Light absorption

Question 1

What are the three chlorophylls and what is the difference between them

Answer 1

Chl a and b are tetrapyrroles with Mg and differ at the methyl group position. Chlc (1 to 3)

Question 2

What are carotenoids

Answer 2

Two types: carotenes (hydrocarbons) and xanthophylls (majority, contain oxygen)
Most important light harvesting carotenoids are fucoxanthin and derivatives and peridinin

Question 3

What are photoprotective pigments

Answer 3

Carotenoids that protects chl from harmful effects of high irradiance in the presence of oxygen (ROS), O is integrated into the carotenoids. Low lights promotes epooxidation (Diadinoxanthin and Violacanthin), high light promotes deepoxidation (diatoxanthin and zeaxanthin)

Question 4

What is the photoprotective reaction in prasinophytes chlorophytes, phaeophytes

Answer 4

Violaxanthin (2 epoxides –> Antheraxanthin (1 epoxide) –> Zeaxanthin

Question 5

What is the photoprotective reaction in diatoms, dinoflagellates, prymnesiophytes, euglenophytes and chrysophytes

Answer 5

Diadinoxanthin (1 epoxide) –> diatoxanthin

Question 6

What are phycobiliproteins and what are there characteristics

Answer 6

Light harvesting pigments in cyanobacteria, cryptophyceae and rhodophyceae
Four types: Phycocyanin, phycoerythrin, allophycocyanin and phycoerythocyanin
PBS are soluble in water, not in lipid solutions

Question 7

What is the difference between in situ and in vitro pigment absorption

Answer 7

Different shape of spectra
Different peaks due to no coupling to other proteins
No scattering,no yellow substabce

Question 8

What is a*phi (lambda), and FPSII

Answer 8

a*phi (lambda) = chl a specific absorption coefficient/Chla specific absorption spectrum shows the total amount of light absorped FPSII is the Chla specific PSII scaled fluorescence excitation spectra and shows the fratcion of light received by PSII
The difference is indicating the non fluorescent fraction

Question 9

What is photoacclimation characterized by

Answer 9

Changes in ratios of LHP and photoprotective pigments
PS parameters
Enzymatic activity
Cell volume and chemical composition

Question 10

How is the photoacclimation acitvated

Answer 10

Lowering of pH in the lumen, optimal pH for activity of the epoxidase enzyme activity

Question 11

What are the main carotenoids in lobster

Answer 11

Blue astaxanthin and green astaxanthin

Question 12

What was the bloom in August 2004?

Answer 12

E. huxleyi bloom detected by high resolution satellite images

Question 13

What is chemotaxonomy

Answer 13

Verification of phytoplankton pigment groups for identification of phytoplankton (blooms)