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Printable Handouts
Navigable Slide Index
- Introduction
- Metabolism of chlorophylls and related pigments
- Formation of metallo-tetrapyrroles
- Synthesis of 5-aminolevulinate (ALA) (1)
- Synthesis of 5-aminolevulinate (ALA) (2)
- Synthesis of porphobilinogen
- Formation of uroporphyrinogen
- Formation of protoporphyrinogen IX
- Subcellular location of tetrapyrrole synthesis
- Protogen oxidase and membrane destruction
- Subcellular location of tetrapyrrole synthesis
- Cytochrome chromophores
- Siroheme formation
- Phytobilins 1 - plant heme oxygenase
- Phytobilins 2
- Phytobilins 3 - spectral variation
- Formation of Mg protoporphyrin IX
- Formation of protochlorophyllide a
- Synthesis of chlorophylls a and b
- Absorption spectra of equimolar pigment
- Dark and light reduction
- Etiolated and green seedlings
- Photoconversion of Pchlide
- Model of spectral shifts (Oliver and Griffiths 1982)
- Proposal for the reaction mechanism
- Model of the active centre of NADPH
- Formation of chlorophyllide b
- CAO reaction mechanism
- Bacteriochlorophyll a formation
- Prenylation of chlorophyllide a
- Formation of isopentenyl diphosphate (IPP)
- Synthesis of phytol
- Reduction of chlorophyll b
- Degradation of chlorophyll
- The chlorophyll cycle
- Chlorophyll: global overview
- Acknowledgments
Topics Covered
- Metallotetrapyrroles
- C-5 pathway in plants
- C-4 pathway in animals and fungi
- Photodynamic herbicides
- Subcellular location of tetrapyrrole pathways
- Formation of cytochromes, siroheme and phytobilins
- Etioplast-chloroplast transformation
- Two isoprenoid pathways in plant cells
- Chlorophyll cycle
Talk Citation
Rudiger, W. (2021, February 9). Pigments: chlorophyll and its synthesis [Video file]. In The Biomedical & Life Sciences Collection, Henry Stewart Talks. Retrieved December 6, 2024, from https://doi.org/10.69645/QKHC2612.Export Citation (RIS)
Publication History
Financial Disclosures
- Prof. Wolfhart Rudiger has not informed HSTalks of any commercial/financial relationship that it is appropriate to disclose.
Update Available
The speaker addresses developments since the publication of the original talk. We recommend listening to the associated update as well as the lecture.
- Full lecture Duration: 41:51 min
- Update Interview Duration: 20:40 min
A selection of talks on Plant & Animal Sciences
Transcript
Please wait while the transcript is being prepared...
0:00
This talk deals with the metabolism of chlorophyll and
related pigments presented by
Wolfhart Rudiger from the Botanical Institute of the University of Munich.
0:12
The name chlorophyll is derived from the Greek words,
chloros: green, and phyllon: leaf.
It means the green of the leaf.
The name chloroplast is, likewise, derived from this green pigment.
The significance of chlorophyll for life on our globe is commonly known.
The color of chlorophyll is sometimes even used as a synonym for life.
In this sense, the poet,
Johann Wolfgang von Goethe,
apparently refers to chlorophyll with a famous sentence,
"Grau teurer Freund ist alle Theorie und grun des Lebens goldner Baum."
which translates to,
"All theory, dear friend,
is gray, but the precious Tree of Life is green."
Chlorophylls are members of the large group of Metallo-tetrapyrroles;
these have been named the pigments of life because they are widespread in nature
and have important functions as prosthetic groups in many metabolic pathways,
for example, in photosynthesis and respiration.
1:14
Chlorophyll biosynthesis is part of a network of branching pathways,
leading to the formation of various Metallo-tetrapyrroles.
Typically, such a network starts from simple compounds like amino acids.
The first intermediates up to the first branching point are common for all pathways.
Branching points are, uroporphyrinogen III,
protoporphyrin IX, and sirochlorine.
The end products include, amongst others,
iron-containing heme, the prosthetic group of
hemoglobin, of myoglobin, and of many cytochromes.
Siroheme, the prosthetic group of nitrite reductase and sulfite reductase.
Cobalt containing corrinoids of which vitamin B12 is best known,
nickel-containing coenzyme F-430 of Metallo bacteria,
and metal-free phycobilins.
Of these pathways, only those related to chloroplasts will be discussed in this talk.
Typical for photosynthetic organisms are in general,
magnesium-containing chlorophylls and bacteria chlorophylls.
An exception, however, is the genus acidiphilium which is
a group of acidophilic bacteria that photosynthesize under aerobic conditions.
This genus contains zinc bacteriochlorophyll in both the antenna intellection center.
However, because only magnesium-containing bacteria chlorophyll precursors were detected,
one must assume that zinc is introduced in exchange
for magnesium only at a late biosynthetic step,
ending with zinc bacteriochlorophyll and the secondary product of the magnesium branch.
In plants and other plastid containing organisms,
the complete pathway of the magnesium branch is confined to the plastid compartments.
The steps that are common for all branches in
organisms ranging from archaea to eubacteria, to eukarya,
including animals and humans,
these are not only formally identical but also catalyzed
by homologous enzymes that are encoded by homologous genes.
The first specific precursor molecule of tetrapyrroles formation