Chlorophyll Fluorescence

Chlorophyll + hν (blue/red) → Chlorophyll* → Chlorophyll + hν (red)

Overview

Chlorophyll absorbs blue (430 nm) and red (660 nm) light, reaching an excited singlet state. Most energy is transferred to the photosynthetic reaction center, but a small fraction (1–2%) is re-emitted as red fluorescence (680–740 nm). This fluorescence is a direct indicator of photosynthetic efficiency.

Everyday Example

If you shine a UV light on a spinach extract, it glows red due to chlorophyll fluorescence — a common chemistry demonstration.

Industrial Importance

Chlorophyll fluorescence measurement (PAM fluorometry) is used in agriculture, forestry, and ecology to assess plant health and stress.

Properties

Type: Photochemical
Reversible: Yes
Energy: Exothermic

Related Reactions

Cis-Trans Isomerization of Retinal Dye-Sensitized Solar Cell (Grätzel Cell) Firefly Bioluminescence (Luciferin Oxidation) Luminol Chemiluminescence Ozone Decomposition by UV Ozone Formation by UV Light Photocatalytic NOx Removal Photocatalytic Water Splitting (TiO₂) Photochemical Cycloaddition ([2+2]) Photochemical Smog Formation (NO₂ Photolysis)

Frequently Asked Questions

What is the equation for Chlorophyll Fluorescence?

The balanced equation is: Chlorophyll + hν (blue/red) → Chlorophyll* → Chlorophyll + hν (red).

What type of reaction is Chlorophyll Fluorescence?

Chlorophyll Fluorescence is a photochemical reaction. It is reversible under certain conditions.

Is Chlorophyll Fluorescence exothermic or endothermic?

Chlorophyll Fluorescence is exothermic (releases energy).