxidative species in lysosomes?

• Amylase

• NADPH oxidase

• Catalase

• Lipase

What is the difference between peroxisomes and lysosomes in terms of hydrogen peroxide?

• Lysosomes synthesize hydrogen peroxide for energy

• Peroxisomes protect the cell from hydrogen peroxide

• Lysosomes protect the cell from hydrogen peroxide

• Peroxisomes generate hydrogen peroxide for bacterial damage