A report on Hornwort and Pyrenoid

Cross section of a Chlamydomonas reinhardtii algae cell, a 3D representation
Life cycle of a typical hornwort Phaeoceros. Click on the image to enlarge.
DIC image of Scenedesmus quadricauda with the pyrenoid (central four circular structures) clearly visible.
The hornwort Dendroceros crispus growing on the bark of a tree.
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Pyrenoids are sub-cellular micro-compartments found in chloroplasts of many algae, and in a single group of land plants, the hornworts.

- Pyrenoid

In half of the roughly 200 hornwort species, this chloroplast is fused with other organelles to form a large pyrenoid that both enables more efficient photosynthesis and stores food.

- Hornwort

2 related topics with Alpha

Overall

Chloroplasts visible in the cells of Bryum capillare, a type of moss

Chloroplast

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Type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells.

Type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells.

Chloroplasts visible in the cells of Bryum capillare, a type of moss
Euglena, a euglenophyte, contains secondary chloroplasts from green algae.
Chlorarachnion reptans is a chlorarachniophyte. Chlorarachniophytes replaced their original red algal endosymbiont with a green alga.
Scanning electron micrograph of Gephyrocapsa oceanica, a haptophyte.
The photosynthetic pigments present in their chloroplasts give diatoms a greenish-brown color.
Ceratium furca, a peridinin-containing dinophyte
Karenia brevis is a fucoxanthin-containing dynophyte responsible for algal blooms called "red tides".
Dinophysis acuminata has chloroplasts taken from a cryptophyte.
Chloroplast DNA replication via multiple D-loop mechanisms. Adapted from Krishnan NM, Rao BJ's paper "A comparative approach to elucidate chloroplast genome replication."
Over time, base changes in the DNA sequence can arise from deamination mutations. When adenine is deaminated, it becomes hypoxanthine, which can pair with cytosine. During replication, the cytosine will pair with guanine, causing an A --> G base change.
Transmission electron microscope image of a chloroplast. Grana of thylakoids and their connecting lamellae are clearly visible.
Instead of an intermembrane space, glaucophyte algae have a peptidoglycan wall between their inner and outer chloroplast membranes.
Granum-stroma assembly structure The prevailing model of the granum-stroma assembly is stacks of granal thylakoids wrapped by right-handed helical stromal thylakoids which are connected to large parallel sheets of stromal thylakoids and adjacent right-handed helices by left-handed helical structures. (Based on ).
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Some contain pyrenoids.

The chloroplasts of some hornworts and algae contain structures called pyrenoids.

Schematic of photosynthesis in plants. The carbohydrates produced are stored in or used by the plant.

Photosynthesis

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Process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities.

Process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities.

Schematic of photosynthesis in plants. The carbohydrates produced are stored in or used by the plant.
Composite image showing the global distribution of photosynthesis, including both oceanic phytoplankton and terrestrial vegetation. Dark red and blue-green indicate regions of high photosynthetic activity in the ocean and on land, respectively.
Photosynthesis changes sunlight into chemical energy, splits water to liberate O2, and fixes CO2 into sugar.
Light-dependent reactions of photosynthesis at the thylakoid membrane
The "Z scheme"
Overview of the Calvin cycle and carbon fixation
Overview of C4 carbon fixation
Plant cells with visible chloroplasts (from a moss, Plagiomnium affine)
Portrait of Jan Baptist van Helmont by Mary Beale, c.1674
Melvin Calvin works in his photosynthesis laboratory.
The leaf is the primary site of photosynthesis in plants.
Absorbance spectra of free chlorophyll a ( blue ) and b ( red ) in a solvent. The action spectra of chlorophyll molecules are slightly modified in vivo depending on specific pigment–protein interactions.
Photorespiration

Pyrenoids in algae and hornworts also act to concentrate around RuBisCO.