Photochemical effects may cause what kind of cellular damage?

Photochemical effects may cause what kind of cellular damage?

• A. Vascular dilation
• B. Mutagenic and cytotoxic effects
• C. Bacterial infection
• D. Thermal burns

Answer: (B)

Photochemical effects arise when light energy is absorbed by cellular molecules and drives chemical reactions. This can directly damage DNA and other critical cellular components. For example, ultraviolet light can cause DNA lesions like pyrimidine dimers; if these lesions aren’t properly repaired, they can lead to mutations (mutagenic effects) and impaired cell function or cell death (cytotoxic effects). Additionally, photochemical reactions can generate reactive oxygen species, causing oxidative damage to proteins, lipids, and organelles, further contributing to cytotoxic outcomes. This kind of damage is distinct from heating (thermal burns) and from vascular or infectious responses, which aren’t the primary outcomes of photochemical interactions with cellular molecules.

Photochemical effects arise when light energy is absorbed by cellular molecules and drives chemical reactions. This can directly damage DNA and other critical cellular components. For example, ultraviolet light can cause DNA lesions like pyrimidine dimers; if these lesions aren’t properly repaired, they can lead to mutations (mutagenic effects) and impaired cell function or cell death (cytotoxic effects). Additionally, photochemical reactions can generate reactive oxygen species, causing oxidative damage to proteins, lipids, and organelles, further contributing to cytotoxic outcomes. This kind of damage is distinct from heating (thermal burns) and from vascular or infectious responses, which aren’t the primary outcomes of photochemical interactions with cellular molecules.