This PPT is about the solvent system definition of acids and bases in inorganic chemistry . This power point is useful to those who study chemistry in college and also useful for University students and also for PhD students
HSAB concept is an initialism for "hard and soft (Lewis) acids and bases". Also known as the Pearson acid-base concept, HSAB is widely used in chemistry for explaining stability of compounds, reaction mechanisms and pathways.
HSAB concept is an initialism for "hard and soft (Lewis) acids and bases". Also known as the Pearson acid-base concept, HSAB is widely used in chemistry for explaining stability of compounds, reaction mechanisms and pathways.
Theories of coordination compounds, CFSE, Bonding in octahedral and tetrahedral complex, color of transition metal complex, magnetic properties, selection rules, Nephelxeuatic effect, angular overlap model
Introductory PPT on Metal Carbonyls having its' classification,structure and applications.This is a basic level PPT specially prepared for UG/PG Chemistry students.
Classification Of Mechanisms, Ligand Substitution In Octahedral Complexes Without Breaking Metal-ligand Bond, Substitution Reaction In Square Planar Complexes, Factors Which Affect The Rate Of Substitution, Trans Effect (Labilizing Effect), Theories and applications Of Trans Effect
Theories of coordination compounds, CFSE, Bonding in octahedral and tetrahedral complex, color of transition metal complex, magnetic properties, selection rules, Nephelxeuatic effect, angular overlap model
Introductory PPT on Metal Carbonyls having its' classification,structure and applications.This is a basic level PPT specially prepared for UG/PG Chemistry students.
Classification Of Mechanisms, Ligand Substitution In Octahedral Complexes Without Breaking Metal-ligand Bond, Substitution Reaction In Square Planar Complexes, Factors Which Affect The Rate Of Substitution, Trans Effect (Labilizing Effect), Theories and applications Of Trans Effect
Acids and bases buffers ARRHENIUS CONCEPT
THE LEWIS CONCEPT-THE ELECTRON DONOR ACCEPTOR SYSTEM
BRONSTED-LOWRY CONCEPT (PROTON TRANSFER
THEORY
buffer action
ph scale
buffer capacity
acid base balance
isotonicity method
isotonic soltions
buffer solutions in pharmaceutical preparations
Acids are divided into two categories based on the ease with which they can donate protons to the solvent: i) strong acids and ii) weak acids
Strong acids are acids that completely dissociate in water. The reaction of an acid with its solvent (typically H2O) is called an acid dissociation reaction.
Weak acids are acids that dissociate partially in water. The extent of dissociation is given by the equilibrium constant.
Note:
A measure of the relative strength of an acid is: i) the equilibrium constant ka of the dissociation reaction of the acid in water (depends on temperature) ii) the degree of dissociation α of the acid in water (depends on the concentration of the acid an on temperature).
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
2. (1)Some Facts
Acid base properties are closely connected with the properties of solvents.
Solvent system definition applies in all cases where the solvent is capable of
autoionization whetherprotons are involved or not , i.e aprotic as well as
protic solvent .
Protic Solvent : protic solvent contains ionizable proton. (Eg- H₂O, HF)
Aprotic Solvent: aprotic solvent not have any ionizable proton. (Eg-
CCl₄,DMF,DMSO,THF)
According to the solvent system definition -
1. Acid is a substance that can generate the same cation as does the solvent
itself due to autoionization .
2. Similarly, Base can generate the anion part .
3. (2)Theory of autoionization
Studies on certain nonaqueous system, reveled that reactions in these solvents may be
explained by assuming auto-ionization of the solvent similar to water :
Substance furnishing H₃O⁺ ions in water act as acids in aqueous medium
Substance furnishing NH₃⁺ ion In liquid ammonia behaves as an acid
Similarly, substance furnishing NH₄⁻ ion in liquid ammonia are similar to those the
compounds giving OH⁻ ion in water.
1. Acids in liquid ammonia –NH₄Cl NH₄NO₃ etc.
2. Bases in liquid ammonia –KNH₂ NaNH₂ etc.
4. Examples of Autoionization
Other examples :
Autoionization of SO₂:
Acid in SO₂:
SOCl₂ → SO²⁺ + 2Cl⁻
Base in SO₂:
CaSO₃ → Ca²⁺ + 2SO₃²⁻
Neutralization :
SOCl₂ +CaSO₃ → CaCl₂+2SO₂
Geneal Formula of Autoionization
• AB +AB ⇌ A⁺ + AB₂⁻
• EXCEPTION
COCl₂ ⇌ COCl⁺ + Cl⁻
Acid:
AlCl₃+COCl₂ → COCl⁺ + AlCl₄
Base :
COCl₂ → Ca²⁺ + 2Cl⁻
NEUTRALISATION :
2COCl⁺AlCl₄⁻ + CaCl₂→Ca[AlCl₄]₂ + 2CaCO₂
5. (3)Strong and weak acid and bases
Strong acids dissociates completely into ions in water
HA (g or l) + H₂O (l) → H₃O⁺ (aq) + A⁻ (aq)
Weak acids dissociates very slightly into ions in water
HA (aq) + H₂O (l) ⇌ H₃O⁺ (aq) + A⁻ (aq)
acid dissociation constant
Kc = [H₃O⁺] [A⁻] /[H₂O] [HA]
Kc [H₂O] = Ka = [H₃O⁺] [A⁻] / [HA]
strong acid have higher [H₃O⁺] , larger Ka
weak acid have lower [H₃O⁺] , smaller Ka
**similarly we can also calculate Kb, Kb= [B⁺][OH⁻]/[BOH]
6. (4)Ionic products and nutral points
For water as a solvent the ionic product is
Kw=[H₃O⁺] ×[OH⁻]
At 25°C corresponding nutral point is Pᴴ =-log[H⁺]
= - 0.5 log [Kw]
Ionic product of any solvent AB is
AB + AB ⇌ A⁺ + AB₂⁻
K(AB) = [A⁺]×[AB₂⁻]
The neutral point is P(A) = -0.5 log [Kab] = 0.5 Pᵏᵃ
Ionic products and nutral points of
some non aqueous solvents:
7. (5)Demerits and Relativity of acidic
and basic character of CH₃COOH
Behavior of CH₃COOH In H₂O NH₃ and HF:
In water acetic acid behaves as a weak acid,
In liquid ammonia acetic acid behaves as a strong acid,
In HF asetic acid behaves as a base .
Demerits:
1. It places too much emphasis on Autoionization of solvent,
ignoring other physical and chemical properties of solvents.
2. Acid-base reaction occuring in absence of any solvent
cannot define by it.
