Related Experiment Video
Updated: Nov 8, 2025

Measuring Photophysiology of Attached Stage of Colacium sp. by a Cuvette-Type Fast Repetition Rate Fluorometer
Published on: November 12, 2021
Functional aspects of secondary carotenoids in Haematococcus lacustris (Girod) Rostafinski (Volvocales): I. The
C Hagen1, W Braune1, E Birckner2
1Institute of General Botany, Friedrich Schiller University Jena, von Hase-Weg 3, D-07743 Jena, Germany.
Abstract:
Alterations of photosynthetic activity were investigated during accumulation of secondary carotenoids in Haematococcus lacustris (Girod) Rostafinski. Using several methods regarding (i) pigment pattern and pigment content (cytophotometry, computer-aided microscopic image analysis, in vivo absorption spectroscopy, high-performance liquid chromatrography) and (ii) photosynthesis (microfluorometry, modulated chlorophyll fluorescence and luminescence detection, O2 evolution and consumption measurement, 77 K fluorescence spectroscopy) we examined single cells and cell suspensions of the green alga. The results indicate decrease of both the photosystem II activity and the linear electron transport accompanying synthesis of secondary carotenoids. On the other hand, activation of those processes leading to an increased transthylakoid proton gradient could be established during early accumulation period. This is assumed to be an active adaptation of the photosynthetic apparatus to energetic requirements given by secondary carotenoid biosynthesis in H. lacustris.
Related Concept Videos
Secondary Active Transport
Secondary Active Transport
The Antenna Complex
Drug Metabolism: Phase II Reactions
Role of Skin in Vitamin D Synthesis
The solar UV B rays (290-315 nm) are absorbed by the skin, and 7-dehydrocholesterol (provitamin D3) photolyzes it to previtamin D3, which undergoes a rapid transformation to vitamin...
Photosystems
Functioning of Photosystems
Photosystems contain many pigment molecules, such as chlorophylls and carotenoids, arranged in a particular organization across two domains — the antenna complex and the reaction center. The main aim of the pigment...

