Atoms are composed of subatomic particles including electrons, protons, and neutrons. John Dalton developed atomic theory, proposing that all matter is composed of indivisible atoms that combine in simple whole number ratios. Atoms consist of a small, dense nucleus surrounded by electrons in energy levels. Rutherford's gold foil experiment revealed the small, dense nucleus at the atom's center. Niels Bohr incorporated quantum theory into atomic structure, proposing electrons orbit in discrete energy levels. The modern atomic model consists of a positively charged nucleus surrounded by electrons in quantized energy shells or orbitals.
460 BC - Greek philosopher proposes the existence of the atom
He pounded materials until he made them into smaller and smaller parts
He called them atoma which is Greek for “indivisible”.
460 BC - Greek philosopher proposes the existence of the atom
He pounded materials until he made them into smaller and smaller parts
He called them atoma which is Greek for “indivisible”.
Second-level Digital Divide and experiences of Schools and TeachersLiwayway Memije-Cruz
The second-level digital divide, is referred to as the production gap, and it describes the gap that separates the consumers of content on the Internet from the producers of content.
Science and technology studies, or science, technology and society studies (STS) is the study of how society, politics, and culture affect scientific research and technological innovation, and how these, in turn, affect society, politics and culture.
A hydrocarbon is a molecule whose structure includes only hydrogen and carbon atoms. Hydrocarbons form bonds with other atoms in order to create organic compounds.
Hydrocarbon derivatives are based on simple hydrocarbon compounds that contain only hydrogens and carbons. Hydrocarbon derivatives contain at least one element other than hydrogen or carbon, such as oxygen, nitrogen or one of the halogen atoms (elements in column 7A of the Periodic Table.
Organic reactions are chemical reactions involving organic compounds. Organic reactions are used in the construction of new organic molecules. The production of many man-made chemicals such as drugs, plastics, food additives, fabrics depend on organic reactions.
Organic chemistry involves the study of the structure, properties, composition, reactions, and preparation of carbon-containing compounds, which include not only hydrocarbons but also compounds with any number of other elements, including hydrogen (most compounds contain at least one carbon–hydrogen bond), nitrogen, oxygen, halogens, phosphorus, silicon, and sulfur.
This branch of chemistry was originally limited to compounds produced by living organisms but has been broadened to include human-made substances such as plastics. The range of application of organic compounds is enormous and also includes, but is not limited to, pharmaceuticals, petrochemicals, food, explosives, paints, and cosmetics.
Organic chemistry is the study of the structure, properties, composition, reactions, and preparation of carbon-containing compounds, which include not only hydrocarbons but also compounds with any number of other elements, including hydrogen (most compounds contain at least one carbon–hydrogen bond), nitrogen, oxygen,
Science and technology studies, or science, technology and society studies (STS) is the study of how society, politics, and culture affect scientific research and technological innovation, and how these, in turn, affect society, politics and culture.
Isomers are molecules with the same molecular formula, but different structural or spatial arrangements of the atoms within the molecule. The reason there are such a colossal number of organic compounds which is more than 10 million is partly due to isomerism.
Apportionment is Apportionment involves dividing something up, just like fair division.
Voting is a method for a group, such as, a meeting or an electorate to make a collective decision or express an opinion, usually following discussions, debates or election campaigns.
Lipid metabolism entails the oxidation of fatty acids to either generate energy or synthesize new lipids from smaller constituent molecules. Lipid metabolism is associated with carbohydrate metabolism, as products of glucose (such as acetyl CoA) can be converted into lipids.
A Hamiltonian path is a path that visits each vertex of the graph exactly once.
A Hamiltonian circuit is a path that uses each vertex of a graph exactly once and returns to the starting vertex.
Carbohydrate metabolism involves the different biochemical processes responsible for the formation, breakdown, and interconversion of carbohydrates in living organisms.
A graph is a diagram displaying data which show the relationship between two or more quantities, measurements or indicative numbers that may or may not have a specific mathematical formula relating them to each other.
Every organism is composed of several different types of human body tissue. The human body tissue is another way of describing how our cells are grouped together in a highly organized manner according to specific structure and function. These groupings of cells form tissues, which then make up organs and various parts of the body.
Reproduction means producing offspring that may or may not be exact copies of their parents. It is a part of a life cycle, which is a series of events wherein individuals grow, develop, and reproduce according to a program of instructions encoded in DNA, which they inherit from their parents. When cells divide, each daughter cell receives a complete copy of DNA and enough cytoplasmic machinery to start up its own operation. DNA contains the blueprints for making different proteins.
.Enzymes are proteins that catalyze or speed up chemical reactions. They also help digest the foods we eat food and heal our wounds. They play major roles in respiration, making proteins, and DNA replication..
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.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
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.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
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 .
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.
3. State of the Environment:
Issues and Concerns
Democritus (c. 460 – c. 370 BC) an ancient Greek pre-
Socratic philosopher
He developed the
first philosophical
statements relating
to an idea similar to
atoms
He was the one
who coined the
term atomos, which
mean “uncuttable”
4. John Dalton: (6 September 1766 – 27 July 1844) an English
chemist, meteorologist and physicist
determined the usefulness
of atoms.
first to realize that the
nature and properties of
atoms could be used to
explain the Law of Definite
Composition of all
substances developed
earlier by Proust and the
way and the proportions in
which substances react
with one another.
5. The atoms are composed of subatomic particles:
Electrons have a negative
charge and are the least
massive of the three;
Protons have a positive
charge and are about
1836 times more massive
than electrons; and
Neutrons have no charge
and are about 1839 times
more massive than
electrons.
6. Assumptions of Dalton’s Atomic Theory
All matter is made up of minute, discreet, indivisible, and
indestructible particles called atoms.
Atoms of the same element are chemically alike: atoms of
different elements are chemically different. in particular, the
atoms of one element have a different mass than those of
other elements.
When atoms combine to form compounds or when such
combination of atoms decomposes, each individual atom
retain its identify.
When atoms combine they do so in small numbers ratios.
7. Illustration of Dalton’s Theory
Atoms of the same
element are
chemically alike:
atoms of different
elements are
chemically different. in
particular,the atoms of
one element have a
different mass than
those of other
elements.
8. Law of Definite Composition
When atoms combine to form compounds or
when such combination of atoms decomposes,
each individual atom retain its identify.
9. Rutherford’s Experiment
He performed the
experiment on bombarding
gold foil with alpha
particles. They observed
that most (about 99.99%) of
the particles passed
through the film following a
straight path, while some
were deflected at large
angles and few bounced
back.
10. Based on the results, Rutherford proposed the
following
1. That the atom consists of a large empty space that explains
why most of the particles went straight through the film.
2. That the atom consists of a very small region where its
positive electricity is concentrated, hence, heavy. The
particles that bounced back were presumed to have hit this
region.
3. Those, which deflected, approached the positive nucleus;
hence, there was repulsion since the alpha particles were
also positive.
The above reasons describe the central part of the atom, called
nucleus, to be with a very small volume yet a massive one.
11. known for his foundational
contributions to further
understanding of the atomic
structure and quantum theory.
Niel Bohr (1885 – 1962) a Danish physicist
12. Isotopes
Atoms of the same element can have the same atomic number but
will differ in their atomic masses and these are called isotopes. The
first isotopes discovered were those of neon by Thomson and Aston
in 1912-1913. The mass spectrograph is a precise instrument used
to determine the atomic masses to 1 part in 10,000.
13. Characteristics of an Atom
All elements are observed to be electrically neutral, despite the presence of
electrically charged particles in atoms. The number of positive protons in the
nucleus of an atom is equal to the number of electrons surrounding the
nucleus.
Since elements differ from one another, their atoms must differ structurally.
Each element has an atomic number, the atomic number is equal to the
number of electrons revolving about the nucleus of the atom. Since atoms
are electrically neutral, the atomic number also equals the number of protons
present in the nucleus of an atom.
Equal number of atoms of different elements weighed under the same
conditions has a different weight. Atoms of different elements have different
atomic weights, the atomic weight of an atom is equal to the sum of the
number of protons and the number of neutrons in the nucleus of an atom.
Thus, all of the weight of an atom comes from its nucleus. Atomic weights
are relative, they do not give the number of grams that an atom weights, but
they merely tell how much heavier or lighter an atom of one element is than
another.
14. Distribution of Electrons
Electrons revolve around the nucleus of an atom in
a definite pattern. Groups of electrons maintain
definite average distances from the nucleus forming
shell or energy levels of electrons surrounding the
nucleus. Each shell is capable of containing a
definite number of electrons, the number increasing
in distance from the nucleus increases. Letters – k,
l, m, n, o, and p starting with the shell nearest the
nucleus, designates the shells. The maximum
number of electrons in any shell can be calculated
from the relationship:
Number = 2s Where:
Number = maximum number of electrons possible in
the shell
S = the number of the shell (K=1, I=2. m=3, etc)
15. Sublevels
The energy levels are further subdivided into
sublevels designated by the letters s, p, d,
f, g … (in alphabetical order), the number
of which corresponds to the number of the
energy level.
Each sublevel has a set of orbital, which
are of equal energy.
K (n=1) one sublevel: 1s
L (n=2) two sublevels: 2s and 2p
M (n=3) three sublevels: 3s, 3p, and 3d
s = 2 electrons
p = 6 electrons
d = 10 electrons
f = 14 electrons
16. Orbital is the home of the electrons or the region of space where the
probability of finding the electrons is greatest.
17. Rules in building up the electronic configuration
The number of electrons entering the atom must be equal
to its atomic number, z, and the number of protons. Thus,
the atom is neutral.
No more than 2 electrons with opposite spins can enter any
single orbital (Pauli’s Exclusion Principle.)
When there are orbitals of the same kind of energy, the
electrons occupy the equivalent orbitals singly to the
maximum and with their spins parallel (Hund’s Rule).
The opposite spin may be represented by arrows pointing
upwards and downwards.
18. Wave Mechanics/Quantum Mechanics or Orbital
Theory
Light exhibitsdual wave-particleproperties. Interferenceand
diffraction patternsformed when light passesthrough slitscan only
beexplained by theaddition of waves. Discontinuousemission of
light from hot bodiescan only beexplained by particle-likephotons
of emitted light. Louis deBrogliereasoned that if light can exhibit
waveand particleproperties, then tiny moving particlesof matter
might also exhibit waveproperties.
19. Quantum Numbers
The Principal Quantum Number (n) is associated with the distance
of the electron from the nucleus and it determines the gross energy of
the electron.
The Second Quantum Number (Azimuthal Quantum Number) (I)
gives the shape of the orbital. It has integral values from 0 to n-1.
The Third Quantum Number (Magnetic Quantum Number) (m )
describes the orientation of the orbital in space. The integral values
may be l1, l-1, l-2 down to -l. Positive values of m describe orientation
in the direction of applied magnetic field while negative values refer to
orientation in the opposite direction.
The Fourth Quantum Number is the electron spin quantum number
(m ). It describes the spinning of the electron on its axis. It can have a
clockwise spin or counter clockwise spin.
Pauli’s Exclusion Principle states that no two electrons can have
the same set of four quantum numbers.
22. Exercise: C.HOPKINS CaFe Mighty good in a pinch of salt)
Element At.
no
At.
mass e _
p+ n0 Atomic
Structure
n
G P Valence Nature
23. Self-Progress Test
What is the modern atomic theory?
What are the main parts of an atom? Be able to describe each of the particles.
What is a shell or energy level?
How are shells or energy levels designated?
Define the following: a.orbital b.Quantum Mechanics c. Isotopes d. Atomic Number
e. Atomic Weight
describe Neil Bohr's Atomic Model
Explain the Quantum Number Theory.
Draw diagrams to show the distribution of electrons protons, and neutrons of atoms
of helium, neon, argon, krypton and radon.
What is the Heisenberg’s Uncertainly Principle? Why is it applicable to electrons
but not a moving vehicle?
Write the electronic configurations of the following: Carbon, Magnesium,
Potassium, Calcium and iron.