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Engineering HSC and
IIT-JEE Mains and advanced videos. Hello
students today we are studying chapter
photo synthesis in that we're studying
topic Phosphorylation of
Photophosphorylation when I say
photophosphorylation it means formation
of ATP or you can say breakdown of ATP
ATP to ADP and then AMP now from 3 to 2
to 1 how does that happen we'll be
studying that today.
for the phosphorylation it is the
process of ATP synthesis ATP is made ADP
is adenosine triphosphate the main
energy won't kill whenever there is a
reaction inside a body ATP is needed as
a main energy source for example when
you're hungry and you need energy to do
work you eat food similarly when cells
have to do any function they need energy
molecules which are ATP and now when you
take ATP the full form of ATP is
adenosine triphosphate so example you
have one ATP and you have used it in
some energy so from that energy molecule
if you use one phosphate ATP becomes ADP
that is adenosine diphosphate again you
have used one phosphate then it becomes
a and B that is adenosine monophosphate
so this is how ATP is broken up now how
does that process happens of ATP
breaking down whenever light falls on
photosystems when I say photosystems
remember chlorophyll a will be
carotenoids xanthophyll present inside
the grandma yes there the photosystem or
LLC or light harvesting molecules which
have ability to absorb sunlight so when
light falls on photosystems the reaction
center absorb some amount of sunlight
example we are talking about pigment
system-1 so the reaction center of
pigment system one was 680 so when light
will fall on pigment system 1 the
reaction center will absorb energy which
is e 2 L into 680 now once it has
absorbed the energy it well into 680 in
the form of photons electrons get
excited and this electrons once they are
excited from the ground state they jump
to higher level state electrons they
move from the nucleus that is the nearby
position and grow to the primary etc
when I said primary acceptor it means
the first acceptor and then they pass to
the second acceptor thought acceptor is
so on and so forth now this works like a
tree until s they reach to the last
sectors and as electrons in the form of
photons move towards certain acceptor
the formation of ATP and nadph space in
PS 1 there are certain acceptors that
accept electrons which are inciting
process whereas in PS 2 there are
different set of electron acceptors
which help in the formation of ATP or
NADPH basic aim of this for the
phosphorylation is to generate maximum
amount of ATP and nadph which is
nicotinamide adenine phosphates so that
they can be used in the duct reaction of
photosynthesis you all know that that
reaction of photosynthesis uses ATP and
NADPH from the light reaction
for both phosphorylation photo bean
salad and phosphorylation means breakage
or breakdown basically the process of
photo phosphorylation is ATP synthesis
how ATP from adenosine triphosphate gets
converted into ADP that is adenosine
diphosphate and then into AMD that is
adenosine monophosphate this process
takes place in photo systems
the process of photophosphorylation
starts with male light or photon energy
from Sun falls on photosystems next the
reaction center absorbs particular
wavelength of sunlight example 680
nanometers if the reaction center has an
ability of 680 nanometers in the third
step electrons get excited that is if an
electron is present in its lower shell
on the other nucleus once it absorbs
energy the electron will jump to the
higher shell and this jump of electron
is to do the excited electron
in the next step electron move away from
the nucleus then it goes to the first
primary actor acceptor
it could be cytochrome B cytochrome F
whatever went depending upon the
photosystem then electrons are passed
through series of electron acceptors the
same electron acceptors which are
present in photosystem 1 and photosystem
at the end of this process that is at
the end of cycling for the
phosphorylation and noncyclic
photophosphorylation ATP is made which
could be used or probably wishes used in
the back reaction or the c3 cycle or
that Calvin cycle so students I hope you
are clear about the concept of
photophosphorylation thank you
