This document provides an overview of photosynthesis, including:
- Photosynthesis converts sunlight, carbon dioxide, and water into oxygen and glucose through a two-step process in chloroplasts. Chloroplasts contain chlorophyll which absorbs light energy and the thylakoid membranes where the light-dependent reactions occur.
- Autotrophs like plants use photosynthesis to produce their own food, and release oxygen into the atmosphere as a byproduct. Most of Earth's oxygen comes from phytoplankton in the ocean.
- Photosynthesis is essential to life on Earth as it provides oxygen for humans and animals to breathe and produces glucose that sustains plant life.
The biotic elements that comprise an ecosystem fall into one of several trophic levels. The trophic level of an organism is its position in a food chain, the sequence of consumption and energy transfer through the environment.
The biotic elements that comprise an ecosystem fall into one of several trophic levels. The trophic level of an organism is its position in a food chain, the sequence of consumption and energy transfer through the environment.
The word cell is derived from the Latin word “cellula” which means “a little room”
It was the British botanist Robert Hooke who, in 1664, while examining a slice of bottle cork under a microscope, found its structure resembling the box-like living quarters of the monks in a monastery, and coined the word “cells”
This presentation describes the process of photosynthesis on plants. In order for plants to grow, they need inputs of Carbon dioxide (CO2), water and energy. The chemical process by which plants use these resources to manufacture glucose, the building blocks of plants, is called photosynthesis.
The word cell is derived from the Latin word “cellula” which means “a little room”
It was the British botanist Robert Hooke who, in 1664, while examining a slice of bottle cork under a microscope, found its structure resembling the box-like living quarters of the monks in a monastery, and coined the word “cells”
This presentation describes the process of photosynthesis on plants. In order for plants to grow, they need inputs of Carbon dioxide (CO2), water and energy. The chemical process by which plants use these resources to manufacture glucose, the building blocks of plants, is called photosynthesis.
For this assignment, we were instructed to create a powerpoint presentation of at least 12 slides that adequately covered an academic subject of our choice. All sources for media is cited in the work cited at the end of the presentation.
This presentation discusses the way energy flows and is distributed all throughout the ecosystem, from one member to another. This details how one organism becomes an essential necessity for another and how abiotic components play their role as supportive elements for life.
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.
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.
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.
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 .
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.
Astronomy Update- Curiosity’s exploration of Mars _ Local Briefs _ leadertele...
Photosynthesis Lecture for Lesson 1
1. +
Photosynthesis: Converting sunlight into chemical
energy
Students who demonstrate understanding can:
HS-LS1-5: Use a model to illustrate how photosynthesis transforms light energy into stored chemical
energy.
2. +
Where does the oxygen (O2) we
breathe come from?
O2 is produced by different
kinds of bacteria, algae, and
plants (including trees)
during photosynthesis.
About 25% of O2 comes from
land plants.
Most of Earth’s O2 comes
from the ocean.
Released from tiny ocean plants
called, phytoplankton.
3. +
Autotrophs and Photosynthesis
Called “self feeders” or
”producers”.
Organisms that can produce their
own food using light, water,
carbon dioxide, or other
chemicals.
Examples of autotrophs: green
plants, some algae, few bacteria.
Most autotrophs use
photosynthesis to make their
food.
4. +
Overview of Photosynthesis
Light energy gets converted
into chemical energy.
Chemical energy is stored in
the form of glucose (sugar).
Carbon dioxide, water, and
sunlight are used to produce
carbohydrates and oxygen.
Occurs in two stages:
Light Dependent Reactions
Light Independent
Reactions
NASA: Seeing
Photosynthesis From Space
5. +
Where Does Photosynthesis Take Place
in the Cell?
7. +
Closer Look at Chloroplast
Structures
Chlorophyll:
Allows plants to absorb energy
from light
Gives leaves their green color
Membrane Envelope:
Inner and outer membranes
Protects and keep chloroplast
structures enclosed.
Thylakoid membrane:
Internal membrane system
Flattened sac-like membrane
structures called thylakoids
Serve as the sites of conversion
of light energy to chemical
energy.
Granum
Dense layered stacks of
thylakoid sacs
Sites of conversion of light
energy to chemical energy.
Stroma
Dense fluid within the chloroplast
Lies inside the envelope but
outside the thylakoid membrane
Site of conversion of carbon
dioxide to carbohydrates
8. +
Two Processes of Photosynthesis
Light Dependent Reactions Light Independent Reactions
Location: Thylakoid Membrane
Reactants: Sunlight and water
(H2O)
End Products: ATP, NADPH,
and O2
Also called “Calvin Cycle” or
Dark Reactions
Location: Stroma
Reactants: ATP, NADPH, and
O2
End Products: Glucose
Remember:
Cells use ATP for energy
NADPH is a cofactor in reactions that acts as a reducing agent
11. +
Why is photosynthesis essential to life
on Earth?
Well..
Life can be sustained in plants.
Plants provide oxygen for
humans.
We BREATHE oxygen!
Without oxygen we cannot
survive!
Editor's Notes
Glucose is a type of sugar. The glucose gives plants energy and the plants can also use glucose to make cellulose, a substance they use to grow and build cell walls.
Here is a picture of a real chloroplast and a model. Notice the organelle has a double membrane (inner and outer) and has special structures inside. Remember chloroplasts are only found in plant cells!
The first part is called the light dependent reaction. This reaction happens when the light energy is captured and pushed into a chemical called ATP. Atmospheric oxygen is produced by the “splitting” of water. Notice how oxygen is released during the light dependent reaction and ATP and NADPH move into the second part of photosynthesis. In general, the second part of the process happens when the ATP is used to make glucose. Remember this is also referred to as the Calvin Cycle or light independent reaction. This process gets its name because sunlight in not directly involved with this cycle.
