symbiosis establisment between leguminous plant and rhizobacteria,cell morphogenesis and patterning,cell signaling,nod factor,leguminous plant,rhizobacteria,nitrogen fixation
The document summarizes key steps in nitrate assimilation by plants. It discusses how plants reduce nitrate to nitrite and then to ammonium within cells. The ammonium is assimilated through the glutamine synthetase/glutamate synthase pathway to produce glutamine and other organic nitrogen compounds. Biological nitrogen fixation by symbiotic bacteria is also summarized, including the signaling and nodulation processes that allow nitrogen-fixing bacteria to interact with plant hosts.
Co and post translationational modification of proteinsSukirti Vedula
This document discusses co-translational and post-translational modifications of proteins. It begins with an introduction to protein modification and defines co-translational and post-translational modifications. It then covers various co-translational modifications including regulation of translation, protein folding, and enzymes that catalyze protein folding. Post-translational modifications discussed include protein cleavage, glycosylation, addition of GPI anchors, ubiquitination, and phosphorylation. The document provides examples and details for many of the modification processes.
Bacillus anthracis produces three toxins - protective antigen (PA), lethal factor (LF), and edema factor (EF) - that are responsible for its virulence. PA binds to host cell receptors and forms a pore to transport EF and LF into the cell. Once inside, EF increases cyclic AMP levels through its calmodulin-dependent adenylate cyclase activity, causing edema. LF is a zinc-dependent metalloprotease that cleaves MAP kinase kinases, disrupting cell signaling and causing cell death. Together these toxins allow B. anthracis to evade the immune system and cause anthrax.
Signal transduction processes connected to the changes in cytosolic calcium c...Pradeep Singh Narwat
Calcium signalling occurs due to changes in cytosolic calcium concentration and activates protein kinase C. Protein kinase C is activated when phospholipase C breaks down phospholipids like phosphatidylinositol, producing diacylglycerol which remains in the cell membrane and recruits protein kinase C to the membrane. This allows calcium-calmodulin complexes to activate protein kinase C, leading to phosphorylation of transcription factors and regulation of processes like cell growth and metabolism. Phospholipase C also produces IP3 which triggers release of calcium from intracellular stores, further increasing cytosolic calcium levels.
1. INTRODUCTION
2. WHAT IS A RECEPTOR
3. HISTORY
4. CONCEPT OF CELL SIGNALLING
5. RECEPTOR SUPER FAMILIES
6. GPCRs- SIGNAL TRANSDUCTION & ITS SECOND MESSENGERS
JBEI Research Highlights - September 2018 Irina Silva
This document summarizes research on characterizing the activities of lignin-modifying enzymes using nanostructure-initiator mass spectrometry (NIMS). NIMS was used to rapidly analyze product formation and kinetics from reactions of a laccase and manganese peroxidase with phenolic and non-phenolic β-aryl ether model lignin substrates. Different primary reaction pathways were observed for each enzyme due to availability of phenoxy radical intermediates. NIMS provided quantitative analysis of bond cleavage events not available from conventional assays and can be performed in microliter volumes.
1. The document provides information about signal transduction in cells, including definitions of key terms like receptor, ligand, and pathways.
2. Receptors are transmembrane proteins that have domains on both sides of the membrane, and can be single or multiple transmembrane proteins. Ligands are molecules that bind to receptors and alter their function.
3. Signal transduction mechanisms include phosphorylation cascades where ligand binding causes receptor phosphorylation and activation of downstream kinases, and G protein activation where the receptor activates a G protein that then activates effector proteins.
The document summarizes key steps in nitrate assimilation by plants. It discusses how plants reduce nitrate to nitrite and then to ammonium within cells. The ammonium is assimilated through the glutamine synthetase/glutamate synthase pathway to produce glutamine and other organic nitrogen compounds. Biological nitrogen fixation by symbiotic bacteria is also summarized, including the signaling and nodulation processes that allow nitrogen-fixing bacteria to interact with plant hosts.
Co and post translationational modification of proteinsSukirti Vedula
This document discusses co-translational and post-translational modifications of proteins. It begins with an introduction to protein modification and defines co-translational and post-translational modifications. It then covers various co-translational modifications including regulation of translation, protein folding, and enzymes that catalyze protein folding. Post-translational modifications discussed include protein cleavage, glycosylation, addition of GPI anchors, ubiquitination, and phosphorylation. The document provides examples and details for many of the modification processes.
Bacillus anthracis produces three toxins - protective antigen (PA), lethal factor (LF), and edema factor (EF) - that are responsible for its virulence. PA binds to host cell receptors and forms a pore to transport EF and LF into the cell. Once inside, EF increases cyclic AMP levels through its calmodulin-dependent adenylate cyclase activity, causing edema. LF is a zinc-dependent metalloprotease that cleaves MAP kinase kinases, disrupting cell signaling and causing cell death. Together these toxins allow B. anthracis to evade the immune system and cause anthrax.
Signal transduction processes connected to the changes in cytosolic calcium c...Pradeep Singh Narwat
Calcium signalling occurs due to changes in cytosolic calcium concentration and activates protein kinase C. Protein kinase C is activated when phospholipase C breaks down phospholipids like phosphatidylinositol, producing diacylglycerol which remains in the cell membrane and recruits protein kinase C to the membrane. This allows calcium-calmodulin complexes to activate protein kinase C, leading to phosphorylation of transcription factors and regulation of processes like cell growth and metabolism. Phospholipase C also produces IP3 which triggers release of calcium from intracellular stores, further increasing cytosolic calcium levels.
1. INTRODUCTION
2. WHAT IS A RECEPTOR
3. HISTORY
4. CONCEPT OF CELL SIGNALLING
5. RECEPTOR SUPER FAMILIES
6. GPCRs- SIGNAL TRANSDUCTION & ITS SECOND MESSENGERS
JBEI Research Highlights - September 2018 Irina Silva
This document summarizes research on characterizing the activities of lignin-modifying enzymes using nanostructure-initiator mass spectrometry (NIMS). NIMS was used to rapidly analyze product formation and kinetics from reactions of a laccase and manganese peroxidase with phenolic and non-phenolic β-aryl ether model lignin substrates. Different primary reaction pathways were observed for each enzyme due to availability of phenoxy radical intermediates. NIMS provided quantitative analysis of bond cleavage events not available from conventional assays and can be performed in microliter volumes.
1. The document provides information about signal transduction in cells, including definitions of key terms like receptor, ligand, and pathways.
2. Receptors are transmembrane proteins that have domains on both sides of the membrane, and can be single or multiple transmembrane proteins. Ligands are molecules that bind to receptors and alter their function.
3. Signal transduction mechanisms include phosphorylation cascades where ligand binding causes receptor phosphorylation and activation of downstream kinases, and G protein activation where the receptor activates a G protein that then activates effector proteins.
Chronic granulomatous disease (CGD) results from defects in the NADPH oxidase system which generates reactive oxygen species to kill pathogens. There are several forms of CGD involving defects in different components of the NOX2 system. The majority of CGD cases involve mutations in the CYBB gene encoding the gp91-phox subunit of cytochrome b558. Other forms involve mutations in other genes encoding subunits of the NOX2 complex. Individuals with deficiencies in NADPH production can also exhibit similar symptoms to CGD.
The document discusses signal transduction, which is the process by which extracellular signals are converted into intracellular responses. There are six main steps: 1) synthesis and release of signaling molecules, 2) transport to target cell, 3) detection by receptor, 4) change in cell function triggered by receptor-signal complex, 5) removal of signal, and 6) termination of response. Signal transduction involves cell surface receptors and intracellular receptors that bind ligands and mediate specific cellular responses. Major types of signaling include endocrine, paracrine, and autocrine signaling.
JBEI Research Highlights - September 2018 Irina Silva
- Three members of the Arabidopsis thaliana glycosyltransferase family 92 (GALS1, GALS2, GALS3) were found to be β-1,4-galactan synthases that add galactose residues to the rhamnogalacturonan-I backbone.
- Overexpression of GALS proteins led to accumulation of unbranched β-1,4-galactan in Arabidopsis, while triple knockout mutants lacked detectable β-1,4-galactan but showed no developmental phenotypes.
- The study provides insight into the properties and roles of these galactan synthase enzymes in pectin biosynthesis in Arabidopsis.
Rho GTPases as regulators of morphological neuroplasticityFatih University
Rho GTPases play a key role in regulating neuronal morphology by mediating interactions between cell adhesion molecules and the cytoskeleton. Specifically, Rho inhibits neurite extension while Rac and Cdc42 promote neurite outgrowth and dendritic spine formation. In glial cells, Rho GTPases are involved in myelination by oligodendrocytes and Schwann cells. The role of RhoA in particular contributes to the inhibitory environment of the CNS that prevents axon regeneration.
This document summarizes different types of membrane proteins. It describes extrinsic (peripheral) proteins that bind weakly and reversibly to the membrane, as well as amphitropic proteins that change from a water-soluble to membrane-bound form. It also discusses intrinsic (integral) membrane proteins that are embedded in the membrane, including helical bundles and beta-barrel structures. Protein-lipid interactions and the effects of hydrophobic mismatch between proteins and lipids are also summarized.
This document provides an overview of the cell cycle, including mitosis, meiosis, regulation of cell replication, cyclins and CDKs, checkpoints, and signaling mechanisms. It discusses key events in the cell cycle such as cyclin D and RB phosphorylation, progression beyond the G1/S restriction point, and inhibitors. It also outlines different types of cellular receptors, including those with tyrosine kinase activity, those that recruit kinases, and seven transmembrane G-protein coupled receptors, and how they transmit signals via various pathways.
This document summarizes an evaluation seminar on cell signaling and signal transduction pathways presented by Mrutyunjay B Bellad of the Department of Pharmacology at H.S.K. College of Pharmacy in Bagalkot. The seminar covered various topics related to cell signaling including introduction, types of cell signaling, signal molecules and their actions, signaling through different receptor types, second messengers, G-protein coupled receptors, and signal transduction pathways. References included standard pharmacology textbooks.
This document provides an overview of bacterial genetics. It discusses the structure and function of bacterial genetic material, including DNA and RNA. It describes protein synthesis through transcription and translation. It also covers extrachromosomal genetic elements in bacteria, bacterial variation, mutation, and gene transfer. The key topics covered include the lac operon and its role in regulating lactose metabolism, different types of mutations and their effects, and the mechanisms of genetic variation and antibiotic resistance in bacteria.
This document discusses phospholipase C (PLC) and its role in neutrophil degranulation and T cell cytotoxicity. PLC hydrolyzes phosphatidylinositol 4,5-bisphosphate (PIP2) into two second messengers, diacylglycerol and inositol 1,4,5-trisphosphate. PLC signaling is required for lytic granule polarization and effective T cell killing through T cell antigen receptor activation. Neutrophil degranulation involves increases in calcium and PLC production of phosphatidylinositol, which is essential for granule exocytosis. Different intracellular signaling pathways regulate the release of primary, secondary, and tertiary granules from neutroph
Epidermal Growth Factor use in Diabetic Foot UlcersG H PRABHU
The document discusses epidermal growth factor (EGF) and EGF receptor (EGFR). It describes how Stanley Cohen discovered EGF in the 1950s while working with Rita Levi-Montalcini. It provides details on the structure and function of EGF, which is a 6045 Da protein, and EGFR. EGFR is a receptor tyrosine kinase that is activated upon binding of EGF or other ligands, leading to dimerization and autophosphorylation of tyrosine residues which propagate intracellular signaling cascades that influence cell proliferation, survival and other processes.
The forth lecture about the "Cell".
Here, I am discussing the several signaling pathways.....It is highly dependent on the 3rd lecture; Receptors.
Enjoy :)
RNA polymerase is the enzyme that controls transcription by unwinding DNA, building an RNA strand based on the DNA template, and proofreading as it adds nucleotides to improve accuracy. It makes an error about once per 10,000 nucleotides. Gene expression involves two main phases - transcription of DNA into mRNA and translation of mRNA into protein by ribosomes. Regulation of gene expression modulates these processes to control when genes are expressed. Post-translational modifications further process proteins after translation through additions like phosphorylation, glycosylation and lipidation that influence protein structure and function.
Dalton was an English chemist who developed Dalton's atomic theory which states that all matter is composed of extremely small indivisible particles called atoms and that atoms of a given element are identical in size, mass, and other properties. The document provides information on regulation of the RAG complex, mechanisms of PKCα and SGK in cell processes, defines autophagy and its mechanisms, steps in microautophagy and ubiquitination, and the chromosomal location of PTEN.
All living organisms must eventually deteriorate and die. Seeds being living entities also go through series of changes, leading to reduction in seed quality, performance and stand establishment before they finally loose viability. Soon after the physiological maturity, seeds enter the storage phase and are exposed to ageing. Seed deterioration involves almost every system with in the seed, many enzymes and apparently all organelles are affected. Seed deterioration can be defined as “deteriorative changes occurring with time that increase seed’s vulnerability to external challenges and decrease the ability of seed to survive.”
Reactive oxygen species and antioxidant system of mitochondria play important roles in seed biology. Seed aging may be due to the accumulation of reactive oxygen species (ROS) which causes lipid peroxidation, impairment of RNA and protein synthesis, and the degradation of DNA during storage.In developing or germinating seeds, major amounts of ROS are generated, which are highly toxic and thus generate oxidative stress in seed cells. Seeds have developed an array of defense strategies (antioxidant system) to cope up with oxidative stress. The scavenging of ROS largely depends on the availability of molecular antioxidants such as Superoxide dismutase, Catalase, Glutathione reductase, Ascorbate –Glutathion system.
Oxidative damage caused by free radicals/ROS
• ROS exert various effects on seed biology, depending on their concentration. Excessive accumulation of ROS disturbs the redox homeostasis of the cell and initiates oxidative stress, thus leading to a reduction in seed viability.
• Free radicals can react with one another and with non-free radicals to change the structure and function of other atoms and molecules. If these are proteins (enzymes), lipids (membranes) or nucleic acids (DNA) normal biological functions compromised and deterioration increases.
• ROS causes membrane lipid peroxidation and changes in the enzymatic antioxidant systems, as well as changes occur in the structure of the cell membrane.
• Lipid peroxidation: oxidative degradation of lipids.
• Involves initiation, propagation, termination
• Due to this oxidative damage inner mitochondrial membrane will be degraded
Antioxidant systems in seed
• Seeds contain a complex system of antioxidant defenses to protect against the harmful consequences of activated oxygen species
• Mitochondrial matrix contains ROS scavenging systems, systems such as
• Superoxide dismutase (SOD)
• Catalase ( CAT)
• Glutathione peroxidase and
• Ascorbate - glutathione (ASA-GSH) cycle.
mitochondrial basis of seed aging .pptxRanjithaJH2
All living organisms must eventually deteriorate and die
Seeds being living entities also go through series of changes, leading to reduction in seed quality, performance and stand establishment before they finally loose viability
Soon after the physiological maturity, seeds enter the storage phase and are exposed to ageing
Seed deterioration involves almost every system in the seed. Almost all enzymes and organelles are affected
It is a complex process associated with numerous physiological alterations including lipid peroxidation, membrane disruption, DNA damage and impairment of protein synthesis.
Mitochondrial Functions :) Essential for aerobic metabolism.
b) Energy production through oxidative phosphorylation.
c) ATP producing power house of cell.
d) Involved in metabolic pathways:
1.Glycolysis
2.Krebs cycle
3.ETC
4.Oxidative phosphorylation
e)Maintain, replicate & transcribe their own DNA.
f) Production of free radicles or reactive oxygen species.
Mitochondrial activity in seed ageing:Generation of ROS mainly takes place at electron transport chain located on inner mitochondrial membrane during the process of oxidative phosphorylation.
Examples of ROS ; super oxide anion (O•2- )
hydrogen peroxide (H2O2)
hydroxyl radicles (•OH- )
The main theory of aging is the ‘free radical theory’ proposed by Harman (2006).
“It postulates that accumulation of free radicals in the cell is the underlying mechanism of aging in all living organisms”
Free radicals are the molecules that contain one or more unpaired electron in their outer orbit since these are formed from oxygen they are called ROS
Characteristics of ROS
Extremely reactive
Short life span
Generation of new ROS by chain reaction
Causes damage to various tissues
Oxidative damage caused by free radicals/ROS:ROS exert various effects on seed biology, depending on their concentration. Excessive accumulation of ROS disturbs the redox homeostasis of the cell and initiates oxidative stress, thus leading to a reduction in seed viability.
Free radicals can react with one another and with non-free radicals to change the structure and function of other atoms and molecules. If these are proteins (enzymes), lipids (membranes) or nucleic acids (DNA) normal biological functions compromised and deterioration increases.
ROS causes membrane lipid peroxidation and changes in the enzymatic antioxidant systems, as well as changes occur in the structure of the cell membrane.
Lipid peroxidation: oxidative degradation of lipids.
Involves initiation, propagation, termination
Due to this oxidative damage inner mitochondrial membrane will be degraded
Seeds contain a complex system of antioxidant defenses to protect against the harmful consequences of activated oxygen species
Mitochondrial matrix contains ROS scavenging systems, system
Post-translational modifications are important biochemical mechanisms that regulate protein function. Common types of post-translational modifications include phosphorylation, hydroxylation, glycosylation, and methylation. These modifications occur on amino acid side chains or termini and are catalyzed by specific enzymes. For example, phosphorylation regulates enzyme activity, while hydroxylation and glycosylation of amino acids are required for collagen assembly and function. Overall, post-translational modifications expand the functional diversity of the proteome.
This document discusses receptor and signal transduction mechanisms. It begins by defining receptors as proteins that bind hormones, neurotransmitters, and other chemicals with specificity and affinity to produce cellular responses. It then describes the main functions of receptors. The document outlines the major categories of signal transduction mechanisms: ion channel linked, G protein coupled, enzyme linked, JAK-STAT binding, and nuclear receptors. For each category, it provides examples and describes the basic process of signal propagation and cellular response. In summary, it provides an overview of receptor types and the main pathways of signal transduction in cells.
Marine ecology emphasizes the relationships between organisms and their ocean environment. The sea covers 70% of the Earth's surface and connects all oceans. Temperature, salinity, and depth create barriers for marine organisms. The sea is dominated by waves and tides from the moon and sun. It is salty, with an average salinity of 3.5%. Dissolved nutrients are in low concentrations, limiting marine populations. Marine environments show great diversity, including algae, sponges, corals, mollusks, crustaceans, and fish. Communities exist in coastal shelves, intertidal zones, and open ocean areas. Producers include phytoplankton and seaweeds, while consumers comprise z
More Related Content
Similar to symbiosis establisment between leguminous plant and rhizobacteria
Chronic granulomatous disease (CGD) results from defects in the NADPH oxidase system which generates reactive oxygen species to kill pathogens. There are several forms of CGD involving defects in different components of the NOX2 system. The majority of CGD cases involve mutations in the CYBB gene encoding the gp91-phox subunit of cytochrome b558. Other forms involve mutations in other genes encoding subunits of the NOX2 complex. Individuals with deficiencies in NADPH production can also exhibit similar symptoms to CGD.
The document discusses signal transduction, which is the process by which extracellular signals are converted into intracellular responses. There are six main steps: 1) synthesis and release of signaling molecules, 2) transport to target cell, 3) detection by receptor, 4) change in cell function triggered by receptor-signal complex, 5) removal of signal, and 6) termination of response. Signal transduction involves cell surface receptors and intracellular receptors that bind ligands and mediate specific cellular responses. Major types of signaling include endocrine, paracrine, and autocrine signaling.
JBEI Research Highlights - September 2018 Irina Silva
- Three members of the Arabidopsis thaliana glycosyltransferase family 92 (GALS1, GALS2, GALS3) were found to be β-1,4-galactan synthases that add galactose residues to the rhamnogalacturonan-I backbone.
- Overexpression of GALS proteins led to accumulation of unbranched β-1,4-galactan in Arabidopsis, while triple knockout mutants lacked detectable β-1,4-galactan but showed no developmental phenotypes.
- The study provides insight into the properties and roles of these galactan synthase enzymes in pectin biosynthesis in Arabidopsis.
Rho GTPases as regulators of morphological neuroplasticityFatih University
Rho GTPases play a key role in regulating neuronal morphology by mediating interactions between cell adhesion molecules and the cytoskeleton. Specifically, Rho inhibits neurite extension while Rac and Cdc42 promote neurite outgrowth and dendritic spine formation. In glial cells, Rho GTPases are involved in myelination by oligodendrocytes and Schwann cells. The role of RhoA in particular contributes to the inhibitory environment of the CNS that prevents axon regeneration.
This document summarizes different types of membrane proteins. It describes extrinsic (peripheral) proteins that bind weakly and reversibly to the membrane, as well as amphitropic proteins that change from a water-soluble to membrane-bound form. It also discusses intrinsic (integral) membrane proteins that are embedded in the membrane, including helical bundles and beta-barrel structures. Protein-lipid interactions and the effects of hydrophobic mismatch between proteins and lipids are also summarized.
This document provides an overview of the cell cycle, including mitosis, meiosis, regulation of cell replication, cyclins and CDKs, checkpoints, and signaling mechanisms. It discusses key events in the cell cycle such as cyclin D and RB phosphorylation, progression beyond the G1/S restriction point, and inhibitors. It also outlines different types of cellular receptors, including those with tyrosine kinase activity, those that recruit kinases, and seven transmembrane G-protein coupled receptors, and how they transmit signals via various pathways.
This document summarizes an evaluation seminar on cell signaling and signal transduction pathways presented by Mrutyunjay B Bellad of the Department of Pharmacology at H.S.K. College of Pharmacy in Bagalkot. The seminar covered various topics related to cell signaling including introduction, types of cell signaling, signal molecules and their actions, signaling through different receptor types, second messengers, G-protein coupled receptors, and signal transduction pathways. References included standard pharmacology textbooks.
This document provides an overview of bacterial genetics. It discusses the structure and function of bacterial genetic material, including DNA and RNA. It describes protein synthesis through transcription and translation. It also covers extrachromosomal genetic elements in bacteria, bacterial variation, mutation, and gene transfer. The key topics covered include the lac operon and its role in regulating lactose metabolism, different types of mutations and their effects, and the mechanisms of genetic variation and antibiotic resistance in bacteria.
This document discusses phospholipase C (PLC) and its role in neutrophil degranulation and T cell cytotoxicity. PLC hydrolyzes phosphatidylinositol 4,5-bisphosphate (PIP2) into two second messengers, diacylglycerol and inositol 1,4,5-trisphosphate. PLC signaling is required for lytic granule polarization and effective T cell killing through T cell antigen receptor activation. Neutrophil degranulation involves increases in calcium and PLC production of phosphatidylinositol, which is essential for granule exocytosis. Different intracellular signaling pathways regulate the release of primary, secondary, and tertiary granules from neutroph
Epidermal Growth Factor use in Diabetic Foot UlcersG H PRABHU
The document discusses epidermal growth factor (EGF) and EGF receptor (EGFR). It describes how Stanley Cohen discovered EGF in the 1950s while working with Rita Levi-Montalcini. It provides details on the structure and function of EGF, which is a 6045 Da protein, and EGFR. EGFR is a receptor tyrosine kinase that is activated upon binding of EGF or other ligands, leading to dimerization and autophosphorylation of tyrosine residues which propagate intracellular signaling cascades that influence cell proliferation, survival and other processes.
The forth lecture about the "Cell".
Here, I am discussing the several signaling pathways.....It is highly dependent on the 3rd lecture; Receptors.
Enjoy :)
RNA polymerase is the enzyme that controls transcription by unwinding DNA, building an RNA strand based on the DNA template, and proofreading as it adds nucleotides to improve accuracy. It makes an error about once per 10,000 nucleotides. Gene expression involves two main phases - transcription of DNA into mRNA and translation of mRNA into protein by ribosomes. Regulation of gene expression modulates these processes to control when genes are expressed. Post-translational modifications further process proteins after translation through additions like phosphorylation, glycosylation and lipidation that influence protein structure and function.
Dalton was an English chemist who developed Dalton's atomic theory which states that all matter is composed of extremely small indivisible particles called atoms and that atoms of a given element are identical in size, mass, and other properties. The document provides information on regulation of the RAG complex, mechanisms of PKCα and SGK in cell processes, defines autophagy and its mechanisms, steps in microautophagy and ubiquitination, and the chromosomal location of PTEN.
All living organisms must eventually deteriorate and die. Seeds being living entities also go through series of changes, leading to reduction in seed quality, performance and stand establishment before they finally loose viability. Soon after the physiological maturity, seeds enter the storage phase and are exposed to ageing. Seed deterioration involves almost every system with in the seed, many enzymes and apparently all organelles are affected. Seed deterioration can be defined as “deteriorative changes occurring with time that increase seed’s vulnerability to external challenges and decrease the ability of seed to survive.”
Reactive oxygen species and antioxidant system of mitochondria play important roles in seed biology. Seed aging may be due to the accumulation of reactive oxygen species (ROS) which causes lipid peroxidation, impairment of RNA and protein synthesis, and the degradation of DNA during storage.In developing or germinating seeds, major amounts of ROS are generated, which are highly toxic and thus generate oxidative stress in seed cells. Seeds have developed an array of defense strategies (antioxidant system) to cope up with oxidative stress. The scavenging of ROS largely depends on the availability of molecular antioxidants such as Superoxide dismutase, Catalase, Glutathione reductase, Ascorbate –Glutathion system.
Oxidative damage caused by free radicals/ROS
• ROS exert various effects on seed biology, depending on their concentration. Excessive accumulation of ROS disturbs the redox homeostasis of the cell and initiates oxidative stress, thus leading to a reduction in seed viability.
• Free radicals can react with one another and with non-free radicals to change the structure and function of other atoms and molecules. If these are proteins (enzymes), lipids (membranes) or nucleic acids (DNA) normal biological functions compromised and deterioration increases.
• ROS causes membrane lipid peroxidation and changes in the enzymatic antioxidant systems, as well as changes occur in the structure of the cell membrane.
• Lipid peroxidation: oxidative degradation of lipids.
• Involves initiation, propagation, termination
• Due to this oxidative damage inner mitochondrial membrane will be degraded
Antioxidant systems in seed
• Seeds contain a complex system of antioxidant defenses to protect against the harmful consequences of activated oxygen species
• Mitochondrial matrix contains ROS scavenging systems, systems such as
• Superoxide dismutase (SOD)
• Catalase ( CAT)
• Glutathione peroxidase and
• Ascorbate - glutathione (ASA-GSH) cycle.
mitochondrial basis of seed aging .pptxRanjithaJH2
All living organisms must eventually deteriorate and die
Seeds being living entities also go through series of changes, leading to reduction in seed quality, performance and stand establishment before they finally loose viability
Soon after the physiological maturity, seeds enter the storage phase and are exposed to ageing
Seed deterioration involves almost every system in the seed. Almost all enzymes and organelles are affected
It is a complex process associated with numerous physiological alterations including lipid peroxidation, membrane disruption, DNA damage and impairment of protein synthesis.
Mitochondrial Functions :) Essential for aerobic metabolism.
b) Energy production through oxidative phosphorylation.
c) ATP producing power house of cell.
d) Involved in metabolic pathways:
1.Glycolysis
2.Krebs cycle
3.ETC
4.Oxidative phosphorylation
e)Maintain, replicate & transcribe their own DNA.
f) Production of free radicles or reactive oxygen species.
Mitochondrial activity in seed ageing:Generation of ROS mainly takes place at electron transport chain located on inner mitochondrial membrane during the process of oxidative phosphorylation.
Examples of ROS ; super oxide anion (O•2- )
hydrogen peroxide (H2O2)
hydroxyl radicles (•OH- )
The main theory of aging is the ‘free radical theory’ proposed by Harman (2006).
“It postulates that accumulation of free radicals in the cell is the underlying mechanism of aging in all living organisms”
Free radicals are the molecules that contain one or more unpaired electron in their outer orbit since these are formed from oxygen they are called ROS
Characteristics of ROS
Extremely reactive
Short life span
Generation of new ROS by chain reaction
Causes damage to various tissues
Oxidative damage caused by free radicals/ROS:ROS exert various effects on seed biology, depending on their concentration. Excessive accumulation of ROS disturbs the redox homeostasis of the cell and initiates oxidative stress, thus leading to a reduction in seed viability.
Free radicals can react with one another and with non-free radicals to change the structure and function of other atoms and molecules. If these are proteins (enzymes), lipids (membranes) or nucleic acids (DNA) normal biological functions compromised and deterioration increases.
ROS causes membrane lipid peroxidation and changes in the enzymatic antioxidant systems, as well as changes occur in the structure of the cell membrane.
Lipid peroxidation: oxidative degradation of lipids.
Involves initiation, propagation, termination
Due to this oxidative damage inner mitochondrial membrane will be degraded
Seeds contain a complex system of antioxidant defenses to protect against the harmful consequences of activated oxygen species
Mitochondrial matrix contains ROS scavenging systems, system
Post-translational modifications are important biochemical mechanisms that regulate protein function. Common types of post-translational modifications include phosphorylation, hydroxylation, glycosylation, and methylation. These modifications occur on amino acid side chains or termini and are catalyzed by specific enzymes. For example, phosphorylation regulates enzyme activity, while hydroxylation and glycosylation of amino acids are required for collagen assembly and function. Overall, post-translational modifications expand the functional diversity of the proteome.
This document discusses receptor and signal transduction mechanisms. It begins by defining receptors as proteins that bind hormones, neurotransmitters, and other chemicals with specificity and affinity to produce cellular responses. It then describes the main functions of receptors. The document outlines the major categories of signal transduction mechanisms: ion channel linked, G protein coupled, enzyme linked, JAK-STAT binding, and nuclear receptors. For each category, it provides examples and describes the basic process of signal propagation and cellular response. In summary, it provides an overview of receptor types and the main pathways of signal transduction in cells.
Similar to symbiosis establisment between leguminous plant and rhizobacteria (20)
Marine ecology emphasizes the relationships between organisms and their ocean environment. The sea covers 70% of the Earth's surface and connects all oceans. Temperature, salinity, and depth create barriers for marine organisms. The sea is dominated by waves and tides from the moon and sun. It is salty, with an average salinity of 3.5%. Dissolved nutrients are in low concentrations, limiting marine populations. Marine environments show great diversity, including algae, sponges, corals, mollusks, crustaceans, and fish. Communities exist in coastal shelves, intertidal zones, and open ocean areas. Producers include phytoplankton and seaweeds, while consumers comprise z
Interspecific association refers to direct and indirect interactions between species. There are three main types of interspecific interactions: positive, negative, and neutral. Positive interactions include mutualism, where both species benefit, and commensalism where one benefits and the other is unaffected. Negative interactions include predation, parasitism, competition, and ammensalism. Predation involves a predator species harming prey species. Parasitism involves a parasitic species benefiting at the expense of a host species. Competition involves species decreasing each other's chances of survival by competing for resources.
Ecological succession is the gradual replacement of one community by another until a stable climax community is established. The document describes the process of ecological succession, including primary and secondary succession. It provides examples of hydrosere succession, which begins in a body of water and progresses through stages from phytoplankton to forest. The stages include submerged plants, floating plants, reed swamp, sedge meadow, woodland, and climax forest community as the habitat becomes increasingly dry over time due to soil accumulation.
Global climate change refers to long-term shifts in weather patterns due to both natural causes like volcanic eruptions and human activities such as burning fossil fuels. The greenhouse effect traps heat in the lower atmosphere due to greenhouse gases like carbon dioxide and methane, resulting in global warming and rising global temperatures over recent decades. Effects of climate change include rising sea levels, more extreme weather events, melting glaciers and ice sheets, and threats to human health, agriculture, and ecosystems. Strategies to address climate change focus on reducing greenhouse gas emissions through alternatives to fossil fuels, conservation efforts, and preparing for inevitable impacts.
This document discusses energy plantations for ethanol and biodiesel production. It begins by introducing that sugarcane, sweet sorghum, and sugar beet are used to produce ethanol through fermentation of their sugars. Starch from crops like maize and wheat can also be converted to sugar for ethanol production. The document then discusses advantages like renewability and lower emissions of ethanol fuel. It notes India's aim to increase ethanol blending in gasoline. Methods of biodiesel production through transesterification of oils are outlined. Challenges of ethanol and biodiesel like land use and affordability are also summarized.
Male sterility refers to a plant's failure to produce functional anthers, pollen, or male gametes. It most commonly occurs in bisexual flowers. There are several types of male sterility, including genetic male sterility which is controlled by recessive alleles, non-genetic male sterility caused by environmental factors, and cytoplasmic male sterility resulting from mutations in mitochondrial DNA. Male sterile plants are useful for hybrid seed production as they can be used as the female parent in cross-breeding without the need for emasculation, saving time, labor, and money.
UV-visible spectroscopy involves using electromagnetic radiation in the ultraviolet-visible spectral region to analyze chemical substances. It operates based on the principle that molecules absorb specific wavelengths of UV or visible light. The absorbed wavelengths are characteristic of a molecule's chemical structure. A spectrophotometer directs a beam of light through the sample solution and measures the light absorption. UV-visible spectroscopy is useful for identifying organic compounds, detecting impurities, and quantitative analysis according to Beer's law. It has advantages of simple instrumentation and applicability to many organic molecules, but limitations include spectral overlap from mixtures and dependence on solution conditions.
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Compositions of iron-meteorite parent bodies constrainthe structure of the pr...Sérgio Sacani
Magmatic iron-meteorite parent bodies are the earliest planetesimals in the Solar System,and they preserve information about conditions and planet-forming processes in thesolar nebula. In this study, we include comprehensive elemental compositions andfractional-crystallization modeling for iron meteorites from the cores of five differenti-ated asteroids from the inner Solar System. Together with previous results of metalliccores from the outer Solar System, we conclude that asteroidal cores from the outerSolar System have smaller sizes, elevated siderophile-element abundances, and simplercrystallization processes than those from the inner Solar System. These differences arerelated to the formation locations of the parent asteroids because the solar protoplane-tary disk varied in redox conditions, elemental distributions, and dynamics at differentheliocentric distances. Using highly siderophile-element data from iron meteorites, wereconstruct the distribution of calcium-aluminum-rich inclusions (CAIs) across theprotoplanetary disk within the first million years of Solar-System history. CAIs, the firstsolids to condense in the Solar System, formed close to the Sun. They were, however,concentrated within the outer disk and depleted within the inner disk. Future modelsof the structure and evolution of the protoplanetary disk should account for this dis-tribution pattern of CAIs.
Evidence of Jet Activity from the Secondary Black Hole in the OJ 287 Binary S...Sérgio Sacani
Wereport the study of a huge optical intraday flare on 2021 November 12 at 2 a.m. UT in the blazar OJ287. In the binary black hole model, it is associated with an impact of the secondary black hole on the accretion disk of the primary. Our multifrequency observing campaign was set up to search for such a signature of the impact based on a prediction made 8 yr earlier. The first I-band results of the flare have already been reported by Kishore et al. (2024). Here we combine these data with our monitoring in the R-band. There is a big change in the R–I spectral index by 1.0 ±0.1 between the normal background and the flare, suggesting a new component of radiation. The polarization variation during the rise of the flare suggests the same. The limits on the source size place it most reasonably in the jet of the secondary BH. We then ask why we have not seen this phenomenon before. We show that OJ287 was never before observed with sufficient sensitivity on the night when the flare should have happened according to the binary model. We also study the probability that this flare is just an oversized example of intraday variability using the Krakow data set of intense monitoring between 2015 and 2023. We find that the occurrence of a flare of this size and rapidity is unlikely. In machine-readable Tables 1 and 2, we give the full orbit-linked historical light curve of OJ287 as well as the dense monitoring sample of Krakow.
Anti-Universe And Emergent Gravity and the Dark UniverseSérgio Sacani
Recent theoretical progress indicates that spacetime and gravity emerge together from the entanglement structure of an underlying microscopic theory. These ideas are best understood in Anti-de Sitter space, where they rely on the area law for entanglement entropy. The extension to de Sitter space requires taking into account the entropy and temperature associated with the cosmological horizon. Using insights from string theory, black hole physics and quantum information theory we argue that the positive dark energy leads to a thermal volume law contribution to the entropy that overtakes the area law precisely at the cosmological horizon. Due to the competition between area and volume law entanglement the microscopic de Sitter states do not thermalise at sub-Hubble scales: they exhibit memory effects in the form of an entropy displacement caused by matter. The emergent laws of gravity contain an additional ‘dark’ gravitational force describing the ‘elastic’ response due to the entropy displacement. We derive an estimate of the strength of this extra force in terms of the baryonic mass, Newton’s constant and the Hubble acceleration scale a0 = cH0, and provide evidence for the fact that this additional ‘dark gravity force’ explains the observed phenomena in galaxies and clusters currently attributed to dark matter.
JAMES WEBB STUDY THE MASSIVE BLACK HOLE SEEDSSérgio Sacani
The pathway(s) to seeding the massive black holes (MBHs) that exist at the heart of galaxies in the present and distant Universe remains an unsolved problem. Here we categorise, describe and quantitatively discuss the formation pathways of both light and heavy seeds. We emphasise that the most recent computational models suggest that rather than a bimodal-like mass spectrum between light and heavy seeds with light at one end and heavy at the other that instead a continuum exists. Light seeds being more ubiquitous and the heavier seeds becoming less and less abundant due the rarer environmental conditions required for their formation. We therefore examine the different mechanisms that give rise to different seed mass spectrums. We show how and why the mechanisms that produce the heaviest seeds are also among the rarest events in the Universe and are hence extremely unlikely to be the seeds for the vast majority of the MBH population. We quantify, within the limits of the current large uncertainties in the seeding processes, the expected number densities of the seed mass spectrum. We argue that light seeds must be at least 103 to 105 times more numerous than heavy seeds to explain the MBH population as a whole. Based on our current understanding of the seed population this makes heavy seeds (Mseed > 103 M⊙) a significantly more likely pathway given that heavy seeds have an abundance pattern than is close to and likely in excess of 10−4 compared to light seeds. Finally, we examine the current state-of-the-art in numerical calculations and recent observations and plot a path forward for near-future advances in both domains.
Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...Sérgio Sacani
Context. The observation of several L-band emission sources in the S cluster has led to a rich discussion of their nature. However, a definitive answer to the classification of the dusty objects requires an explanation for the detection of compact Doppler-shifted Brγ emission. The ionized hydrogen in combination with the observation of mid-infrared L-band continuum emission suggests that most of these sources are embedded in a dusty envelope. These embedded sources are part of the S-cluster, and their relationship to the S-stars is still under debate. To date, the question of the origin of these two populations has been vague, although all explanations favor migration processes for the individual cluster members. Aims. This work revisits the S-cluster and its dusty members orbiting the supermassive black hole SgrA* on bound Keplerian orbits from a kinematic perspective. The aim is to explore the Keplerian parameters for patterns that might imply a nonrandom distribution of the sample. Additionally, various analytical aspects are considered to address the nature of the dusty sources. Methods. Based on the photometric analysis, we estimated the individual H−K and K−L colors for the source sample and compared the results to known cluster members. The classification revealed a noticeable contrast between the S-stars and the dusty sources. To fit the flux-density distribution, we utilized the radiative transfer code HYPERION and implemented a young stellar object Class I model. We obtained the position angle from the Keplerian fit results; additionally, we analyzed the distribution of the inclinations and the longitudes of the ascending node. Results. The colors of the dusty sources suggest a stellar nature consistent with the spectral energy distribution in the near and midinfrared domains. Furthermore, the evaporation timescales of dusty and gaseous clumps in the vicinity of SgrA* are much shorter ( 2yr) than the epochs covered by the observations (≈15yr). In addition to the strong evidence for the stellar classification of the D-sources, we also find a clear disk-like pattern following the arrangements of S-stars proposed in the literature. Furthermore, we find a global intrinsic inclination for all dusty sources of 60 ± 20◦, implying a common formation process. Conclusions. The pattern of the dusty sources manifested in the distribution of the position angles, inclinations, and longitudes of the ascending node strongly suggests two different scenarios: the main-sequence stars and the dusty stellar S-cluster sources share a common formation history or migrated with a similar formation channel in the vicinity of SgrA*. Alternatively, the gravitational influence of SgrA* in combination with a massive perturber, such as a putative intermediate mass black hole in the IRS 13 cluster, forces the dusty objects and S-stars to follow a particular orbital arrangement. Key words. stars: black holes– stars: formation– Galaxy: center– galaxies: star formation
Mechanisms and Applications of Antiviral Neutralizing Antibodies - Creative B...Creative-Biolabs
Neutralizing antibodies, pivotal in immune defense, specifically bind and inhibit viral pathogens, thereby playing a crucial role in protecting against and mitigating infectious diseases. In this slide, we will introduce what antibodies and neutralizing antibodies are, the production and regulation of neutralizing antibodies, their mechanisms of action, classification and applications, as well as the challenges they face.
Mechanisms and Applications of Antiviral Neutralizing Antibodies - Creative B...
symbiosis establisment between leguminous plant and rhizobacteria
1. Signaling in bacteria and legumionus
plants during nitrogen fixation
,signaling during cell morphogenesis
and patterning
Submitted to:- submitted by:-
Dr.ashun sir UDAYPAL
CUHP20PLS30
2. NITROGENESE COMPLEX ENZYME
REDUCTASE NITROGENESE
Small componant Large componant
Contain Fe protein Contain Fe,Mo protein
Homodiemer tetramar
Consist two types of enzymes
3. • 8 H+ + 8 e- + N2 + 16 ATP → 2NH3 + 16 ADP + 16 Pi
Reductase cause reduction in nitrogenese transfer
electron Fd to P-cluster and than P-cluster to Fe-Mo
cluster
Nitrogenese cause reduction in nitrogen and convert into
NH3
Reductase require 2ATP for transfer of one electron
Total 16ATP require for formation of 2 NH3 from N2
4. ROOT NODULE FORMATION
• When plant face nitrogen deficiency release some
chemicals Flavinoids Isoflavinoids these chemicals
arttract bacteria
• Bacteria attach to root hair and root hair start curling
• Bacteria digest root cell wall and form infection tube
• Golgi vesicles form infection tube by fusing together
• Bacteria enter in cortex through infection tube and
cortex cell start divide and form nodule
• Nodule contain high amount of bacteria that fix
nitrogen
5. PLANT GENES RHIZOBIAL GENES
Called Nodulin (Nod) genes Called Nodulation(nod ) genes
Nodulation genes classified in two groups:-
COMMON GENES HOST SPECIFIC GENES
nodA ,nodB,and nodC (Present in all
rhizobia)
nodE,nodF,nodH,nodL,nodP,nodQ(found
only in specific species)
Product of common genes require for
synthesis of nod factor
Product of these gens reuire for chemical
modification of nod factor
Nod factor:-
It is a lipo-chitin-oligosaccharide syntyesized by
symbiotic bacteria in response of nodulation signal
In Nod factor sugar residue linked by beta 1-4 Glycosidic bond
Fatty acid (16-18c)long present on 2nd postion of non-reducing
sugar end
6. ENZYME Gene FUNCTION
Acyl-transferase nodA Catalyse addition of fatty
acid
Deacetylase nodB Remove acyl groups
Chitin-synthatase nodC Catalyse synthesis of
chitin
NodE,NodF Determine the length and degree of
saturation of fatty acyl-chain
NodL Add or remove specific group on Nod-
factor
7. Nod-factor function
1.Act as a signal for symbiosis 2.Induce curling in root hair
3.Induce expression of Noduline genes 4.Trigger cell divisine in plant
8. • Nod factor bind with receptor of root hair cell
and increase calcium level in cell by IP3-DAG
pathway
• High calcium activate Nod sensitive
transcription factor(GRAR,ERF) that trigger
expression of nodulin genes and establish
symbiosis
EXPRESSION OF COMMON AND HOST SPECIFIC
GENES:-
When bacteria present in free soil then it not secrete Nod factor
But when it get signal then it start Nod factor formation (in
response of falvinoids )
Flavinoids bind with NodD protein expression of NodD genes is
constitutive
9. NodD protein is a transcription factor that bind with Nod box and
induce expression of common and host specific genes
Exprssion of common and host specific genes is inducible
10. Signaling during cell morphogenesis
and patterning
• Non-canonical Pathway(beta-cat independent):-
require for cell shape change ,cell
morphogenesis ,cell mortility or ca+2 release
after dovelopment of cell
(1)PATHWAY-1:-
wnt bind with frizzled receptor Ryk and
Ror act as a co-receptor that activate Rho-GTPase
and start cytoskeleton recognization and change cell
shape and behavior
11.
12. (1)PATHWAY-2:-
wnt bind with frizzled receptor and
Disheveled bind with inner side of frizzled receptor.
Disheveled activate Rho-GTPase(Daam1 mediates
activation) that cause cytoskeleton recognization or
Gene expression that change cell behaviour and
shape
Daam1 also mediates actin polymerization through the
actin binding protein Profilin(require for monomer
assembly of actin fillament)
Actin form a network through cytoplasam that provide
structural framework for cell shape ,position of
orgenelles,organization of cytoskeleton
13. (3)PATHWAY-3:-
Wnt bind with frizzled receptor that break PIP2 into
IP3and DAG
IP3 open calcium chennal or ER and release calcium from ER
Concentration of cytosolic calcium increase that act as a secondry
messenger and activate PKC(protein kinase –c)
PKC activate transcription factors by phosphorylation and start
transcription and provide structural framework to cell and cell shape
(4)PATHWAY-4:-
Wnt bind with Ryk/Ror receptor that directly
open calcium chennal of ER and increase cytosolic calcium
level
Calcium act as a secondry messenger and activate PKC that
activate transcription factors by phosphorylation and induce
cell shape and function change