Lake Tahoe was formed by faulting and volcanic activity that created barriers to water flow. Glaciers later carved out the lake's distinctive shape. It is over 1,600 feet deep and surrounded by granite, basalt, and gneiss rock formed through igneous and metamorphic geologic processes. Ecosystems like the snow plant and beaver population have adapted to the lake's alpine environment.
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 .
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.
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.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Richard's aventures in two entangled wonderlandsRichard 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.
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.
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.
2. Introduction
This assignment identifies various natural and geologic features and
characteristics of the Lake Tahoe area. I gathered the information and data in
this assignment by performing research online, and from experiences that I
have had hiking and exploring Lake Tahoe Wilderness areas.
3. Formation of Lake Tahoe
• Long believed to be formed by a volcanic crater
collapsing, Lake Tahoe was formed by the rise
and fall of the landscape due to faulting
• Lave flowing from Mt. Pluto on the north shore
created a barrier at the Truckee river when
streams and snowfall filled the lake bed to
much greater heights.
• During the Pleistocene, large glaciers formed
and carved the western slopes, leaving
distinctive U-shaped valleys and bays on the
western shore
(USDA, N.D.)
4. Facts about Lake Tahoe
• 3rd deepest lake in North America, 10th deepest lake in the world
• 22 miles long, 22 miles wide
• Approximately 72 miles of shoreline
• Greatest measured depth is 1,645 ft.
• Bottom of the lake is actually lower than Carson Valley floor.
(USDA, N.D.)
5. Mount Tallac
• Elevation of 9,735 ft.
• Situated on the boundary between the granites of the Sierra Nevada
Batholith and earlier metamorphosed sedimentary rocks
• Known for the distinctive “cross” shape that faces towards the lake.
• “Tallac” is derived from the Washoe word meaning, “big mountain.”
(Summitpost, N.D.)
6. North American Beaver
• Almost hunted into extinction by early American settlers, the North American Beaver population is
currently stable, but it very elusive.
• Largest rodent in the United States
• Known best for it’s long, flat, black tail that is used to slap the water to alert other beavers of nearby
predators, and for balance.
• They have waterproof fur, webbed feet, and teeth that continually grow. Gnawing on trees shortens
their teeth, and many layers of protective enamel give them an orange color
• Beavers are known for the ability to build dams that extend underwater and have the potential to
change the surrounding landscape.
• Beavers are monogamous and mate around 3 years of age.
• Beavers can hold their breath underwater for 15 minutes and have transparent eyelids that allow them
to see underwater.
(National Wildlife Federation, N.D.)
7. Where did beavers evolve from?
• North American Beaver (Castor
Canandensis) evolved from the
European Beaver (Castor Fiber)
when they migrated to North
America From Asia 7.5 million
years ago
• Giant beavers known as
Castoroides existed in North
America during the Pleistocene
and were about twice the size of
beavers today
(Jorgensen, 2015)
8. Snow Plant (Sarcodes Sanguineae)
• Belongs to the Monotropaceae family
• Sarcodes Sanguineae is mycotrophic (has no
clorophyll) and get their nutrition from fungus
underneath the soil.
• This plant has a “parasitic” relationship with
conifers, providing water and minerals while
taking photosynthates from the mychorrhizae
(fungus roots) of the conifers.
(Guana, N.D.)
9. Igneous Granite
• Granite is an igneous rock type
• It is an intrusive igneous rock that formed
deep under the earther’s crust from
cooling magma
• Granite is commonly found in the areas
surrounding Lake Tahoe
• Granite contains mostly feldspar, but also
contain quartz and other minerals
(Encyclopedia Britannica, 2019)
10. Igneous Basalt
• Basalt is an Extrusive Igneous rock that
is formed from lava that reaches the
surface and then cools
• These rocks were formed by magma
from erupting volcanoes during the
Pleistocene.
• Basalt is typically low in silica and rich in
iron and magnesium.
(Encyclopedia Britannica, 2019)
11. Metamorphic gneiss
• Gneiss is a Metamorphic type rock
• Gneiss has well-developed foliation and
poorly developed cleavage and schistosity
• Gneiss typically displays parallel, somewhat
irregular banding which has little tendency to
split along planes.
(Encyclopedia Britannica, 2019)
12. Unconformities
• Cave rock is an example of an
Unconformity in Lake Tahoe
• You can observe the different
layers or strata as they are
layered
13. Law of Superposition
• Eagle Lake Buttress is an
example of the Law of
Superposition.
• The law of superposition states
that in a sequence of layered
rock, the younger rocks lies on
top of the older rocks.
• This is a principle that is applied
when it comes to relative dating
14. References
• U.S. Department of Agriculture. (N.D.) Geology of the Lake Tahoe Basin. Retrieved from https://www.fs.usda.gov/detail/ltbmu/learning/?cid=stelprdb5109570
• Guana, F.J. (N.D.) Snow Plant. Retrieved from: https://www.fs.fed.us/wildflowers/plant-of-the-week/sarcodes_sanguinea.shtml
• SummitPost. (2019). Mount Tallac. Retrieved from: https://www.summitpost.org/mount-tallac/150430
• National Wildlife Federation. (N.D.) American Beaver. Retrieved from: https://www.nwf.org/Educational-Resources/Wildlife-Guide/Mammals/American-Beaver
• Jorgensen, D. (2019). On the origins of the beaver. Retrieved from: http://dolly.jorgensenweb.net/nordicnature/?p=2099
• Editors of the Encyclopedia Britannica. (2019). Granite. Retrieved from: https://www.britannica.com/science/granite
• Editors of the Encyclopedia Britannica. (2019) Basalt. Retrieved from: https://www.britannica.com/science/basalt
• Editors of the Encyclopedia Britannia. (2019) Gneiss. Retrieved from: https://www.britannica.com/science/gneiss