A non-covalent interaction differs from a covalent bond in that it does not involve the sharing of electrons, but rather involves more dispersed variations of electromagnetic interactions between molecules or within a molecule.
1. Covalent and non-covalent interactions are important for macromolecule structure and function. Covalent bonds strongly bind atomic subunits while non-covalent bonds like hydrogen bonding and hydrophobic interactions more weakly stabilize macromolecule structures.
2. Covalent bonds like peptide bonds link amino acids into protein chains. Non-covalent interactions are crucial for protein folding and binding specificity. Though individually weak, many non-covalent bonds cooperatively bind molecular surfaces.
3. Covalent drugs form irreversible complexes with target proteins, while non-covalent drugs reversibly inhibit enzymes through competitive, noncompetitive, or uncompetitive binding. Examples are covalent penicillin and non-covalent acetylcholinester
Covalent bonds, peptide bonds, and disulfide bridges stabilize protein structures through strong covalent interactions. Non-covalent interactions like van der Waals forces, hydrogen bonds, electrostatic interactions, and hydrophobic effects also contribute to protein stability. These non-covalent interactions are weaker than covalent bonds but work together in large numbers to stabilize a protein's native conformation. Perturbations can disrupt this delicate balance of interactions and cause protein denaturation.
This document discusses various types of non-covalent interactions including van der Waals forces, hydrogen bonding, electrostatic interactions, and hydrophobic interactions. It provides details on the relative strengths of each interaction and their importance in maintaining the structure of biological molecules like proteins and nucleic acids. Specific examples highlighted include hydrogen bonding holding together the DNA double helix and hydrophobic interactions driving the association of nonpolar molecules in aqueous solutions.
The document discusses hydrophobic interactions and effects. It defines hydrophobicity as molecules that do not interact well with water, such as nonpolar substances. When these molecules are introduced into water, they aggregate together to minimize contact with water molecules. This occurs because breaking hydrogen bonds between water and the hydrophobic molecules is entropically unfavorable. The hydrophobic effect is driven by this entropy change and causes nonpolar substances to cluster together in aqueous solutions.
Secondary Structure Of Protein (Repeating structure of protein)Amrutha Hari
This document discusses the structure of proteins at various levels. It describes the primary, secondary, tertiary, and quaternary structures. The secondary structures discussed in detail include the alpha helix, beta pleated sheet, random coil, collagen helix, and beta turn. The alpha helix and beta pleated sheet are stabilized by hydrogen bonding between amino acids. The collagen helix structure provides strength and is the main component of connective tissues. Genetic disorders like Ehlers-Danlos syndrome and osteogenesis imperfecta result from defects in collagen structures. Ramachandran plots are used to visualize allowed backbone dihedral angles in protein structures.
The document summarizes the mechanisms of enzyme catalysis. It discusses how enzymes lower the activation energy of reactions by releasing binding energy when interacting with substrates. This allows enzymes to accelerate reactions by stabilizing transition states. There are three main types of catalytic mechanisms: acid-base catalysis, covalent catalysis, and metal ion catalysis. Acid-base catalysis involves proton transfers. Covalent catalysis forms temporary covalent bonds between enzymes and substrates. Metal ion catalysis uses metal ions like iron and copper to orient and stabilize reactive molecules in enzyme active sites.
A membrane protein is a protein molecule that is attached to, or associated with the membrane of a cell or an organelle.
More than half of all proteins interact with membranes.
I have tried to make a precise presentation on protein transport, targeting and sorting into organelle's other than nucleus. Hope this might help you. Comments are welcome.
1. Covalent and non-covalent interactions are important for macromolecule structure and function. Covalent bonds strongly bind atomic subunits while non-covalent bonds like hydrogen bonding and hydrophobic interactions more weakly stabilize macromolecule structures.
2. Covalent bonds like peptide bonds link amino acids into protein chains. Non-covalent interactions are crucial for protein folding and binding specificity. Though individually weak, many non-covalent bonds cooperatively bind molecular surfaces.
3. Covalent drugs form irreversible complexes with target proteins, while non-covalent drugs reversibly inhibit enzymes through competitive, noncompetitive, or uncompetitive binding. Examples are covalent penicillin and non-covalent acetylcholinester
Covalent bonds, peptide bonds, and disulfide bridges stabilize protein structures through strong covalent interactions. Non-covalent interactions like van der Waals forces, hydrogen bonds, electrostatic interactions, and hydrophobic effects also contribute to protein stability. These non-covalent interactions are weaker than covalent bonds but work together in large numbers to stabilize a protein's native conformation. Perturbations can disrupt this delicate balance of interactions and cause protein denaturation.
This document discusses various types of non-covalent interactions including van der Waals forces, hydrogen bonding, electrostatic interactions, and hydrophobic interactions. It provides details on the relative strengths of each interaction and their importance in maintaining the structure of biological molecules like proteins and nucleic acids. Specific examples highlighted include hydrogen bonding holding together the DNA double helix and hydrophobic interactions driving the association of nonpolar molecules in aqueous solutions.
The document discusses hydrophobic interactions and effects. It defines hydrophobicity as molecules that do not interact well with water, such as nonpolar substances. When these molecules are introduced into water, they aggregate together to minimize contact with water molecules. This occurs because breaking hydrogen bonds between water and the hydrophobic molecules is entropically unfavorable. The hydrophobic effect is driven by this entropy change and causes nonpolar substances to cluster together in aqueous solutions.
Secondary Structure Of Protein (Repeating structure of protein)Amrutha Hari
This document discusses the structure of proteins at various levels. It describes the primary, secondary, tertiary, and quaternary structures. The secondary structures discussed in detail include the alpha helix, beta pleated sheet, random coil, collagen helix, and beta turn. The alpha helix and beta pleated sheet are stabilized by hydrogen bonding between amino acids. The collagen helix structure provides strength and is the main component of connective tissues. Genetic disorders like Ehlers-Danlos syndrome and osteogenesis imperfecta result from defects in collagen structures. Ramachandran plots are used to visualize allowed backbone dihedral angles in protein structures.
The document summarizes the mechanisms of enzyme catalysis. It discusses how enzymes lower the activation energy of reactions by releasing binding energy when interacting with substrates. This allows enzymes to accelerate reactions by stabilizing transition states. There are three main types of catalytic mechanisms: acid-base catalysis, covalent catalysis, and metal ion catalysis. Acid-base catalysis involves proton transfers. Covalent catalysis forms temporary covalent bonds between enzymes and substrates. Metal ion catalysis uses metal ions like iron and copper to orient and stabilize reactive molecules in enzyme active sites.
A membrane protein is a protein molecule that is attached to, or associated with the membrane of a cell or an organelle.
More than half of all proteins interact with membranes.
I have tried to make a precise presentation on protein transport, targeting and sorting into organelle's other than nucleus. Hope this might help you. Comments are welcome.
WEAK INTERACTIONS IN AQUEOUS SYSTEMS AND FITNESS OF THE AQUEOUS ENVIRONMENT F...anjusha suki
Weak interactions like hydrogen bonding and van der Waals forces play an important role in maintaining the structures of biological molecules like proteins and DNA. These interactions are weak individually but add up to provide strong conformations. The more complementary the interacting structures, the better they fit together and the more stable the resulting structure. Hydrogen bonding specifically helps dissolve many compounds in water and is important for life's aqueous environment.
Abzymes, also known as catalytic antibodies, are monoclonal antibodies that exhibit enzymatic activity. They are able to bind to transition states of enzyme-catalyzed reactions with high specificity and affinity, stabilizing the transition state and increasing reaction rates. Abzymes can be artificially produced by immunizing animals with transition state analogs of reactions. They have potential applications in drug development, cancer treatment, and developing therapies for viral infections like HIV. Researchers have engineered an abzyme that can degrade an essential region of the HIV envelope protein, rendering the virus unable to infect cells.
1. Non-covalent interactions like electrostatic interactions, hydrogen bonds, van der Waals forces, and hydrophobic interactions play important roles in stabilizing macromolecular structures like proteins.
2. These interactions are weak but numerous, allowing for spontaneous assembly of larger structures. They also allow conformational changes important for biochemical functions while maintaining overall structure.
3. Electrostatic interactions depend on distance between charges and the dielectric constant of the medium, with an optimal distance of around 2.8 Angstroms. Hydrogen bonds are weaker than covalent bonds but important in structures. Van der Waals forces and hydrophobic interactions also contribute to stability.
Oligonucleotide synthesis - Problems and Challengesajithnandanam
The oligonucleotides are synthesized on solid supports from the 3’-end and the first monomer at this end is normally attached to a CPG(Controlled Pore Glass) or Polystyrene (PS).
The document discusses the Hill equation, which was formulated by Archibald Hill in 1910 to describe the sigmoidal oxygen binding curve of hemoglobin. The Hill equation can be used to describe the fraction of a macromolecule saturated by a ligand as a function of the ligand's concentration. It is useful for determining the degree of cooperativity between ligand binding sites. A Hill coefficient of n > 1 indicates positively cooperative binding, n < 1 indicates negatively cooperative binding, and n = 1 indicates noncooperative binding.
Folding depends upon sequence of Amino Acids not the Composition. Folding starts with the secondary structure and ends at quaternary structure.
Denaturation occur at secondary, tertiary & quaternary level but not at primary level.
The document discusses protein-protein interactions (PPIs) and methods used to study them. It defines PPIs as physical contacts between two or more proteins through biochemical or electrostatic forces. It describes different types of PPIs including homo-oligomers, hetero-oligomers, covalent and non-covalent interactions. Common methods to study PPIs are also summarized, such as yeast two-hybrid systems, co-immunoprecipitation, and protein interaction databases. The applications and importance of PPI research are mentioned including roles in various cellular processes and diseases.
The document discusses the structure and polymorphism of DNA. It describes how DNA is composed of two polynucleotide chains that form a double helix structure. The chains are held together by bonds between complementary nucleotide base pairs of adenine-thymine and guanine-cytosine. DNA can take on different helical structures, including A-DNA, B-DNA, and Z-DNA forms. A-DNA is a right-handed helix found in dehydrated DNA. B-DNA is the most common right-handed form with a 10.5 base pair turn. Z-DNA is a left-handed helix favored by alternating purine-pyrimidine sequences.
Enzymes use several catalytic mechanisms to lower the free energy of transition states and greatly increase reaction rates, including acid-base catalysis, covalent catalysis, metal ion catalysis, and bringing substrates into close proximity and proper orientation. Acid-base catalysis involves proton transfer from catalytic amino acid side chains. Covalent catalysis transiently forms covalent bonds between enzyme and substrate. Metal ion catalysis uses transition metals to orient substrates, mediate redox reactions, or stabilize charges. Proximity and orientation align substrates for reaction, while catalysis by approximation brings two substrates together for reaction.
Enzyme kinetics is the study of enzyme-catalyzed reaction rates. The Michaelis-Menten equation relates reaction velocity to substrate concentration and kinetic parameters. It describes the hyperbolic relationship between velocity and substrate concentration. The equation can be linearized into the Lineweaver-Burk plot for easier analysis. Enzyme inhibition studies help understand reaction mechanisms and are important for drug development, as most drugs function by inhibiting specific enzymes.
The following slides contains a brief comparison of the different forms of the DNA. It includes A-DNA, B-DNA , and Z-DNA.
It also briefs about the conditions that would favor the transition from one form to the another
This is based on protein-ligand interaction physical method, which gives us knowledge about how our body protein interacts with other molecule and protein function.
COVALENT MODIFICATION AND ZYMOGEN ACTIVATIONMariya Raju
1) Covalent modifications, both reversible and irreversible, play important roles in regulating enzyme function. Reversible modifications like phosphorylation fine-tune enzyme activity, while irreversible proteolysis activates zymogens into active enzymes.
2) Digestive enzymes like trypsinogen are synthesized as inactive zymogens to avoid unwanted catalysis, then activated through limited and specific proteolysis. This proteolysis removes inhibitory peptide sequences and allows catalytic activity.
3) Activation of zymogens through proteolytic cascades amplifies hormonal signals, allowing a small stimulus to elicit a large response. This cascade activation greatly increases the potency and efficiency of regulation compared to direct hormone binding.
Protein-DNA interactions can be either specific or non-specific. Specific interactions involve transcription factors that regulate gene expression by binding to DNA motifs through domains like helix-loop-helix, leucine zipper, or zinc finger motifs. Non-specific interactions involve histones that help structure DNA into nucleosomes within chromatin and can be chemically modified through methylation, demethylation, acetylation, and phosphorylation.
This document discusses the limits on rotation in protein backbones and defines the psi (ψ) and phi (φ) angles. It introduces the Ramachandran plot, which maps allowed combinations of ψ and φ angles based on steric constraints. The plot reveals preferred regions that correspond to common secondary structures like alpha helices and beta sheets. Understanding the steric limits on individual amino acid residues provides insight into how proteins fold into their specific three-dimensional shapes.
Frederick Sanger developed two important methods for protein sequencing: 1) using fluorodinitrobenzene to determine the N-terminal amino acid, and 2) cleaving proteins into fragments and piecing their sequences together. The standard strategy involves separating chains, identifying terminal residues, cleaving the protein, sequencing fragments, and reconstructing the full sequence. The Edman degradation method allows sequential removal of residues from the N-terminus. Mass spectrometry techniques like peptide mass fingerprinting and tandem mass spectrometry now dominate protein sequencing.
This document discusses the various energy components that contribute to intermolecular non-covalent interactions. It describes the main energy components as: electrostatic energy, exchange repulsion energy, polarization energy, charge transfer energy, and dispersion attraction. Electrostatic energy is the longest-ranging and depends on molecular moments. Exchange repulsion prevents electron overlap between molecules. Polarization energy arises from charge redistribution when molecules interact. Charge transfer involves small amounts of electron transfer between interacting molecules. Dispersion attraction exists for all atom pairs and is the sole interaction for rare gases. The individual energies are weak but can add up significantly in molecular environments like binding interactions.
Proteins are composed of amino acids and play many essential roles in the body. They have four levels of structure: primary, secondary, tertiary, and quaternary. The primary structure is the amino acid sequence, secondary involves hydrogen bonding into shapes like alpha helices and beta sheets, tertiary is the 3D folding of these structures, and quaternary involves the assembly of multiple protein subunits. Proteins serve as enzymes, hormones, antibodies, and structures. They undergo synthesis from amino acids and breakdown through catabolism. Disorders can occur if amino acid metabolism is disrupted.
WEAK INTERACTIONS IN AQUEOUS SYSTEMS AND FITNESS OF THE AQUEOUS ENVIRONMENT F...anjusha suki
Weak interactions like hydrogen bonding and van der Waals forces play an important role in maintaining the structures of biological molecules like proteins and DNA. These interactions are weak individually but add up to provide strong conformations. The more complementary the interacting structures, the better they fit together and the more stable the resulting structure. Hydrogen bonding specifically helps dissolve many compounds in water and is important for life's aqueous environment.
Abzymes, also known as catalytic antibodies, are monoclonal antibodies that exhibit enzymatic activity. They are able to bind to transition states of enzyme-catalyzed reactions with high specificity and affinity, stabilizing the transition state and increasing reaction rates. Abzymes can be artificially produced by immunizing animals with transition state analogs of reactions. They have potential applications in drug development, cancer treatment, and developing therapies for viral infections like HIV. Researchers have engineered an abzyme that can degrade an essential region of the HIV envelope protein, rendering the virus unable to infect cells.
1. Non-covalent interactions like electrostatic interactions, hydrogen bonds, van der Waals forces, and hydrophobic interactions play important roles in stabilizing macromolecular structures like proteins.
2. These interactions are weak but numerous, allowing for spontaneous assembly of larger structures. They also allow conformational changes important for biochemical functions while maintaining overall structure.
3. Electrostatic interactions depend on distance between charges and the dielectric constant of the medium, with an optimal distance of around 2.8 Angstroms. Hydrogen bonds are weaker than covalent bonds but important in structures. Van der Waals forces and hydrophobic interactions also contribute to stability.
Oligonucleotide synthesis - Problems and Challengesajithnandanam
The oligonucleotides are synthesized on solid supports from the 3’-end and the first monomer at this end is normally attached to a CPG(Controlled Pore Glass) or Polystyrene (PS).
The document discusses the Hill equation, which was formulated by Archibald Hill in 1910 to describe the sigmoidal oxygen binding curve of hemoglobin. The Hill equation can be used to describe the fraction of a macromolecule saturated by a ligand as a function of the ligand's concentration. It is useful for determining the degree of cooperativity between ligand binding sites. A Hill coefficient of n > 1 indicates positively cooperative binding, n < 1 indicates negatively cooperative binding, and n = 1 indicates noncooperative binding.
Folding depends upon sequence of Amino Acids not the Composition. Folding starts with the secondary structure and ends at quaternary structure.
Denaturation occur at secondary, tertiary & quaternary level but not at primary level.
The document discusses protein-protein interactions (PPIs) and methods used to study them. It defines PPIs as physical contacts between two or more proteins through biochemical or electrostatic forces. It describes different types of PPIs including homo-oligomers, hetero-oligomers, covalent and non-covalent interactions. Common methods to study PPIs are also summarized, such as yeast two-hybrid systems, co-immunoprecipitation, and protein interaction databases. The applications and importance of PPI research are mentioned including roles in various cellular processes and diseases.
The document discusses the structure and polymorphism of DNA. It describes how DNA is composed of two polynucleotide chains that form a double helix structure. The chains are held together by bonds between complementary nucleotide base pairs of adenine-thymine and guanine-cytosine. DNA can take on different helical structures, including A-DNA, B-DNA, and Z-DNA forms. A-DNA is a right-handed helix found in dehydrated DNA. B-DNA is the most common right-handed form with a 10.5 base pair turn. Z-DNA is a left-handed helix favored by alternating purine-pyrimidine sequences.
Enzymes use several catalytic mechanisms to lower the free energy of transition states and greatly increase reaction rates, including acid-base catalysis, covalent catalysis, metal ion catalysis, and bringing substrates into close proximity and proper orientation. Acid-base catalysis involves proton transfer from catalytic amino acid side chains. Covalent catalysis transiently forms covalent bonds between enzyme and substrate. Metal ion catalysis uses transition metals to orient substrates, mediate redox reactions, or stabilize charges. Proximity and orientation align substrates for reaction, while catalysis by approximation brings two substrates together for reaction.
Enzyme kinetics is the study of enzyme-catalyzed reaction rates. The Michaelis-Menten equation relates reaction velocity to substrate concentration and kinetic parameters. It describes the hyperbolic relationship between velocity and substrate concentration. The equation can be linearized into the Lineweaver-Burk plot for easier analysis. Enzyme inhibition studies help understand reaction mechanisms and are important for drug development, as most drugs function by inhibiting specific enzymes.
The following slides contains a brief comparison of the different forms of the DNA. It includes A-DNA, B-DNA , and Z-DNA.
It also briefs about the conditions that would favor the transition from one form to the another
This is based on protein-ligand interaction physical method, which gives us knowledge about how our body protein interacts with other molecule and protein function.
COVALENT MODIFICATION AND ZYMOGEN ACTIVATIONMariya Raju
1) Covalent modifications, both reversible and irreversible, play important roles in regulating enzyme function. Reversible modifications like phosphorylation fine-tune enzyme activity, while irreversible proteolysis activates zymogens into active enzymes.
2) Digestive enzymes like trypsinogen are synthesized as inactive zymogens to avoid unwanted catalysis, then activated through limited and specific proteolysis. This proteolysis removes inhibitory peptide sequences and allows catalytic activity.
3) Activation of zymogens through proteolytic cascades amplifies hormonal signals, allowing a small stimulus to elicit a large response. This cascade activation greatly increases the potency and efficiency of regulation compared to direct hormone binding.
Protein-DNA interactions can be either specific or non-specific. Specific interactions involve transcription factors that regulate gene expression by binding to DNA motifs through domains like helix-loop-helix, leucine zipper, or zinc finger motifs. Non-specific interactions involve histones that help structure DNA into nucleosomes within chromatin and can be chemically modified through methylation, demethylation, acetylation, and phosphorylation.
This document discusses the limits on rotation in protein backbones and defines the psi (ψ) and phi (φ) angles. It introduces the Ramachandran plot, which maps allowed combinations of ψ and φ angles based on steric constraints. The plot reveals preferred regions that correspond to common secondary structures like alpha helices and beta sheets. Understanding the steric limits on individual amino acid residues provides insight into how proteins fold into their specific three-dimensional shapes.
Frederick Sanger developed two important methods for protein sequencing: 1) using fluorodinitrobenzene to determine the N-terminal amino acid, and 2) cleaving proteins into fragments and piecing their sequences together. The standard strategy involves separating chains, identifying terminal residues, cleaving the protein, sequencing fragments, and reconstructing the full sequence. The Edman degradation method allows sequential removal of residues from the N-terminus. Mass spectrometry techniques like peptide mass fingerprinting and tandem mass spectrometry now dominate protein sequencing.
This document discusses the various energy components that contribute to intermolecular non-covalent interactions. It describes the main energy components as: electrostatic energy, exchange repulsion energy, polarization energy, charge transfer energy, and dispersion attraction. Electrostatic energy is the longest-ranging and depends on molecular moments. Exchange repulsion prevents electron overlap between molecules. Polarization energy arises from charge redistribution when molecules interact. Charge transfer involves small amounts of electron transfer between interacting molecules. Dispersion attraction exists for all atom pairs and is the sole interaction for rare gases. The individual energies are weak but can add up significantly in molecular environments like binding interactions.
Proteins are composed of amino acids and play many essential roles in the body. They have four levels of structure: primary, secondary, tertiary, and quaternary. The primary structure is the amino acid sequence, secondary involves hydrogen bonding into shapes like alpha helices and beta sheets, tertiary is the 3D folding of these structures, and quaternary involves the assembly of multiple protein subunits. Proteins serve as enzymes, hormones, antibodies, and structures. They undergo synthesis from amino acids and breakdown through catabolism. Disorders can occur if amino acid metabolism is disrupted.
The document discusses van der Waals forces, their characteristics, types (Keesom, Debye, London dispersion forces), and significance. Van der Waals forces are weak intermolecular forces between molecules caused by interactions between permanent or induced molecular dipoles. They are important in protein folding, graphite bonding, polymer formation, animal climbing/walking, and modern technologies that aim to mimic gecko adhesion.
Mass spectrometry is a technique that converts a sample to gas-phase ions which are then separated by mass and charge. It involves ionization of the sample using electron bombardment or other methods, mass analysis using magnetic or electric fields to separate ions, and detection of ion abundances. Mass spectrometry can be used to determine molecular masses and obtain structural information through fragmentation patterns.
The document summarizes the four laws of thermodynamics:
1) The first law states that energy cannot be created or destroyed, only changed in form.
2) The second law states that the entropy of an isolated system always increases.
3) The third law states that the entropy of a system approaches a minimum, zero, as the temperature approaches absolute zero.
4) There is no universally accepted fourth law, but some proposals include the Onsager reciprocal relations regarding heat and matter flow parameters.
Melchor J. presented a teaching demo on the first law and of physics. The first law of thermodynamics states that energy cannot be created or destroyed, only changed from one form to another, and the total amount of energy in a system remains constant. It also states that the change in a system's internal energy during a process depends only on the initial and final states, not the path between them.
The document defines research as a careful, systematic investigation to gain new knowledge. It discusses the objectives of research as exploratory, descriptive, diagnostic, and hypothesis testing. Motivations for research include career advancement, solving problems, intellectual challenge, and helping society. Research is characterized as careful, objective, and seeking to integrate facts. Unethical practices include deceiving subjects, lack of informed consent, and fabricating data. The significance of research is that it provides the basis for policies and solving problems while respecting ethics like informed consent and minimizing harm.
The document discusses the formation of covalent bonds between non-metallic elements using dot-and-cross diagrams. It explains that in covalent bonding, atoms share electron pairs rather than gaining or losing electrons in order to achieve a noble gas configuration. Chlorine atoms form a single covalent bond by each sharing one electron pair between them to fill their octets. Similarly, oxygen atoms form a double covalent bond by each sharing two electron pairs to fill their octets.
This document provides information about chemical bonding over 14 lectures. It discusses various theories of bonding including Kossel-Lewis concept, VSEPR theory, valence bond theory and molecular orbital theory. It describes different types of bonds such as ionic, covalent and dative bonds. It also discusses topics like bond polarity, dipole moment, Fajan's rule, VSEPR theory, bond properties and factors affecting stability of molecules.
This document discusses the structure of proteins at multiple levels:
1. It describes the primary structure of proteins as the unique sequence of amino acids determined by genes. The peptide bond links amino acids and is rigid and planar.
2. Secondary structures like alpha helices and beta sheets form due to hydrogen bonding between amino acids in close proximity in the sequence. Alpha helices are tightly coiled and stabilized by hydrogen bonds between amino and carbonyl groups.
3. Tertiary structure refers to the compact three-dimensional folding of the protein chain, bringing hydrophobic residues inwards and hydrophilic outwards. Disulfide bonds and other interactions contribute to tertiary structure.
4. Some proteins have quaternary structure
This document discusses protein structure and denaturation. It explains that protein structure is stabilized by covalent and non-covalent bonds. Denaturation is the loss of a protein's native structure, resulting in changes to its physical, chemical, and biological properties. Denaturation can be caused by physical agents like heat or chemicals agents like acids. Characteristics of denatured proteins include losing biological activity and becoming insoluble in their original solvent. Denaturation is usually irreversible but some proteins can renature by removing the denaturing agent.
B.sc(microbiology, biotechnology and biochemistry) ii inorganic chemistry uni...Rai University
1. Hydrogen bonding occurs when a hydrogen atom covalently bonded to an electronegative atom such as oxygen or fluorine forms an additional electrostatic bond with another electronegative atom.
2. Hydrogen bonding is important in biological molecules like proteins and nucleic acids and plays a role in life processes. It affects properties like boiling points and viscosity.
3. Ionic compounds are composed of positively and negatively charged ions held together by strong electrostatic attractions called lattice energy. They have high melting and boiling points and conduct electricity when molten or dissolved in water.
The document discusses the four levels of protein structure - primary, secondary, tertiary, and quaternary. It explains the significance of each level. The primary structure is the sequence of amino acids. The secondary structure involves hydrogen bonding that forms alpha helices and beta sheets. Tertiary structure describes the overall 3D shape formed by interactions between secondary structures. Quaternary structure refers to complexes of multiple polypeptide chains. The document also discusses membrane proteins and the roles of polar and non-polar amino acids in protein structure and function.
The document provides information on proteins, including:
- Proteins are the most abundant organic molecules and constitute about 50% of cellular dry weight. They perform structural and dynamic functions in the cell.
- Proteins are polymers of amino acids. There are 20 standard amino acids that make up proteins. Amino acids contain amino and carboxyl groups and have varying side chains that determine their properties.
- The primary structure of a protein is its unique sequence of amino acids as determined by genes. Higher levels of structure include secondary, tertiary and quaternary organization that influence a protein's shape and function.
This document discusses the classification of proteins in three ways: by function, chemical nature/solubility, and nutrition. Functionally, proteins are classified as structural, enzymatic, transport, hormonal, contractile, storage, genetic, defense, or receptor proteins. Chemically, proteins are simple/globular or fibrous based on shape/solubility, and can also be conjugated or derived. Nutritionally, proteins are complete, partially incomplete, or incomplete based on their essential amino acid content and ability to promote growth.
The document discusses various drug targets including cell membranes, carbohydrates, and proteins like receptors and enzymes. It describes the structure and function of receptors, how they receive chemical messengers and transmit signals into cells. It also covers different types of receptor-ligand interactions and how drugs can act as agonists or antagonists at receptor binding sites to modulate cellular responses.
This document discusses entropy and its relationship to the second law of thermodynamics. It defines entropy as a property that depends only on the end states of a reversible process between two states. The document proves that the entropy of a thermally isolated system never decreases, and instead either increases or remains constant, in accordance with the second law of thermodynamics. It also discusses how entropy is related to the disorder of a system on a microscopic scale, with irreversible processes increasing disorder and entropy.
This document discusses the synthesis of three classes of organic compounds: eicosanoids, glycerolipids, and isoprenoids. It mentions the enzymes cyclooxygenase and IPP isomerase which are involved in the synthesis pathways. The formation of isopentenyl pyrophosphate is also noted. Cholesterol synthesis from IPP is outlined, going through squalene monooxygenase, 2,3-oxidosqualene, lanosterol cyclase, and 20 steps to ultimately produce cholesterol.
Protein engineering involves modifying protein structures using recombinant DNA technology or chemical treatment to produce proteins with desirable functions for medicine, industry, and agriculture. Applications include improving existing proteins, creating novel proteins, and studying membrane receptor proteins targeted by pharmaceuticals. Biosensors detect substances using biological components like cells or enzymes linked to transducers. Nanobiotechnology combines nanotechnology with biology for applications such as disease diagnostics, drug delivery, and green chemistry. Microarrays allow analyzing thousands of samples simultaneously through DNA, protein, tissue, whole-cell, and small-molecular arrays. Biotechnology produces diagnostics and therapeutics for many diseases using natural products, biopolymers, recombinant proteins, gene therapy, cell transplants, and stimulating
The document discusses different types of chemical bonds including polar and nonpolar bonds. It explains that polarity refers to differences in electronegativity between atoms in a bond. Polar bonds form when electrons are shared unequally, resulting in partial positive and negative charges on different parts of the molecule. Nonpolar bonds share electrons equally. The document also describes properties influenced by bond polarity like boiling point and solubility. It discusses hydrogen bonding, ionic bonding, and van der Waals forces as types of intermolecular forces.
The document discusses different types of intramolecular and intermolecular forces. It describes ionic bonds as the strong electrostatic attraction between oppositely charged ions. Covalent bonds are described as the sharing of electron pairs between atoms. It also discusses hydrogen bonding, dipole-dipole interactions, and van der Waals forces as different types of intermolecular forces that are weaker than ionic or covalent bonds.
The document discusses kinetic molecular theory and intermolecular forces. It defines the kinetic molecular theory and describes the arrangement, kinetic energy, and motion of particles in solids, liquids, and gases. It then discusses the four main types of intermolecular forces: ion-dipole forces, dipole-dipole forces, London dispersion forces, and hydrogen bonding. Ion-dipole forces result from the attraction between ions and polar molecules. Dipole-dipole forces exist between polar molecules due to partial charges. London dispersion forces are induced dipole forces between all molecules. Hydrogen bonding is a strong dipole-dipole force between a hydrogen and electronegative atom. The document provides examples
Intermolecular forces are weak attractive forces between neighboring molecules that include ion-dipole forces, dipole-dipole forces, London dispersion forces, and hydrogen bonding. Ion-dipole forces result from the attraction between ions and polar molecules. Dipole-dipole forces exist between polar molecules. London dispersion forces are induced dipole interactions between all molecules. Hydrogen bonding is a special type of dipole-dipole force between a hydrogen atom bonded to an electronegative atom and another electronegative atom. These intermolecular forces help explain differences in boiling points, melting points, and densities of substances.
1. Organic reaction mechanisms involve the reaction of a substrate with a reagent, forming intermediates and ultimately products.
2. Bond cleavage can occur through either a heterolytic or homolytic process. Heterolytic cleavage leads to the formation of ions while homolytic cleavage leads to free radicals.
3. Electrophiles are electron seeking species that attack nucleophilic centers, while nucleophiles are electron pairing species that attack electrophilic centers. Common electrophiles include carbocations and carbonyl groups, while common nucleophiles include carbanions.
This document defines and differentiates the main types of intermolecular forces: dipole-dipole forces, London dispersion forces, ion-dipole forces, and hydrogen bonding. It provides examples of polar and nonpolar molecules, and describes the characteristics of each type of intermolecular force, including their relative strengths and the molecules between which they typically occur.
The document discusses different types of intermolecular forces including London dispersion forces, dipole-dipole interactions, and hydrogen bonding. It explains that these intermolecular forces determine properties of liquids and solids, such as melting and boiling points, as they must be overcome for phase changes to occur. The forces arise from electrostatic interactions between charged regions in molecules. Hydrogen bonding is a particularly strong form of dipole-dipole interaction.
The document discusses the three main types of intermolecular forces: dipole-dipole forces, London dispersion forces, and hydrogen bonding. It describes each type of force, including that dipole-dipole forces exist between polar molecules, London dispersion forces exist between all molecules, and hydrogen bonding specifically refers to the attraction between hydrogen atoms bonded to electronegative atoms like N, O, or F. The document also discusses how these intermolecular forces can explain the physical properties of liquids and some solids.
This document provides an overview of supramolecular chemistry. It begins with a brief history and definitions of key terms like supramolecular chemistry and self-assembly. It then describes various types of non-covalent interactions that hold supramolecular structures together, such as hydrogen bonding, metal-ligand interactions, π-π stacking, and hydrophobic effects. Examples are given of self-assembled structures like grids, helicates, and polyhedral cages. The document concludes by noting the increasing sophistication of supramolecular systems incorporating components like fullerenes and nanoparticles for applications in nanotechnology.
This document discusses secondary bonding, which includes several types of weak physical bonds between molecules:
- Permanent dipoles can form dipole-dipole bonds through interactions between asymmetric charges on different molecules. These bonds are directional and weaker than chemical bonds.
- Van der Waals bonding is the weakest type of secondary bonding and arises from induced dipole interactions between molecules caused by fluctuations in electron density.
- Hydrogen bonding is a type of dipole-dipole bonding that occurs between polar bonds containing hydrogen, such as between water molecules. It is stronger than van der Waals bonding.
- Secondary bonds influence many material properties, such as boiling points and mechanical strength of polymers and other materials.
Electro osmosis ,colligative propertries of colloids ,electrokinetic properti...Anand P P
electro osmosis.that topics deals with colloids and their one of the colligative properties that is electro kinetic property.under the electrokinetic colligative property of colloids consist 2 properties mainly electrophoresis and elecoosmosis.the electro osmosis have several application properties.the electroosmosis is mainly deals with the charge of colloidal system and their movements opposite charges.electrical double layer theory.
Chem 2 - Intermolecular Forces & Phases of Matter II Lumen Learning
1) There are several types of intermolecular forces ranging from strongest to weakest - hydrogen bonding, dipole-dipole interactions, dipole-induced dipole interactions, and dispersion forces.
2) Hydrogen bonding is the strongest and involves the electrostatic attraction between a hydrogen atom covalently bonded to a highly electronegative atom like N, O, or F, and another electronegative atom's lone pair of electrons.
3) Dipole-dipole interactions occur between polar molecules that have partially positive and negative ends that electrostatically attract each other, while dipole-induced dipole interactions involve a polar molecule inducing a dipole in a neighboring nonpolar molecule.
electronegativity in molecules covalent bondingAmelHanafi3
The document discusses electronegativity and how it relates to bond polarity. Electronegativity is a measure of an atom's attraction for electrons, and differences in electronegativity between atoms determine if a bond is polar or nonpolar. Polar covalent bonds form when atoms pull electrons unequally, resulting in partial charges. Whether a molecule is polar depends on both bond polarity and molecular symmetry. The properties of covalent compounds, such as their relatively low melting/boiling points, result from weak intermolecular forces like van der Waals forces, dipole-dipole interactions, and hydrogen bonding.
This document discusses intramolecular and intermolecular bonding. It begins by outlining the learning objectives which are to describe trends in the periodic table, understand ionic and covalent bonds, electronegativity, and molecular shape. It then asks why water is important to life and why salts are essential to our bodies. It discusses the periodic table, bonding types including covalent, polar covalent, and ionic. It explains electronegativity and its role in determining bond polarity. It discusses how salt dissolves in water due to water's polar nature and ability to form hydrogen bonds. It explains that hydrogen bonding between water molecules is responsible for water's high boiling point and the fact that ice floats in liquid water
This document discusses intermolecular forces and the properties they impart to liquids and solids. It describes three main types of intermolecular forces: dipole-dipole forces between polar molecules, London dispersion forces present in all molecules, and strong hydrogen bonding between a hydrogen atom and electronegative atoms like N, O, F. Hydrogen bonding gives ice its unusual properties and is important in biological molecules like DNA. The strengths of these different intermolecular forces influence physical properties of substances like melting and boiling points. Liquids exhibit surface tension, capillary action, and viscosity due to the attractive intermolecular forces between their molecules.
Okay, let's break this down step-by-step:
* We are given: 1 mole of ice at -25°C
* Heat of fusion of ice = 6.01 kJ/mol
* Heat of vaporization of water = 40.7 kJ/mol
* Specific heat of ice = 2.09 J/g°C
* Specific heat of water = 4.18 J/g°C
1) Heat ice from -25°C to 0°C:
Q = m * c * ΔT
Q = (18 g) * (2.09 J/g°C) * (25°C) = 903 J
2) Heat
Marker assisted selection of male sterility in rice --vipin Vipin Kannan
This document provides information on various methods of inducing male sterility in plants, especially rice, for the purpose of hybrid seed production. It discusses chemical, genetic, and transgenic approaches. Specifically, it describes cytoplasmic male sterility (CMS), nuclear male sterility (NMS), and cytoplasmic-genetic male sterility (CGMS). It also discusses the use of marker-assisted selection (MAS) to more efficiently select for male sterility genes and introgress them into adapted varieties through techniques like marker-assisted backcrossing (MAB). Overall, the document outlines methods for inducing and tracking male sterility that can facilitate efficient hybrid rice breeding programs.
Disease related to aminoacid metabolosmVipin Kannan
This document discusses diseases related to amino acid metabolism, including alkaptonuria, phenylketonuria, and homocystinuria. It provides an overview of amino acid catabolism and degradation pathways. Specific genetic defects that cause these diseases are described, including symptoms and diagnostic criteria. Treatment options are mentioned for managing associated health issues.
Stem-cell based gene therapy aims to genetically modify cells to resist HIV infection through three main strategies: 1) targeting cellular genes essential for viral replication like CCR5, 2) directly targeting HIV gene expression, and 3) introducing genes that interfere with HIV replication. Combination therapy employing multiple genetic modifications may help prevent viral escape. Engineering immunity against HIV through therapeutic vaccines or modified T-cells and stem cells shows promise in controlling infection.
Interleukins are a group of cytokines that were first seen to be expressed by white blood cells and act as signaling molecules between immune cells. They promote the development and differentiation of T and B lymphocytes. The majority of interleukins are synthesized by helper T cells, monocytes, macrophages, and endothelial cells. There are several common families of interleukins that play various roles, such as interleukin 1 which participates in immune responses and inflammation, interleukin 2 which induces T cell proliferation, and interleukin 6 which stimulates antibody production.
This document discusses global warming and the greenhouse effect. It explains that human activity is increasing greenhouse gases which thickens the layer trapping heat in the atmosphere and gradually increases earth's temperature. The greenhouse effect was discovered in 1824 and the main greenhouse gases are carbon dioxide, methane, CFCs and nitrous oxide. These gases are essential for maintaining a habitable temperature on Earth but human activities like burning fossil fuels have increased their levels since the pre-industrial era. This warming effects ecosystems and humans in various ways like rising sea levels and more extreme weather. Solutions proposed to reduce global warming include using renewable energy, afforestation, energy efficiency and international agreements like the Kyoto Protocol.
This document discusses the biodegradation of starch by microorganisms. It begins by defining biodegradation and starch. Starch is made of amylose and amylopectin and can be degraded aerobically or anaerobically. Many bacteria and fungi produce amylase enzymes that break down starch into simpler sugars like maltose and glucose. The document then covers the industrial applications of starch degradation in food processing, brewing, textiles, fuel production, detergents, and more. Key microbes used include Bacillus species, Aspergillus, and Saccharomyces.
Ribozymes are RNA molecules that possess catalytic activity. The first ribozymes were discovered in the 1980s by Thomas R. Cech and Sidney Altman. There are several naturally occurring ribozymes including ribosomes, RNase P, group I and group II introns, hairpin ribozymes, hammerhead ribozymes, and more. Ribozymes can be classified as either small or large based on size. They require metal ions like Mg2+ and Mn2+ for catalytic activity. Both natural and artificial ribozymes have potential applications in research, gene therapy, and as therapeutic agents.
The document discusses the Polymerase Chain Reaction (PCR) technique. It begins by explaining that PCR amplifies DNA fragments rapidly outside of a cell. It then notes that PCR was invented in 1984 as a way to make numerous copies of DNA fragments in the laboratory. The document proceeds to describe the components needed for PCR, including DNA, primers, nucleotides, DNA polymerase, and thermal cyclers. It explains the three step PCR process of denaturation, annealing of primers, and extension of DNA. Finally, it outlines several applications and variants of the PCR technique.
This document discusses biofortification of rice through conventional breeding and genetic engineering techniques. It provides a brief history of rice hybridization research and development. It then discusses various methods used to biofortify rice with micronutrients like vitamin A, folate, iron, zinc, and lysine. Case studies on developing golden rice enriched with beta-carotene and rice enriched with soy glycinin protein are described. Advantages of biofortified rice in reducing micronutrient deficiencies and disadvantages related to costs and access are noted.
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptxMAGOTI ERNEST
Although Artemia has been known to man for centuries, its use as a food for the culture of larval organisms apparently began only in the 1930s, when several investigators found that it made an excellent food for newly hatched fish larvae (Litvinenko et al., 2023). As aquaculture developed in the 1960s and ‘70s, the use of Artemia also became more widespread, due both to its convenience and to its nutritional value for larval organisms (Arenas-Pardo et al., 2024). The fact that Artemia dormant cysts can be stored for long periods in cans, and then used as an off-the-shelf food requiring only 24 h of incubation makes them the most convenient, least labor-intensive, live food available for aquaculture (Sorgeloos & Roubach, 2021). The nutritional value of Artemia, especially for marine organisms, is not constant, but varies both geographically and temporally. During the last decade, however, both the causes of Artemia nutritional variability and methods to improve poorquality Artemia have been identified (Loufi et al., 2024).
Brine shrimp (Artemia spp.) are used in marine aquaculture worldwide. Annually, more than 2,000 metric tons of dry cysts are used for cultivation of fish, crustacean, and shellfish larva. Brine shrimp are important to aquaculture because newly hatched brine shrimp nauplii (larvae) provide a food source for many fish fry (Mozanzadeh et al., 2021). Culture and harvesting of brine shrimp eggs represents another aspect of the aquaculture industry. Nauplii and metanauplii of Artemia, commonly known as brine shrimp, play a crucial role in aquaculture due to their nutritional value and suitability as live feed for many aquatic species, particularly in larval stages (Sorgeloos & Roubach, 2021).
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
Travis Hills' Endeavors in Minnesota: Fostering Environmental and Economic Pr...Travis Hills MN
Travis Hills of Minnesota developed a method to convert waste into high-value dry fertilizer, significantly enriching soil quality. By providing farmers with a valuable resource derived from waste, Travis Hills helps enhance farm profitability while promoting environmental stewardship. Travis Hills' sustainable practices lead to cost savings and increased revenue for farmers by improving resource efficiency and reducing waste.
The ability to recreate computational results with minimal effort and actionable metrics provides a solid foundation for scientific research and software development. When people can replicate an analysis at the touch of a button using open-source software, open data, and methods to assess and compare proposals, it significantly eases verification of results, engagement with a diverse range of contributors, and progress. However, we have yet to fully achieve this; there are still many sociotechnical frictions.
Inspired by David Donoho's vision, this talk aims to revisit the three crucial pillars of frictionless reproducibility (data sharing, code sharing, and competitive challenges) with the perspective of deep software variability.
Our observation is that multiple layers — hardware, operating systems, third-party libraries, software versions, input data, compile-time options, and parameters — are subject to variability that exacerbates frictions but is also essential for achieving robust, generalizable results and fostering innovation. I will first review the literature, providing evidence of how the complex variability interactions across these layers affect qualitative and quantitative software properties, thereby complicating the reproduction and replication of scientific studies in various fields.
I will then present some software engineering and AI techniques that can support the strategic exploration of variability spaces. These include the use of abstractions and models (e.g., feature models), sampling strategies (e.g., uniform, random), cost-effective measurements (e.g., incremental build of software configurations), and dimensionality reduction methods (e.g., transfer learning, feature selection, software debloating).
I will finally argue that deep variability is both the problem and solution of frictionless reproducibility, calling the software science community to develop new methods and tools to manage variability and foster reproducibility in software systems.
Exposé invité Journées Nationales du GDR GPL 2024
hematic appreciation test is a psychological assessment tool used to measure an individual's appreciation and understanding of specific themes or topics. This test helps to evaluate an individual's ability to connect different ideas and concepts within a given theme, as well as their overall comprehension and interpretation skills. The results of the test can provide valuable insights into an individual's cognitive abilities, creativity, and critical thinking skills
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
Phenomics assisted breeding in crop improvementIshaGoswami9
As the population is increasing and will reach about 9 billion upto 2050. Also due to climate change, it is difficult to meet the food requirement of such a large population. Facing the challenges presented by resource shortages, climate
change, and increasing global population, crop yield and quality need to be improved in a sustainable way over the coming decades. Genetic improvement by breeding is the best way to increase crop productivity. With the rapid progression of functional
genomics, an increasing number of crop genomes have been sequenced and dozens of genes influencing key agronomic traits have been identified. However, current genome sequence information has not been adequately exploited for understanding
the complex characteristics of multiple gene, owing to a lack of crop phenotypic data. Efficient, automatic, and accurate technologies and platforms that can capture phenotypic data that can
be linked to genomics information for crop improvement at all growth stages have become as important as genotyping. Thus,
high-throughput phenotyping has become the major bottleneck restricting crop breeding. Plant phenomics has been defined as the high-throughput, accurate acquisition and analysis of multi-dimensional phenotypes
during crop growing stages at the organism level, including the cell, tissue, organ, individual plant, plot, and field levels. With the rapid development of novel sensors, imaging technology,
and analysis methods, numerous infrastructure platforms have been developed for phenotyping.
ESR spectroscopy in liquid food and beverages.pptxPRIYANKA PATEL
With increasing population, people need to rely on packaged food stuffs. Packaging of food materials requires the preservation of food. There are various methods for the treatment of food to preserve them and irradiation treatment of food is one of them. It is the most common and the most harmless method for the food preservation as it does not alter the necessary micronutrients of food materials. Although irradiated food doesn’t cause any harm to the human health but still the quality assessment of food is required to provide consumers with necessary information about the food. ESR spectroscopy is the most sophisticated way to investigate the quality of the food and the free radicals induced during the processing of the food. ESR spin trapping technique is useful for the detection of highly unstable radicals in the food. The antioxidant capability of liquid food and beverages in mainly performed by spin trapping technique.
BREEDING METHODS FOR DISEASE RESISTANCE.pptxRASHMI M G
Plant breeding for disease resistance is a strategy to reduce crop losses caused by disease. Plants have an innate immune system that allows them to recognize pathogens and provide resistance. However, breeding for long-lasting resistance often involves combining multiple resistance genes
Current Ms word generated power point presentation covers major details about the micronuclei test. It's significance and assays to conduct it. It is used to detect the micronuclei formation inside the cells of nearly every multicellular organism. It's formation takes place during chromosomal sepration at metaphase.
Nucleophilic Addition of carbonyl compounds.pptxSSR02
Nucleophilic addition is the most important reaction of carbonyls. Not just aldehydes and ketones, but also carboxylic acid derivatives in general.
Carbonyls undergo addition reactions with a large range of nucleophiles.
Comparing the relative basicity of the nucleophile and the product is extremely helpful in determining how reversible the addition reaction is. Reactions with Grignards and hydrides are irreversible. Reactions with weak bases like halides and carboxylates generally don’t happen.
Electronic effects (inductive effects, electron donation) have a large impact on reactivity.
Large groups adjacent to the carbonyl will slow the rate of reaction.
Neutral nucleophiles can also add to carbonyls, although their additions are generally slower and more reversible. Acid catalysis is sometimes employed to increase the rate of addition.
2. COVALENT INTERACTIONS
• Covalent interactions (bonds) provide the glue that holds biopolymers together. Covalent
bond energies are on the order of 100 kcal/mole.
3. NON COVALENT INTERACTIONS
• A non-covalent interaction differs from a covalent bond in that it does not involve
the sharing of electrons, but rather involves more dispersed variations
of electromagnetic interactions between molecules or within a molecule.
• The energy released in the formation of non-covalent interactions is typically on the
order of 1-5 kcal/mol .
• Non-covalent interactions can be generally classified into 4
categories: electrostatic, π-effects, van der Waals forces, and hydrophobic effects.
• In fact, van der Waals forces are responsible for why geckos can walk up and down
walls!
4. • Non-covalent forces drive spontaneous folding of proteins and nucleic acids
and mediate recognition of complementary molecular surfaces.
• Noncovalent forces dictate conformation and interaction in biological
systems.
• Non-covalent interactions are the dominant type of interaction
between supermolecules in supermolecular chemistry.
6. IONIC
• It involve the attraction of ions or molecules with full permanent charges of
opposite signs.
• Ionic interactions occur between cations and anions.
• These bonds are non-directional, and strength depends on the distance of
separation (r) according to 1/r2. Strength also depends on the medium
(dielectric constant), and is less in polar than nonpolar solvents.
7. H-BONDING
• A hydrogen bond (H-bond), is a specific type of dipole-dipole interaction that
involves the interaction between a partially-positive hydrogen atom and a highly
electronegative atom .
• It is technically not a covalent bond, but instead electronegative, partially-negative
oxygen, nitrogen, sulfur, or fluorine is classified as a very strong dipole-dipole (non-
covalent) interaction.
• Most commonly, the strength of hydrogen bonds lies between 0 - 4 kcal/mol, but
can sometimes be as strong as 40 kcal/mol
8.
9. HALOGEN BONDING
• Halogen bonding is a type of non-covalent interaction which does not
involve the formation nor breaking of actual bonds, but rather is similar to
the dipole-dipole interaction known as hydrogen bonding.
• In halogen bonding, a halogen atom acts as an electrophile, or electron-
seeking species, and forms a weak electrostatic interaction with
a nucleophile, or electron-rich species.
• The nucleophilic agent in these interactions tends to be
highlyelectronegative (such as oxygen, nitrogen, or sulfur), or may
be anionic, bearing a negative formal charge.
• As compared to hydrogen bonding, the halogen atom takes the place of the
partially-positively charged hydrogen as the electrophile.
10. VAN DER WAALS FORCES
• Van der Waals Forces are a subset of electrostatic interactions involving permanent
or induced dipoles (or multipoles). These include the following:
• permanent dipole-dipole interactions, alternatively called the Keesom force
• dipole-induced dipole interactions, or the Debye force
• induced dipole-induced dipole interactions, commonly referred to as London
dispersion forces
• Note: Although hydrogen bonding and halogen bonding are both forms of dipole-
dipole interactions, these are typically not classified as Van der Waals Forces by
convention.
11. Dipole-Dipole
Dipole-dipole interactions are electrostatic interactions between
permanent dipoles in molecules. These interactions tend to align
the molecules to increase attraction (reducing potential energy).
Normally, dipoles are associated with electronegative atoms,
including (but not limited to) oxygen, nitrogen, sulfur, and fluorine.
12.
13. DIPOLE-INDUCED DIPOLE
• A dipole-induced dipole interaction (Debye force) is due to the approach of a
molecule with a permanent dipole to another non-polar molecule with no
permanent dipole.
• This approach causes the electrons of the non-polar molecule to
be polarized toward or away from the dipole (or "induce" a dipole) of the
approaching molecule.
•
14. LONDON DISPERSION FORCES
• London dispersion forces are the weakest type of non-covalent interaction.
• They are also known as "induced dipole-induced dipole interactions", and
form from molecules that inherently do not have permanent dipoles.
• They are caused by the temporary repulsion of electrons away from the
electrons of a neighboring molecule, leading to a partially-positive dipole on
one molecule and a partially-negative dipole on another molecule.
• Hexane is a good example of a molecule with no polarity or highly
electronegative atoms.
15.
16. π-EFFECTS
• π-effects can be broken down into numerous categories, including ,
π-π interactions, cation-π & anion-π interactions, and polar-π interactions.
• In general, π-effects are associated with the interactions of molecules with the π-
systems of conjugated molecules such as benzene.
17. π-π INTERACTION
• π-π interactions are associated with the interaction between the π-orbitals of a
molecular system.
• For a simple example, a benzene ring, with its fully conjugated π cloud, will interact
in two major ways and one minor way’ with a neighboring benzene ring through a
π-π interaction.
• The two major ways that benzene stacks are edge-to-face, with an enthalpy of ~2
kcal/mol, and displaced (or slip stacked), with an enthalpy of ~2.3 kcal/mol.
Interestingly, the sandwich configuration is not nearly as stable of an interaction as
the previously two mentioned due to high electrostatic repulsion of the electrons in
the π orbitals.
18. CATION π&ANION π
• Cation-π interactions involve the positive charge of
a cation interacting with the electrons in a π-system of a
molecule.
• This interaction is surprisingly strong (as strong or stronger
than H-bonding in some contexts), and has many potential
applications in chemical sensors.
• For example, the sodium ion can easily sit atop the π cloud of a
benzene molecule, with C6 symmetry (for more on point groups
and molecular symmetry.
19. • Anion-π interactions are very similar to cation-π interactions,
but reversed.
• In this case, an anion sits atop an electron-poor π-system,
usually established by the placement of electron-withdrawing
substituents on the conjugated molecule.
20. POLAR-π
• Polar-π interactions involve molecules with permanent dipoles (such as water)
interacting with the quadrupole moment of a π-system (such as that in benzene .
• While not as strong as a cation-π interaction, these interactions can be quite
strong (~1-2 kcal/mol), and are commonly involved in protein folding and
crystallinity of solids containing both hydrogen bonding and π-systems.
• In fact, any molecule with a hydrogen bond donor (hydrogen bound to a highly
electronegative atom) will have favorable electrostatic interactions with the
electron-rich π-system of a conjugated molecule.
21. HYDROPHOBIC EFFECT
• The hydrophobic effect is the desire for non-polar molecules to
aggregate in aqueous solutions in order to separate from water.
• This phenomenon leads to minimum exposed surface area of
non-polar molecules to the polar water molecules (typically
spherical droplets), and is commonly used in biochemistry to
study protein folding and other various biological phenomenon.
• olive oil in water