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How do chloroplasts capture light energy for algae?

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“mermaid's wine glass” algae — Algae The macroscopic genus of algae known as *Acetabularia* is commonly called “mermaid's wine glass” because of the distinctive umbrella-like shape of the tips of its stalks.

In algae, chloroplasts serve as the specialized organelles where photosynthesis occurs, converting light energy into chemical energy. This process relies on the structural organization of the chloroplast, specifically the thylakoids—hollow, disk-like internal membranes where light reactions take place.12

Light energy is captured by various pigments embedded within these membranes. All algae utilize chlorophyll a to harvest photosynthetically active light, while many species employ additional pigments to capture wavelengths that chlorophyll a cannot absorb. These include:32

Chlorophyll b: Used by green algae and euglenophytes.3
Carotenoids: Primarily absorb blue and green light; common in dinoflagellates and chromophyte algae.3
Phycobiliproteins: Found in red algae and cryptomonads, these pigments absorb blue or red light.3

By concentrating these pigments within the thylakoid membranes, algae efficiently harvest light energy to drive the electron transport necessary for producing the chemical energy required for carbon fixation in the stroma.32