Week 2 OverviewLast week, we studied the relationship between .docxmelbruce90096
Week 2 Overview
Last week, we studied the relationship between acceleration, velocity, displacement, and time. Acceleration in an object is caused by the force acting on it. This week, we'll study the relationship between force and acceleration. Central to this study are the laws of motion that Isaac Newton discovered in the 17th century.
You must have observed in daily life that when you apply brakes to a car, it takes some time before the car stops completely. The speed with which a train moves depends on the amount of force applied by the engine. A ball thrown at a wall bounces back. Newton's laws help you understand the motion of day-to-day objects and explain all this phenomena. These laws can also help you create realistic graphic animations!
Have you ever walked on slippery surfaces? If so, you would have realized how difficult it is to walk on them. Slippery surfaces have less friction, which makes it difficult to walk. In fact, surface transportation would be impossible without friction. This week, we take a closer look at this important force. We will use Newton's laws to analyze problems involving friction.
Newton’s First Law
What are Forces?
Forces are the result of the interaction between bodies. In simple words, a force is the push or pull acting on an object. For example, you exert a force on a rope to pull an object, and the rope pulls the object.
Here, we need a transition between the definition of forces and Newton’s Laws. We also need a couple of examples of how to draw a force diagram.
The Law of Inertia
Newton's first law of motion explains the relation between the force applied on an object and its motion.
The law states that:
An object continues to remain in a state of rest or of uniform motion in a straight line unless compelled by an external force to act otherwise.
This means that an object prefers to remain in a state of rest or uniform motion; in order to change the state it's in you need to apply force to it. Further, an object will always resist the force applied to it. The property of an object to resist an external force is called inertia, and for this reason, Newton's first law is called the law of inertia.
If you slide an object on a smooth floor with a given speed, the distance it moves depends upon the friction between the object and the floor. The smoother the floor, the greater the distance traveled by the object. The object eventually stops because of the external force of friction.
A force is required to change the velocity of a body. To understand this statement first recall from your study of kinematics that velocity is a vector with a magnitude (speed) and a direction. In the absence of a force, both speed and direction are constant. When a force acts on an object, it changes the speed, direction, or both of the objects.
There is no basic difference between an object at rest and an object in uniform motion; rest and uniform motion are relative terms. An object at rest with respec.
Gravity The importance of Gravity What if gravity is too strongMervatMarji2
Directly proportional to the product of the masses of the objects being attracted
Inversely proportional to the distance between the objects squared
𝐹=𝐺 𝑚1𝑚2/𝑑^2
Week 2 OverviewLast week, we studied the relationship between .docxmelbruce90096
Week 2 Overview
Last week, we studied the relationship between acceleration, velocity, displacement, and time. Acceleration in an object is caused by the force acting on it. This week, we'll study the relationship between force and acceleration. Central to this study are the laws of motion that Isaac Newton discovered in the 17th century.
You must have observed in daily life that when you apply brakes to a car, it takes some time before the car stops completely. The speed with which a train moves depends on the amount of force applied by the engine. A ball thrown at a wall bounces back. Newton's laws help you understand the motion of day-to-day objects and explain all this phenomena. These laws can also help you create realistic graphic animations!
Have you ever walked on slippery surfaces? If so, you would have realized how difficult it is to walk on them. Slippery surfaces have less friction, which makes it difficult to walk. In fact, surface transportation would be impossible without friction. This week, we take a closer look at this important force. We will use Newton's laws to analyze problems involving friction.
Newton’s First Law
What are Forces?
Forces are the result of the interaction between bodies. In simple words, a force is the push or pull acting on an object. For example, you exert a force on a rope to pull an object, and the rope pulls the object.
Here, we need a transition between the definition of forces and Newton’s Laws. We also need a couple of examples of how to draw a force diagram.
The Law of Inertia
Newton's first law of motion explains the relation between the force applied on an object and its motion.
The law states that:
An object continues to remain in a state of rest or of uniform motion in a straight line unless compelled by an external force to act otherwise.
This means that an object prefers to remain in a state of rest or uniform motion; in order to change the state it's in you need to apply force to it. Further, an object will always resist the force applied to it. The property of an object to resist an external force is called inertia, and for this reason, Newton's first law is called the law of inertia.
If you slide an object on a smooth floor with a given speed, the distance it moves depends upon the friction between the object and the floor. The smoother the floor, the greater the distance traveled by the object. The object eventually stops because of the external force of friction.
A force is required to change the velocity of a body. To understand this statement first recall from your study of kinematics that velocity is a vector with a magnitude (speed) and a direction. In the absence of a force, both speed and direction are constant. When a force acts on an object, it changes the speed, direction, or both of the objects.
There is no basic difference between an object at rest and an object in uniform motion; rest and uniform motion are relative terms. An object at rest with respec.
Gravity The importance of Gravity What if gravity is too strongMervatMarji2
Directly proportional to the product of the masses of the objects being attracted
Inversely proportional to the distance between the objects squared
𝐹=𝐺 𝑚1𝑚2/𝑑^2
Use the given information and the theorems you have learned to show that r || s.
A carpenter is creating a woodwork pattern and wants two long pieces to be parallel. m1= (8x + 20)° and m2 = (2x + 10)°. If x = 15, show that pieces A and B are parallel.
Recall that the converse of a theorem is found by exchanging the hypothesis and conclusion. The converse of a theorem is not automatically true. If it is true, it must be stated as a postulate or proved as a separate theorem.
Refer to the diagram. Use the given information and the theorems you have learned to show that r || s.
What if…? Suppose the corresponding angles on the opposite side of the boat measure (4y – 2)° and (3y + 6)°, where
y = 8. Show that the oars are parallel
A line through the center of the horizontal piece forms a transversal to pieces A and B.
Use the given information and the theorems you have learned to show that r || s.
Use the given information and the theorems you have learned to show that r || s.
A carpenter is creating a woodwork pattern and wants two long pieces to be parallel. m1= (8x + 20)° and m2 = (2x + 10)°. If x = 15, show that pieces A and B are parallel.
Recall that the converse of a theorem is found by exchanging the hypothesis and conclusion. The converse of a theorem is not automatically true. If it is true, it must be stated as a postulate or proved as a separate theorem.
Refer to the diagram. Use the given information and the theorems you have learned to show that r || s.
What if…? Suppose the corresponding angles on the opposite side of the boat measure (4y – 2)° and (3y + 6)°, where
y = 8. Show that the oars are parallel
A line through the center of the horizontal piece forms a transversal to pieces A and B.
Use the given information and the theorems you have learned to show that r || s.
Use the given information and the theorems you have learned to show that r || s.
A carpenter is creating a woodwork pattern and wants two long pieces to be parallel. m1= (8x + 20)° and m2 = (2x + 10)°. If x = 15, show that pieces A and B are parallel.
Recall that the converse of a theorem is found by exchanging the hypothesis and conclusion. The converse of a theorem is not automatically true. If it is true, it must be stated as a postulate or proved as a separate theorem.
Refer to the diagram. Use the given information and the theorems you have learned to show that r || s.
What if…? Suppose the corresponding angles on the opposite side of the boat measure (4y – 2)° and (3y + 6)°, where
y = 8. Show that the oars are parallel
A line through the center of the horizontal piece forms a transversal to pieces A and B.
Use the given information and the theorems you have learned to show that r || s.
Use the given information and the theorems you have learned to show that r || s.
A carpenter is creating a woodwork pattern and wants two long pieces to be parallel. m1= (8x + 20)° and m2 = (2x + 10)°. If x = 15, show that pieces A and B are parallel.
Recall that the conver
hssb0704t_powerpresDNA as the transforming principle..pptMervatMarji2
Avery performed three tests on the transforming principle.
Qualitative tests showed DNA was present.
Chemical tests showed the chemical makeup matched that of DNA.
Enzyme tests showed only DNA-degrading enzymes stopped transformation.
Hershey and Chase confirm that DNA is the genetic material.
• Hershey and Chase studied viruses that infect bacteria, called bacteriophages.
• Tagged DNA was found inside the bacteria; tagged proteins were not.
They tagged viral DNA with radioactive phosphorus.
They tagged viral proteins with radioactive sulfur.
• Tagged DNA was found inside the bacteria; tagged proteins were not.
DNA structure is the same in all organisms.
• DNA is composed of four types of nucleotides.
• DNA is made up of a long chain of nucleotides.
Each nucleotide has three parts:
₋ a phosphate group.
₋ a deoxyribose sugar.
₋ a nitrogen-containing base
The nitrogen containing bases are the only difference in the four nucleotides.
Scientists Chargaff found:
The amount of adenine in an organism approximately equals the amount of thymine.
The amount of cytosine roughly equals the amount of guanine.
A=T C=G Chargaff’s rules
Watson and Crick determined the three-dimensional structure of DNA by building models.
They realized that DNA is a double helix that is made up of a sugar-phosphate backbone on the outside
with bases on the inside.
Watson and Crick’s discovery was built on the work of Rosalind Franklin and Erwin Chargaff.
₋ Franklin’s x-ray images suggested that DNA was a double helix of even width.
₋ Chargaff’s rules stated that A=T and C=G.
Nucleotides always pair in the same way.
The base-pairing rules show how nucleotides always pair up in DNA.
Because a pyrimidine (single ring) pairs with a purine (double ring), the helix has a uniform width.
A pairs with T
C pairs with G
The backbone is connected by covalent bonds.
The bases are connected by hydrogen bonds.
• Proteins carry out the process of replication.
• DNA serves only as a template.
• Enzymes and other proteins do the actual work of replication.
₋ Enzymes unzip the double helix.
₋ Free-floating nucleotides form hydrogen bonds with the template strand.
₋ DNA polymerase enzymes bond the nucleotides together to form the double helix.
₋ Polymerase enzymes form covalent bonds between nucleotides in the new strand.
₋ Two new molecules of DNA are formed, each with an original strand and a newly formed strand.
• Two new molecules of DNA are formed, each with an original strand and a newly formed strand.
• DNA replication is semiconservative.
Replication is fast and accurate.
DNA replication starts at many points in eukaryotic chromosomes.
There are many origins of replication in eukaryotic chromosomes.
DNA polymerases can find and correct err
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 .
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.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
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.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
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.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
Nucleic Acid-its structural and functional complexity.
Section 4.3 Newton.docx
1. Section 3 Newton’s Second and Third Laws
Newton’s Second Law
The acceleration of an object is directly proportional to the net force acting on the
object and inversely proportional to the object’s mass.
net force = mass acceleration
ΣF = ma
ΣF represents the vector sum of all external forces acting on the object, or the net
force.
Newton’s Third Law
• If two objects interact, the magnitude of the force exerted on object 1 by
object 2 is equal to the magnitude of the force simultaneously exerted on
object 2 by object 1, and these two forces are opposite in direction.
• In other words, for every action, there is an equal and opposite reaction.
• Because the forces coexist, either force can be called the action or the
reaction.
Action and Reaction Forces
• Action-reaction pairs do not imply that the net force on either object is zero.
• The action-reaction forces are equal and opposite, but either object may still
have a net force on it.
Consider driving a nail into wood with a hammer. The force that the nail exerts on
the hammer is equal and opposite to the force that the hammer exerts on the nail.
But there is a net force acting on the nail, which drives the nail into the wood.
