PHOTOSYNTHESIS: CALVIN CYCLE || Grade 9 Science _ BIOLOGY
Summary
TLDRThis educational video delves into the light-independent reaction of photosynthesis, known as the Calvin Cycle. It explains how plants convert carbon dioxide and water into glucose using ATP and NADPH from the light-dependent reaction. The Calvin Cycle, named after Nobel laureate Melvin Calvin, occurs in the chloroplast stroma and consists of three stages: carbon fixation, reduction, and regeneration. The video uses an interactive simulation to illustrate these stages, concluding with a summary of photosynthesis, emphasizing the conversion of light energy into chemical energy stored in glucose.
Takeaways
- πΏ Photosynthesis is a process where plants make their own food using light energy, carbon dioxide, and water.
- π¬ The process involves two stages: the light-dependent reaction and the light-independent reaction, also known as the Calvin cycle.
- π The Calvin cycle is named after Melvin Calvin, who won the 1961 Nobel Prize for his work on this set of chemical reactions.
- π± The Calvin cycle occurs in the chloroplast stroma and is initiated after the light-dependent reaction, which provides ATP and NADPH.
- β‘οΈ The cycle has three stages: carbon fixation, reduction, and regeneration, each catalyzed by different enzymes.
- π Carbon fixation involves the combination of CO2 with RuBP (ribulose bisphosphate) to form an unstable 6-carbon compound, which then splits into two 3-PGA (3-phosphoglycerate) molecules.
- β‘οΈ The reduction phase uses ATP and NADPH to convert 3-PGA into G3P (glyceraldehyde 3-phosphate), which involves the enzyme glyceraldehyde 3-phosphate dehydrogenase.
- π The regeneration stage involves using G3P to regenerate RuBP, allowing the cycle to continue, with energy from ATP.
- π± For every six CO2 molecules that enter, two molecules of glucose are produced, and the rest are used to regenerate RuBP for the next cycle.
- π The Calvin cycle is crucial for converting inorganic carbon into organic compounds like glucose, which are essential for plant growth and energy storage.
Q & A
What is the meaning of the term 'photosynthesis'?
-Photosynthesis means to put together by light, referring to the process where plants make their own food using light energy.
What are the raw materials needed for photosynthesis?
-The raw materials needed for photosynthesis are carbon dioxide and water.
What are the products of the light-dependent reaction in photosynthesis?
-The products of the light-dependent reaction are ATP, NADPH, and oxygen.
Who is the Calvin cycle named after and why?
-The Calvin cycle is named after Melvin Calvin, who won the 1961 Nobel Prize for working out the complex set of chemical reactions involved in this cycle.
Where does the Calvin cycle occur in a plant cell?
-The Calvin cycle occurs in the chloroplast stroma of plant cells, just after the light reaction of photosynthesis.
What are the three stages of the Calvin cycle?
-The three stages of the Calvin cycle are carbon fixation, reduction, and regeneration.
What is the role of ATP and NADPH in the Calvin cycle?
-ATP provides the energy for the Calvin cycle, and NADPH provides the reducing ability, both of which are supplied by the light-dependent reactions of photosynthesis.
How does carbon dioxide enter the Calvin cycle?
-Carbon dioxide enters the Calvin cycle by diffusing into the stroma of the chloroplast and combining with RuBP (ribulose bisphosphate).
What is the enzyme that catalyzes the carbon fixation stage of the Calvin cycle?
-The enzyme that catalyzes the carbon fixation stage of the Calvin cycle is RuBisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase).
What is the role of G3P (glyceraldehyde 3-phosphate) in the Calvin cycle?
-G3P is the final product of the Calvin cycle, with one molecule being used to form glucose and the others being recycled to regenerate RuBP for the continuation of the cycle.
How does the Calvin cycle regenerate RuBP?
-The Calvin cycle regenerates RuBP by using five G3P molecules, which are converted back into RuBP using energy from ATP.
Outlines
πΏ Introduction to the Calvin Cycle
This paragraph introduces the Calvin cycle, also known as the light-independent reaction of photosynthesis. It explains that the Calvin cycle occurs in the chloroplast stroma and is named after Melvin Calvin, who won the 1961 Nobel Prize for his work on this process. The cycle is dependent on the ATP and NADPH produced during the light-dependent reaction of photosynthesis. The paragraph outlines the three stages of the Calvin cycle: carbon fixation, reduction, and regeneration. It describes the first stage, carbon fixation, where carbon dioxide enters the chloroplast and combines with RuBP (ribulose bisphosphate) to form an unstable six-carbon compound, which then splits into two three-carbon molecules of 3-phosphoglycerate. The enzyme Rubisco plays a crucial role in this phase.
π¬ The Calvin Cycle's Three Phases
The second paragraph delves deeper into the Calvin cycle's three phases. It begins with the reduction phase, where the three-carbon molecules from carbon fixation are converted into glyceraldehyde-3-phosphate (G3P) using ATP and NADPH from the light-dependent reaction. The paragraph explains the role of the enzyme glyceraldehyde-3-phosphate dehydrogenase and how NADPH acts as an electron donor. It then moves on to the regeneration phase, where five of the G3P molecules are used to regenerate RuBP, allowing the cycle to continue. The paragraph concludes with a summary of the Calvin cycle's function in converting carbon dioxide into glucose using the energy from ATP and NADPH, and it invites viewers to use an interactive simulation for a better understanding. It also provides a brief overview of photosynthesis, highlighting the light reaction's role in producing ATP and NADPH, and the Calvin cycle's role in synthesizing glucose.
Mindmap
Keywords
π‘Photosynthesis
π‘Chlorophyll
π‘Carbon Dioxide
π‘Calvin Cycle
π‘ATP
π‘NADPH
π‘Carbon Fixation
π‘Reduction Phase
π‘Regulation
π‘Rubisco
π‘Glucose
Highlights
Photosynthesis is a life-dependent reaction that occurs inside leaves where plants make their own food.
The process of photosynthesis involves raw materials such as carbon dioxide and water.
The chemical equation for photosynthesis is carbon dioxide plus water equals glucose and oxygen using light energy.
Photosynthesis has two stages: the light-dependent reaction and the light-independent reaction (Calvin cycle).
The light-dependent reaction produces ATP, NADPH, and oxygen.
The Calvin cycle is named after Melvin Calvin, who won the 1961 Nobel Prize for his work on this process.
The Calvin cycle occurs in the chloroplast stroma and is aided by ATP and NADPH from the light reaction.
There are three stages in the Calvin cycle: carbon fixation, reduction, and regeneration.
Carbon dioxide fixation involves the combination of CO2 with RuBP (ribulose diphosphate) to form an unstable six-carbon compound.
The reduction phase uses ATP to convert phosphoglycerate into glyceraldehyde 3-phosphate (G3P) with NADPH acting as an electron donor.
In the regeneration stage, G3P molecules are used to regenerate RuBP, allowing the cycle to continue.
The Calvin cycle can produce glucose and other organic compounds from G3P.
The interactive simulation provided visualizes the three phases of the Calvin cycle: carbon fixation, reduction, and regeneration of RuBP.
Rubisco is the enzyme that catalyzes the carbon fixation stage of the Calvin cycle.
G3P is the final product of the Calvin cycle, with one molecule used for glucose and others for regenerating RuBP.
The light reaction converts light energy into chemical energy stored in ATP and NADPH, releasing oxygen as a byproduct.
The Calvin cycle combines carbon from CO2 with chemical energy to produce glucose.
The lesson concludes with a summary of photosynthesis, highlighting the roles of the light reaction and the Calvin cycle.
Transcripts
[Music]
good day Learners Welcome to our new
lesson in our previous lesson we talk
about photosynthesis specifically the
life dependent reaction it happens
inside the leaves where plants make
their own food through the process of
photosynthesis photosynthesis means to
put together by light so in the process
of photosynthesis they will need raw
materials such as carbon dioxide and
water now here are the chemical equation
for photosynthesis carbon dioxide plus
water putting together through light
energy inside the chlorophyll to form
glucose and oxygen now the overall
product of light dependent reaction ATP
nadph and oxygen again there are two
stages of photosynthesis the light
dependent reaction and the light
independent reaction we already
discussed the light dependent reaction
in our previous video and for this video
we're going to talk about the light
independent reaction or what we called
the Calvin cycle Calin cycled is named
after Melvin Calvin who won a 1961 Nobel
Prize for working out this complex set
of chemical reaction Calin cycle occurs
in the chloroplast troma just after
completing the light reaction of
photosynthesis the light reaction helps
Calin cycle by providing ATP which is
its source of energy and nadph for
reducing ability now there are three
stages of Calin cycle stage one is the
carbon fixation stage two the reduction
and stage three is the Regeneration now
let's start with stage one which is
carbon dioxide fixation carbon dioxide
enters through the stomata then diffuse
into the stroma of the chloroplast
carbon dioxide combined with rudp 5 or
ribulose diphosphate to form an unstable
six carbon or what we call the
rp6 in other books or reference rudp 5
is also called as five carbon molecule
ribulose biphosphate carbon dioxide
combined with rudp 5 to for form an
unstable six carbon dioxide or R udp6
rudp 5 is also known as carbon dioxide
acceptor now rp6 splits into two
molecules or phosphoglycerate or three
phosphoglyceric acid or three PGA now
this stage of Calvin cycle is catalyzed
by the enzymes rubisco now for stage two
the reduction phase using the energy
from ATP three PGA molecules are
converted into three carbon sugar or
glycer alide three phosphate or g3p or
phosphoglyceride or pigal this stage
involves the enzyme of glycer alide
three phosphate dehydrogenase in which
nadph from light reaction acts as a
donor or acts as electron donor now here
are the summary of the change of PGA to
pigal PGA plus ATP Plus nadph become
pigal plus nadp plus ADP nadp and ADP
are available again for conversion
during cyclic and noncyclic reaction now
for stage three which is the final stage
it starts with
g3p some g3p or pigal is utilized in
making glucose well others are recycled
to continue the cycle by combining with
a carbon acceptor or rp5 assuming that
there are six carbon dioxide enters the
reaction 12 pigal will be form 10 of
this will be enzymatically rearranged to
replace the loss of rudp 5 and only two
will become glucose now for us to better
understand the Calvin cycle let us use
the interactive simulation that I
presented to you last video so here
we're going to choose Calvin cycle as
you can see there are three phases for
Calvin cycle for phase one we have the
carbon fixation phase two the reduction
phase and phase three we have the
Regeneration of rubp or
rp5 now let's proceed with phase one
which is the carbon fixation so this is
the Risco or the enzyme used in this
phase the rubp or rp5 as you can see
there are five carbons rubp or rp5 is
also known as carbon dioxide acceptor
during this phase carbon dioxide is
attached to rubp through the use of the
enzymes rubisco then it will become rudp
6 R udp6 will split into two molecules
of phosphoglycerate or three
phosphoglyceric acid again during carbon
fixation carbon dioxide is attached to
RPI by the enzymes Risco this forms two
molecules of three phosphor lerate for
each carbon dioxide added next we have
phase two the reduction phase here we're
going to use the phosphoglycerate the
nadph and ATP from the light dependent
reaction using the energy from ATP
phosphoglycerate are converted into
three carbon sugar while nadph will act
as an electron donor so from
phosphoglycerate it will become glycer
alhy 3 phosphate or G3 3p so we already
have one molecule of g3p so let's repeat
the
process as you can see after the
conversion of
ATP it will reduce to ADP and nadph will
become NP plus and Pi now ADP nadp plus
and Pi will be available again for the
light reaction again during the
reduction phase each molecule of three
phosphoglycerate is reduced to form g3p
and this requires energy from ATP and
electrons from nadph g3p is the final
product of the Calvin cycle one molecule
of g3p will leave the Calvin cycle and
be used to form organic compounds like
glucose or sugar now for the last phase
which is the Regeneration of rubp or
rp5 the other five g3p molecules are
used to regenerate rubp so that Calvin
cycle can continue the reactions that
regenerate rubp require energy to occur
this energy comes from ATP so here we're
going to drag the three ATP molecules to
the reaction site as you can see the
rubp or rudp 5 is readily available
again to continue the cycle the Calvin
cycle can now start over again with the
carbon fixation now to summarize
photosynthesis let us explain this
diagram
for light reaction this stage uses water
and changes light energy from the Sun
into chemical energy stored in ATP and
nadph this stage also releases oxygen as
a waste product for Calvin cycle this
stage combines carbon from carbon
dioxide in the air and uses the chemical
energy in ATP and nadph to make glucose
so that's it see you in our next lesson
and if you are new to my Channel please
don't forget to hit the Subscribe button
and hit the Bell notification so that
you will be notified for more videos
like this
Browse More Related Video
PHOTOSYNTHESIS: LIGHT_INDEPENDET REACTION or CALVIN CYCLE Tagalog
Photosynthesis - Light Dependent Reactions and the Calvin Cycle
Photosynthesis - Light-dependent Stage - Post 16 Biology (A Level, Pre-U, IB, AP Bio)
Photosynthesis Intro and Light-Dependent Reactions
BIOLOGI Kelas 12 - Metabolisme Part 3 (Anabolisme) | GIA Academy
Photosynthesis: Crash Course Biology #8
5.0 / 5 (0 votes)