cyanophycin Flashcards
What are the two layers which compose cyanophyceae
cyanophyceae is composed of two inner layers L1 and L2 even if all the structure of other cyanophyceae are different L1 and L2 are the only 2 layers that are similar for all the organisms
What are the two layers which compose cyanophyceae
cyanophyceae is composed of two inner layers L1 and L2 even if all the structure of other cyanophyceae are different L1 and L2 are the only 2 layers that are similar for all the organisms
What is the structure of L2 depend on
Structure of L2 depends on environmental conditions and the amount of mucilage secreted
Types of mucilage layer
The mucilage layer is of two types sheets and capsule the shit protects sell from dying it also helps the cell to glide it acts as a neutral sugar uric acid galactose glucose gluconic acid etc the capsule makes the cell wall also called lichen marine glycopetite mucopleptide
what are the two photosystems practiced by cyanophyceae
ps 1 and ps 2
what us ps1
Photosystem I (PSI):
PSI absorbs light energy to further excite electrons, which are then used to reduce NADP+ to NADPH. PSI contains pigments like chlorophyll a and carotenoids.
what is ps2
Photosystem II (PSII):
PSII is responsible for splitting water molecules (photolysis), producing oxygen, electrons, and protons.
It absorbs light through pigments like chlorophyll a and phycobilins (especially phycocyanin and phycoerythrin) and initiates the electron transport chain by transferring electrons to a plastoquinone.
tell me about Thylakoids and Phycobilisomes
Thylakoids: Cyanobacteria have thylakoid membranes but no chloroplasts. Photosynthesis occurs on these thylakoid membranes, which are arranged throughout their cells.
Phycobilisomes: These protein complexes attached to the thylakoid membranes contain pigments that help in absorbing light, especially in environments with low light, aiding in efficient photosynthesis.
what are Phycobiliproteins, phycocyanin, and allophycocyanin
are pigments found in cyanobacteria (Cyanophyceae) and some algae, playing a crucial role in photosynthesis.
Phycobiliproteins:
These are water-soluble proteins that serve as light-harvesting pigments in cyanobacteria and red algae.
They are organized into complexes called phycobilisomes, which are attached to the surface of the thylakoid membranes.
The primary role of phycobiliproteins is to capture light energy and transfer it to chlorophyll, enhancing the efficiency of photosynthesis.
They include several types, mainly phycocyanin, allophycocyanin, and phycoerythrin, each absorbing different wavelengths of light.
Phycocyanin
type of phycobiliprotein that has a blue color and absorbs light primarily in the orange to red region (around 620 nm).
It plays a significant role in the light-harvesting process of photosynthesis by transferring the absorbed light energy to chlorophyll.
Phycocyanin is commonly found in cyanobacteria, and it gives these organisms their characteristic blue-green color.
What is a cyanoprokaryote
It is a primitive group of algae consisting of 150 genre and 2500 species. In India the division is represented by 98 general and 833 species numbers of class myxophyceae are commonly known as blue green algae. The name blue green algae is given because of the presence of dominant pigment c-phycocyanin, the blue green pigment
What is a prokaryote
Nucleus is of prokaryotic nature that is devoid of nuclear membrane and nucleolus
absence of well organised cell organelles
pigments are distributed throughout the chromoplasm are the outer part of Protoplasm
Mention some important characteristics of cyanophycea
Membrane bound chromatophores are absent.
Pigments are found embedded in thylakoids
The Reserve foods are cyanophycean starch and cyanophycean granules or protein.
many filamentous members possess specialised cells of disputed function known as Hstrocyst.
reproduction takes place by vegetative and asexual methods.
vegetative reproduction takes place by cell division fragmentation etc esexual reproduction takes place by endospers exospores nannospers akinetes
sexual reproduction is completely absent genetic recombination is reported in two cases
Both vegetative and reproductive cells are non flagellate
cell wall is made of microfibrils and is differentiated into four layers. the cell wall is composed of mucopeptide along with carbohydrates, amino acid and fatty acids.
locomotion and generally absent but when it occurs it is gliding a jerky type.
The principle pigments are chlorophyll a, c-phycocyanin and c-phyco-erythrin. in addition other pigments like be beta carotene and different xanthophylls like myxoxanthin and myxoxanthophyll are present
the individual cells are prokaryotic in nature the nucleus is incipenr type and they lack membrane bound organelles
