Science 9 Module 5 Ecosystem: Life Energy Part 1
Summary
TLDRTeacher Josie's video offers an insightful exploration into the ecosystem's energy dynamics, focusing on photosynthesis and respiration. It explains how plants, as primary producers, harness sunlight to convert carbon dioxide and water into glucose and oxygen, a process vital for their growth and sustenance. The video delves into the mechanics of photosynthesis, detailing the light-dependent and light-independent reactions, and their significance in the food chain. It also touches on cellular respiration and metabolism, using key terms like ATP, NADPH, and chlorophyll to enhance understanding. Engaging questions and activities are included to test viewers' comprehension, making it an educational and interactive learning experience.
Takeaways
- 🌿 **Importance of Photosynthesis**: Photosynthesis is crucial for all life as it allows plants to convert light energy into chemical energy, providing sustenance for themselves and other organisms.
- 🔬 **Stages of Photosynthesis**: The process can be divided into two main stages: the light-dependent reactions that occur in the thylakoid membrane and the light-independent reactions or Calvin cycle that take place in the stroma.
- 🌱 **Plants as Producers**: Plants, along with certain algae and prokaryotes, are primary producers that capture sunlight and produce their own food, serving as the base of the food chain.
- 🍃 **Leaves in Photosynthesis**: Leaves are the primary organs for photosynthesis, with key parts like the epidermis, mesophyll, and stomata playing essential roles in the process.
- 🌞 **Light Energy Role**: Light energy is absorbed by chlorophyll and used to power the reactions of photosynthesis, highlighting the importance of sunlight for life on Earth.
- 💧 **Water's Role in Photosynthesis**: Water is a key reactant in photosynthesis, not only providing hydrogen for glucose production but also releasing oxygen as a byproduct.
- 🌱 **Chlorophyll's Function**: Chlorophyll within the chloroplasts is responsible for capturing light energy and initiating the light-dependent reactions of photosynthesis.
- 🔋 **Energy Storage in ATP and NADPH**: ATP and NADPH, produced during the light-dependent reactions, store energy that is later used in the Calvin cycle to fix carbon dioxide.
- 🔄 **Calvin Cycle's Efficiency**: The Calvin cycle operates through a series of reactions, requiring six turns to produce one glucose molecule, demonstrating the complexity of energy conversion in plants.
- 🌳 **Plants as Food Providers**: Plants are often referred to as 'great food providers' because they manufacture energy-rich glucose through photosynthesis, which is essential for the survival of animals and humans.
Q & A
What is the primary focus of the video by Teacher Josie?
-The video focuses on the concept of ecosystem life energy, explaining the basic features and the importance of photosynthesis and respiration in sustaining life.
Why are plants considered great food providers?
-Plants are considered great food providers because they produce their own food through photosynthesis and serve as the primary source of food for all consumers, including animals and humans.
What are the major stages in photosynthesis?
-Photosynthesis can be divided into two major stages: the light-dependent reaction, which occurs in the thylakoid membrane and requires light, and the light-independent reaction or carbon cycle, which takes place in the stroma of the chloroplast.
What is the role of chlorophyll in photosynthesis?
-Chlorophyll is the green pigment in plants that absorbs light energy from the sun, which is then used to power the chemical reactions of photosynthesis.
What are the functions of the different parts of a leaf in relation to photosynthesis?
-The upper and lower epidermis help retain water and regulate gas exchange through stomata. The mesophyll layer contains chloroplasts with chlorophyll for light absorption. The vascular bundles transport nutrients, and the stroma within chloroplasts is where the chemical reactions of photosynthesis occur.
How does the Calvin cycle contribute to the production of glucose in plants?
-The Calvin cycle uses the ATP and NADPH produced during the light-dependent reactions to fix carbon dioxide and produce glyceraldehyde 3-phosphate, which can be used to make glucose and other carbohydrates.
What is the significance of the electron transport chain in the light-dependent reaction of photosynthesis?
-The electron transport chain in the light-dependent reaction is significant as it facilitates the transfer of energized electrons, which leads to the production of ATP and NADPH, essential for the synthesis of glucose during the Calvin cycle.
What is the role of ATP in the process of photosynthesis?
-ATP, or adenosine triphosphate, is a high-energy molecule that stores energy produced during the light-dependent reactions of photosynthesis and is later used in the Calvin cycle to power the synthesis of glucose.
How does the process of photosynthesis help in the production of oxygen?
-During the light-dependent reactions of photosynthesis, water molecules are split, releasing oxygen gas into the atmosphere as a byproduct.
What is the significance of the abbreviations NAD, ATP, and FAD mentioned in the script?
-NAD stands for nicotinamide adenine dinucleotide, ATP for adenosine triphosphate, and FAD for flavin adenine dinucleotide. These are important molecules involved in energy transfer and electron transport during cellular respiration and photosynthesis.
Outlines
🌿 Introduction to Ecosystem and Energy
Teacher Josie introduces the concept of ecosystems and energy flow within them. The video is designed to educate about how organisms obtain energy from food and produce energy through processes like photosynthesis and respiration. Key questions are posed to ponder upon after the video, such as why plants are called great food providers and the parts of plants involved in photosynthesis. The script also introduces the concept of metabolism and the role of chlorophyll in plants. It explains the importance of producers like plants, algae, and certain protists that capture light energy from the sun and are considered autotrophs, producing their own food.
🌱 Understanding Photosynthesis
This section delves into the process of photosynthesis, explaining how plants use light energy from the sun and carbon dioxide to produce glucose and oxygen. The script describes the parts of a leaf involved in photosynthesis, including the epidermis, mesophyll, and chloroplasts. It details the light-dependent reactions occurring in the thylakoid membrane and the role of chlorophyll in absorbing light energy. The process of converting light energy into chemical energy through the electron transport chain and the production of ATP and NADPH are also explained. The script further discusses the light-independent reactions or the Calvin cycle, which uses ATP and NADPH to fix carbon dioxide and produce carbohydrates.
🔬 The Calvin Cycle and Its Significance
The third paragraph focuses on the Calvin cycle, the light-independent reactions of photosynthesis that occur in the stroma of the chloroplast. It explains the three phases of the cycle: carbon fixation, carbon dioxide reduction, and regeneration of RuBP. The Calvin cycle uses the ATP and NADPH produced during the light-dependent reactions to reduce carbon dioxide into glyceraldehyde 3-phosphate, which can then be used to make glucose, fatty acids, or glycerol. The script also outlines the chemical equation of the Calvin cycle and how multiple turns of the cycle are needed to produce one molecule of glucose.
📝 Summary and Activity on Photosynthesis
The final paragraph summarizes the process and products of the Calvin cycle and provides an activity to reinforce understanding. It includes a quiz with statements related to light-dependent and light-independent reactions, asking viewers to identify which processes are associated with each. The script ends with a call to action for viewers to like, share, subscribe, and turn on notifications for more educational content, thanking them for watching.
Mindmap
Keywords
💡Ecosystem
💡Photosynthesis
💡Respiration
💡Chlorophyll
💡Autotrophs
💡Metabolism
💡ATP (Adenosine Triphosphate)
💡NADPH
💡Calvin Cycle
💡Stomata
💡Chloroplast
Highlights
Introduction to the topic of ecosystem life energy and the importance of photosynthesis and respiration.
Key learning competency: Understanding the features and significance of photosynthesis and respiration.
Organisms need energy to sustain life, and this video focuses on how they obtain and produce it.
Plants are called 'great food providers' because they produce their own food through photosynthesis.
Photosynthesis occurs mainly in the leaves, with key parts like the epidermis, mesophyll, and stomata involved.
Chloroplasts in plant cells contain chlorophyll, which captures energy from sunlight.
Photosynthesis can be divided into two stages: the light-dependent reactions and the Calvin cycle.
Light-dependent reactions occur in the thylakoid membrane, where light energy is converted into chemical energy.
The Calvin cycle (light-independent reactions) occurs in the stroma and is responsible for producing glucose.
The chloroplast contains a double membrane, stroma, and thylakoids that are essential for photosynthesis.
Key molecules in the photosynthesis process include ATP, NADPH, and glucose.
Photosystem I and Photosystem II play a major role in the light-dependent reactions.
The Calvin cycle requires ATP and NADPH from the light-dependent reactions to produce G3P, a precursor to glucose.
The equation for photosynthesis: carbon dioxide + water + sunlight → glucose + oxygen.
Photosynthesis helps produce essential molecules like glucose, starch, and cellulose for plant growth and energy.
Transcripts
[Music]
hello everyone welcome to my channel
this is teacher josie that will give you
an idea about ecosystem life energy
the video focuses on achieving this
learning competency
different shade basic features and
importance of photosynthesis and
respiration
in this video you will learn that all
organisms need the energy to sustain
life you will focus on how the organisms
obtain energy from the food and how they
produce energy
here are some key questions for you to
ponder after finishing this video
why are plants called great food
providers
what are the parts of the plants
involved in photosynthesis
what are the major stages in
photosynthesis
let's recall your understanding of the
concepts of photosynthesis and cellular
respiration identify the word based on
the given description
the total chemical processes taking
place within the living system what do
you think is the answer
the answer is metabolism
the green coloring matter of plants
that is chlorophyll
let us first familiarize the different
abbreviation that we are going to
encounter in this study
nad
nicotinamide adenine binocular
biphosphate
nad means
nicotinamide adenine dioxide
atp means adenosine
triphosphate
bgal
phosphoglyceraldehyde
fad
1189 the nucleotide
adp means adenosine diphosphate
the main producers like plants
algae
certain protists and some prokaryotes
capture light energy from the sun for
their needs and to provide energy for
almost all life forms
these producers are considered as
self-feeders or autotrophs because they
produce their own food and sustain
themselves without consuming other
organisms in order to survive
if we look at the hierarchy of food
chain we can see that plants are in the
bottom parts which are considered as
primary source of food for all consumers
like animals including humans
if plants manufacture energy for animals
to use they should have a way to
recharge their nutrients
what is photosynthesis
photosynthesis is the process by which
plants use light energy from the sun and
carbon dioxide to produce glucose the
sugar molecules and oxygen that they use
for growth and nourishment
primarily photosynthesis takes place in
the leaves which are the main organs for
photosynthesis
the typical parts of the leaves include
the upper and lower epidermis
palisade nesophil
mesophyll spongy layer
vascular bundles
and stomata
the upper epidermis the outermost layer
which secretes a waxy substance called
cuticle
this cuticle helps retain water inside
the leaf cells
at the lower epidermis you will see some
openings
each opening is called stoma or stomata
this is where carbon dioxide enters
oxygen passes out
around the stoma is a pair of bin shaped
cells called guard cells
the guard cell is an epidermal cell
with chloroplast that regulates the
opening and flossing of the stomach
between the upper and lower epidermis
you can see layers of cells this is
called mesophyll layer which is composed
of polycyte
cells that are arranged like columns and
spongy cells which are loosely arranged
cells
these cells of organelles known as
chloroplasts that contains green
pigments which trap energy from the sun
the chloroplast is enclosed by a double
membrane in the outer membrane
and an inner membrane
between these membranes is a space
called stroma which is the liquid part
of the chloroplast
embedded in the stroma is a complex
network of stacked socks
each stack is called a granule
or
grana
each of those flattened sacks is called
this
thylakoids that contains green colored
pigments called chlorophylls that absorb
light
the equation used to explain
photosynthesis is as follows
carbon
dioxide and water
with sunlight produces
glucose and
oxygen
photosynthesis involves many steps but
it can be divided into two stages
one the light dependent reaction
and the second is carbon cycle
the light dependent reaction stage
occurs in the thylakoid membrane and
requires a continuous supply of light
during this reaction light energy is
absorbed by the chlorophyll and
converted into chemical energy
in order to plants to grow they need
carbon dioxide
water and energy
the chemical process by which plants use
these resources to manufacture glucose
is called photosynthesis
plants appear green because they reflect
yellow and green wavelengths of light
red and blue wavelengths of light are
absorbed by these pigments and provide
the energy that is used for
photosynthesis
the chemical reactions of photosynthesis
occur within plant cells known as
chloroplast
the light dependent reaction occur in
the thylakoid for conversion of light
energy to chemical energy
is initiated the reactions that
synthesize glucose the carbon cycle pour
in straw
the light dependent reaction stage
occurs in the thylakoid membrane and
requires a continuous supply of light
the chlorophyll is composed of two units
of light absorbing molecule namely the
photosystem 2 or ps2 and photosystem 1
ps1
the light dependent reaction begins when
ps2 receives light energy
the light energy is transferred to
chlorophyll reaction center causing
electrons in the reaction center to
become energized
the energized electrons escape ps2 and
moved an electron acceptor molecule
located in the electron transport chain
to replace the lost electrons in ps2
water is split releasing oxygen
two hydrogen ions and two electrons
the excited electrons
continue to move from photosystem 2 to
photosystem 1 through the electron
transport chain
a protein in the electron transport
chain pumps hydrogen ions from the
stroma into the thylakoid space
as electrons move between those
photosystems they lose energy
photosystem 1 absorb light and
re-energize the electron
the chemical called nadp
accepts the electron and hydrogen and
becomes
nadph
which is high energy molecule
as the hydrogen ions continue to build
up inside the thylakoid
atp synthase allows the hydrogen ions to
travel from the thylakoid to the stroma
by the fusion and captures the energy of
their movement by spinning and stores
that energy in atp
an enzyme found in the thylakoid
membrane uses energy of electrons from
both ps2 and ps1 to create more atp and
to stop the production of nadph
it is important to maintain the right
proportion of
nadph and atp which will be used in the
next phase of photosynthesis
in short
chlorophyll in photosystem 2
absorbs light and energizes an electron
a carrier molecule transports the
electron out and down the electron
transport chain a water molecule is
split
releasing a new electron into the system
and oxygen into the atmosphere
the chlorophyll in photosystem 1 absorbs
light energizing an electron a carrier
removes the electron and the electron
from ps2 replaces it the electron is
accepted by nadp
at the end of the transport chain the
gradient pushes ions through atp
synthase
driving atp synthesis
nadph
and atp go onto the calvin cycle
the second stage of photosynthesis is
the light independent reaction are
carbon cycle which occurs in this trauma
of the chloroplast
this series of complex reactions can be
divided into three phases
carbon fixation carbon dioxide reduction
and regeneration of rubp
the atp and nadph
formed during the light dependent
reactions are used in the stroma to fuel
the carbon cycle reactions
the calvin cycle consists of a series of
reactions that reduce carbon dioxide to
produce the carbohydrate
glyceraldehyde 3-phosphate
the cycle consists of three steps
the first of which is carbon fixation
in this step carbon dioxide is attached
to riboulus 1
5-by-phosphate resulting in a 6-carbon
molecule that splits into 2-3 carbon
molecules
the second step is a sequence of
reactions using electrons from nadph
and some of the atp to reduce carbon
dioxide
in the final step riboluse 1
5-biphosphate is regenerated
for every 3 turns of the cycle
5 molecules of glyceraldehyde
3-phosphate are used to reform 3
molecules of ribolus1 5-biphosphate
the remaining glyceraldehyde 3-phosphate
is then used to make glucose fatty acids
or glycerol
it takes two molecules of glyceraldehyde
3-phosphate
to make one molecule of glucose
phosphate
thus the calvin cycle has to run six
times to produce one molecule of glucose
these molecules can remove their
phosphate and add fructose to form
sucrose
the molecule plants used to transport
carbohydrates throughout their system
glucose phosphate is also the starting
molecule for the synthesis of starch and
cellulose
to sum the process and the products of
calvin cycle the overall chemical
equation of the face is the following
three carbon dioxide
plus
six
nadph plus
five water
plus
nine atp the product is
g3p plus
two hydrogen ions
plus
six nadp plus nine adp plus eight pi
pi stands for inorganic phosphate
six runs of the cycle are needed in
order to come up with one glucose
molecule as mentioned earlier the
surplus g3p which is produced by the
reactions could be used to form other
carbohydrates depending on the
necessities of the plants
did you understand
let's have an activity lights off
lightspot
right
on if the process pertains to light
dependent reaction and writes off if the
process pertains to light and dependent
reaction
number one
it is also known as the dark reaction of
photosynthesis
the answer is
off
2
primary acceptor of carbon is
photosystem 1 and photosystem 2.
the answer is on
sides of the process is in this trauma
the answer is
off
number four
photo recess of water does not pour
the answer is
of
number five
process type is both cyclic and
non-cyclic process
answer is
on
number six
it is a release of oxygen that gives off
aldehydes and hydrogen
upon dehydrogenation
the answer is
on
number seven
it is a process that converts solar
energy into chemical energy
the answer is on
number eight
it is a light dependent process
the answer is
one
nine
process type is cyclic only the answer
is off
number 10
primary acceptor of carbon is rubisco by
phosphate
the answer is off
do you have the same answer
good job
let's check your understanding
which best describes light independent
reactions
a they create energy rich atv and
nadph
b
they are the first phase of
photosynthesis
c they use carbon dioxide to make
proteins
d
they utilize the energy stored in atp
and nadph
comment below if you know the answer
that's all for today please don't forget
to like share subscribe and hit the
notification bell for more videos thank
you for watching bye
[Music]
thanks for watching
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