12. Woodward’s Synthesis of Chlorophyll - Chemistry …
Biosynthesis Fatty acids | Biosynthesis | Fatty Acid
Plastids are a group of organelles that are characteristic of plant cells. They have derived in an endosymbiotic event from a cyanobacterial ancestor and still exhibit many prokaryotic features. Plastids are able to perform many specialised functions that are essential for plant growth and development, such as photosynthesis, nitrate and sulfate assimilation, the synthesis of amino acids and of fatty acids, storage of carbohydrates and lipids or the formation of colours in some fruits and flowers. To accomplish this, their membrane systems exert specialised transport functions, including the import and sorting of proteins and the exchange of metabolites in case of the two envelope membranes, as well as proton and electron transport in the case of the thylakoid membranes of chloroplasts. Moreover, plastids communicate with the nucleus by retrograde signalling to adjust the expression of nuclear genes according to the metabolic and developmental state of the organelle.
Chlorophyll Metabolism - eLS: Essential for Life Science
Flow chart of the metabolic pathway of tetrapyrrole biosynthesis towards the end products, chlorophyll and protohaem. Potential feedback control mechanisms in the metabolic pathway of tetrapyrroles are indicated. The synthesis of 5‐aminolaevulinate from glutamate is the rate‐limiting step of tetrapyrrole biosynthesis. Feedback regulation on the enzymes of the 5‐aminolevulinic acid pathway can start out from various sites: at the level of haem formation, at the level of protochlorophyllide reduction and at the beginning of the Mg‐porphyrin branch.