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Plant Biochemistry

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Plant Biochemistry
-:- A leaf cell consists of several metabolic compartments
-:- The cell wall gives the plant cell mechanical stability
-:- Vacuoles have multiple functions
-:- Plastids have evolved from cyanobacteria
-:- Mitochondria also result from endosymbionts
-:- Peroxisomes are the site of reactions in which toxic intermediates are formed
-:- The endoplasmic reticulum and golgi apparatus form a network for the distribution of biosynthesis products
-:- Functionally intact cell organelles can be isolated from plant cells
-:- Various transport processes facilitate the exchange of metabolites between different compartments
-:- Translocators catalyze the specific transport of metabolic substrates and products
-:- Ion channels have a very high transport capacity
-:- Porins consist of β-sheet structures
-:- The use of energy from sunlight by photosynthesis is the basis of life on earth
-:- How did photosynthesis start?
-:- Pigments capture energy from sunlight
-:- The energy content of light depends on its wavelength
-:- Chlorophyll is the main photosynthetic pigment
-:- Light absorption excites the chlorophyll molecule
-:- An antenna is required to capture light
-:- How is the excitation energy of the photons captured in the antennae and transferred to the reaction centers?
-:- The function of an antenna is illustrated by the antenna of photosystem II
-:- Phycobilisomes enable cyanobacteria and red algae to carry out photosynthesis even in dim light
-:- The photosynthetic machinery is constructed from modules
-:- A reductant and an oxidant are formed during photosynthesis
-:- The basic structure of a photosynthetic reaction center has been resolved by X-ray structure analysis
-:- How does a reaction center function?
-:- Two photosynthetic reaction centers are arranged in tandem in photosynthesis of algae and plants
-:- Water is split by photosystem II
-:- The cytochrome-b6/f complex mediates electron transport between photosystem II and photosystem I
-:- Photosystem I reduces NADP
-:- In the absence of other acceptors electrons can be transferred from photosystem I to oxygen
-:- Regulatory processes control the distribution of the captured photons between the two photosystems
-:- A proton gradient serves as an energy-rich intermediate state during ATP synthesis
-:- The electron chemical proton gradient can be dissipated by uncouplers to heat
-:- H -ATP synthases from bacteria, chloroplasts, and mitochondria have a common basic structure
-:- The synthesis of ATP is effected by a conformation change of the protein
-:- Biological oxidation is preceded by a degradation of substrates to form bound hydrogen and CO2
-:- Mitochondria are the sites of cell respiration
-:- Degradation of substrates applicable for biological oxidation takes place in the matrix compartment
-:- How much energy can be gained by the oxidation of NADH?
-:- The mitochondrial respiratory chain shares common features with the photosynthetic electron transport chain
-:- Electron transport of the respiratory chain is coupled to the synthesis of ATP via proton transport
-:- Plant mitochondria have special metabolic functions
-:- Compartmentation of mitochondrial metabolism requires specific membrane translocators
-:- CO2 assimilation proceeds via the dark reaction of photosynthesis
-:- Ribulose bisphosphate carboxylase catalyzes the fixation of CO2
-:- The reduction of 3-phosphoglycerate yields triose phosphate
-:- Ribulose bisphosphate is regenerated from triose phosphate
-:- Besides the reductive pentose phosphate pathway there is also an oxidative pentose phosphate pathway
-:- Reductive and oxidative pentose phosphate pathways are regulated
-:- Starch is synthesized via ADP-glucose
-:- Degradation of starch proceeds in two different ways
-:- Surplus of photosynthesis products can be stored temporarily in chloroplasts as starch
-:- Sucrose synthesis takes place in the cytosol
-:- The utilization of the photosynthesis product triose phosphate is strictly regulated
-:- In some plants assimilates from the leaves are exported as sugar alcohols or oligosaccharides of the raffinose family
-:- Fructans are deposited as storage compounds in the vacuole
-:- Cellulose is synthesized by enzymes located in the plasma membrane
-:- Nitrate assimilation is essential for the synthesis of organic matter
-:- The reduction of nitrate to NH3 proceeds in two reactions
-:- Nitrate assimilation also takes place in the roots
-:- Nitrate assimilation is strictly controlled
-:- The end product of nitrate assimilation is a whole spectrum of amino acids
-:- Glutamate is the precursor for chlorophylls and cytochromes
-:- Nitrogen fixation enables plants to use the nitrogen of the air for growth
-:- Legumes form a symbiosis with nodule-inducing bacteria
-:- N2 fixation can proceed only at very low oxygen concentrations
-:- The energy costs for utilizing N2 as a nitrogen source are much higher than for the utilization of NO3-
-:- Plants improve their nutrition by symbiosis with fungi
-:- Root nodule symbioses may have evolved from a pre-existing pathway for the formation of arbuscular mycorrhiza
-:- Sulfate assimilation enables the synthesis of sulfur containing compounds
-:- Sulfate assimilation proceeds primarily by photosynthesis
-:- Glutathione serves the cell as an antioxidant and is an agent for the detoxification of pollutants
-:- Methionine is synthesized from cysteine
-:- Excessive concentrations of sulfur dioxide in the air are toxic for plants
-:- Phloem transport distributes photoassimilates to the various sites of consumption and storage
-:- There are two modes of phloem loading
-:- Phloem transport proceeds by mass flow
-:- Sink tissues are supplied by phloem unloading
-:- Globulins are the most abundant storage proteins
-:- Prolamins are formed as storage proteins in grasses
-:- 2S-Proteins are present in seeds of dicot plants
-:- Special proteins protect seeds from being eaten by animals
-:- Synthesis of the storage proteins occurs at the rough endoplasmic reticulum
-:- Proteinases mobilize the amino acids deposited in storage proteins
-:- Lipids are membrane constituents and function as carbon stores
-:- Polar lipids are important membrane constituents
-:- Triacylglycerols are storage compounds
-:- The de novo synthesis of fatty acids takes place in the plastids
-:- Glycerol 3-phosphate is a precursor for the synthesis of glycerolipids
-:- Triacylglycerols are synthesized in the membranes of the endoplasmatic reticulum
-:- Storage lipids are mobilized for the production of carbohydrates in the glyoxysomes during seed germination
-:- Lipoxygenase is involved in the synthesis of oxylipins, which are defense and signal compounds
-:- Secondary metabolites often protect plants from pathogenic microorganisms and herbivores
-:- Alkaloids comprise a variety of heterocyclic secondary metabolites
-:- Some plants emit prussic acid when wounded by animals
-:- Some wounded plants emit volatile mustard oils
-:- Plants protect themselves by tricking herbivores with false amino acids
-:- A large diversity of isoprenoids has multiple functions in plant metabolism
-:- Higher plants have two different synthesis pathways for isoprenoids
-:- Prenyl transferases catalyze the association of isoprene units
-:- Some plants emit isoprenes into the air
-:- Many aromatic compounds derive from geranyl pyrophosphate
-:- Farnesyl pyrophosphate is the precursor for the synthesis of sesquiterpenes
-:- Geranylgeranyl pyrophosphate is the precursor for defense compounds, phytohormones, and carotenoids
-:- A Prenyl chain renders compounds lipid-soluble
-:- The regulation of isoprenoid synthesis
-:- Isoprenoids are very stable and persistent substances
-:- Phenylpropanoids comprise a multitude of plant secondary metabolites and cell wall components
-:- Phenylalanine ammonia lyase catalyzes the initial reaction of phenylpropanoid metabolism
-:- Monooxygenases are involved in the synthesis of phenols
-:- Phenylpropanoid compounds polymerize to macromolecules
-:- The synthesis of flavonoids and stilbenes requires a second aromatic ring derived from acetate residues
-:- Flavonoids have multiple functions in plants
-:- Anthocyanins are flower pigments and protect plants against excessive light
-:- Tannins bind tightly to proteins and therefore have defense functions
-:- Multiple signals regulate the growth and development of plant organs and enable their adaptation to environmental conditions
-:- Signal transduction chains known from animal metabolism also function in plants
-:- Phytohormones contain a variety of very different compounds
-:- Auxin stimulates shoot elongation growth
-:- Gibberellins regulate stem elongation
-:- Cytokinins stimulate cell division
-:- Abscisic acid controls the water balance of the plant
-:- Ethylene makes fruit ripen
-:- Plants also contain steroid and peptide hormones
-:- Defense reactions are triggered by the interplay of several signals
-:- Light sensors regulate growth and development of plants
-:- A plant cell has three different genomes
-:- In the nucleus the genetic information is divided among several chromosomes
-:- The DNA of the nuclear genome is transcribed by three specialized RNA polymerases
-:- DNA polymorphism yields genetic markers for plant breeding
-:- Transposable DNA elements roam through the genome
-:- Viruses are present in most plant cells
-:- Plastids possess a circular genome
-:- The mitochondrial genome of plants varies largely in its size
-:- Protein biosynthesis occurs in three different locations of a cell
-:- Protein synthesis is catalyzed by ribosomes
-:- Proteins attain their three-dimensional structure by controlled folding
-:- Nuclear encoded proteins are distributed throughout various cell compartments
-:- Proteins are degraded by proteasomes in a strictly controlled manner
-:- Biotechnology alters plants to meet requirements of agriculture, nutrition and industry
-:- A gene is isolated
-:- Agrobacteria can transform plant cells
-:- Ti-Plasmids are used as transformation vectors
-:- Selected promoters enable the defined expression of a foreign gene
-:- Genes can be turned off via plant transformation
-:- Plant genetic engineering can be used for many different purposes