OBT Photobiomodulation Mechanisms & Cellular Effects

Question 1

Which cellular organelle is considered the primary chromophore target for photobiomodulation in the red and near-infrared wavelength range?

Accepted Answer

Cytochrome c oxidase in mitochondria

Answer

Nucleus

Answer

Golgi apparatus

Answer

Endoplasmic reticulum

Question 2

What primary cellular energy molecule increases following photobiomodulation of mitochondria?

Accepted Answer

ATP

Answer

ADP

Answer

NADH

Answer

GTP

Question 3

The therapeutic window for photobiomodulation typically spans which wavelength range?

Accepted Answer

600–1100 nm (red/near-infrared)

Answer

200–400 nm (UV)

Answer

400–500 nm (violet/blue)

Answer

1200–1500 nm (mid-infrared)

Question 4

Reactive oxygen species (ROS) produced in low, non-toxic amounts during photobiomodulation primarily serve as:

Accepted Answer

Second messengers that activate signaling pathways

Answer

Cellular toxins that destroy pathogens

Answer

Indicators of excessive dosage

Answer

Byproducts of melanin degradation

Question 5

Which transcription factor is commonly upregulated following photobiomodulation-induced ROS signaling?

Accepted Answer

NF-κB

Answer

p53

Answer

CREB

Answer

STAT3

Question 6

The Arndt-Schulz Law as applied to photobiomodulation states that:

Accepted Answer

Small stimuli excite biological activity while large doses inhibit it

Answer

Higher doses always produce greater biological responses

Answer

Light must be coherent to produce therapeutic effects

Answer

Wavelength determines penetration depth exclusively

Question 7

Which of the following best describes the process of 'photoactivation' in photobiomodulation therapy?

Accepted Answer

Non-thermal absorption of photons by endogenous chromophores triggering biochemical changes

Answer

Heating of tissue to denature proteins

Answer

Ionization of cellular water molecules

Answer

Stimulated emission of radiation from excited atoms