Photosynthesis: Calvin CycleYouTube↗  IA↗(long shot)
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I think we're now ready to learn a little bit about the
Kita telah bersedia untuk belajar lebih banyak tentang
dark reactions.
tindak balas gelap.
But just to remember where we are in this whole scheme of
Imbas kembali apa yang berlaku semasa fotosintesis.
photosynthesis, photons came in and excited electrons in
Foton masuk dan merangsang elektron
chlorophyll in the light reactions.
dalam klorofil semasa tindak balas cahaya.
and as those photons went to lower and lower energy
Kadar tenaga foton semakin berkurang--
states-- we saw it over here in the last video-- as they
Kita telah lihatnya dalam video sebelum ini--
went to lower and lower energy states, and all of this was
Apabila kadar tenaganya semakin berkurang, semua ini
going on in the thylakoid membrane right over here.
memasuki membran tilakoid di sini.
You can imagine-- Let me do it in a different color.
Anda boleh bayangkan-- Biar saya gunakan warnya yang berbeza.
You can imagine it occurring right here.
Anda boleh bayangkannya berlaku di sini.
As they went into lower and lower energy states, two
Apabila kadar tenaganya semakin berkurang,
things happened.
2 perkara berlaku.
One, the release of energy was able to pump the hydrogens
Pertama, pembebasan tenaga membolehkan pengepaman hidrogen
across this membrane.
melintasi membran ini.
And then when you had a high concentration of hydrogens
Apabila terdapat tumpuan hidrogen yang banyak di sini,
here, those went back through the ATP synthase and drove
ia kembali melalui sintesis ATP dan
that motor to produce ATP.
mendorong motor itu untuk menghasilkan ATP .
And then the final electron acceptor, or hydrogen
Kemudian, penerima elektron yang terakhir, atau peneirma hidrogen,
acceptor, depending on how you want to view it.
bergantung kepada bagaimana anda melihatnya,
The whole hydrogen atom was NAD plus.
atom hidrogen ialah NAD+.
So the two byproducts, or the two byproducts that we're
Jadi, 2 produk sampingan, atau 2 produk sampingan
going to continue using in photosynthesis from our light
yang akan terus digunakan semasa fotosintesis dalam kitaran cahaya,
cycle, from our light reactions I guess.
daripada tindak balas cahaya,
I shouldn't call it the light cycle-- were-- I wrote it up
Saya tidak patut panggilnya kitaran cahaya-- Saya tulis di sini--
here-- ATP and NADPH.
ATP dan NADPH.
And then the byproduct was that we needed the electron to
Bagi produk sampingan, kita perlukan elektron untuk
replace that first excited electron.
menggantikan elektron yang telah dirangsang.
So we take it away from water.
Jadi, kita mengeluarkannya daripada air.
And so we also produce oxygen, which is a very valuable
Oksigen juga dihasilkan, ia ialah produk sampingan
byproduct of this reaction.
yang sangat bernilai daripada tindak balas ini.
But now that we have this ATP and this NADPH, we're ready to
Kini, terdapatnya ATP dan NADPH, kita telah bersedia untuk
proceed into the dark reactions.
teruskan dengan tindak balas gelap.
And I want to highlight again, even though it's called the
Saya mahu tegaskan lagi, walaupun ia dipanggil
dark reactions it doesn't mean that it happens at night.
tindak balas gelap, ini tidak bermakna ia berlaku pada waktu malam.
It actually happens at the same time as light reactions.
Sebenarnya, ia berlaku serentak dengan tindak balas cahaya.
It occurs while the sun is out.
Ia berlaku semasa terdapatnya cahaya matahari.
The reason why they call it the dark reactions is that
Tujuan ia dipanggail tindak balas gelap ialah
they're light independent.
ia adalah bebas cahaya.
They don't require photons.
Ia tidak memerlukan foton.
They only require ATP, NADPH, and carbon dioxide.
Ia hanya memerlukan ATP, NADPH dan karbon dioksida.
So let's understand what's going on here
Mari kita fahami apa yang berlaku di sini
a little bit better.
dengan lebih lanjut.
So let me go down to where I have some
Biar saya turun ke tempat yang ada
clean space down here.
ruang kosong di sini.
So we had our light reactions.
Jadi, terdapatnya tindak balas cahaya.
And they produced-- I just reviewed this-- produced some
Ia menghasilkan--
ATP and produced some and NADPH.
sedikit ATP dan NADPH.
And now we're going to take some carbon dioxide from the
Sedikit karbon dioksida akan diperoleh daripada
atmosphere.
udara.
And all of this will go into the-- I'll call it the light
Semua ini akan memasuki-- Saya akan panggilnya
independent reactions.
tindak balas bebas cahaya,
Because dark reactions is misleading.
ini kerana frasa "tindak balas gelap" adalah mengelirukan
So the light independent reactions, the actual
Jadi, tindak balas bebas cahaya, mekanisme yang sebenar
mechanism is called the Calvin Cycle.
dipanggil kitaran Calvin.
And that's what this video is really about.
Inilah topik video ini.
It goes into the Calvin Cycle and out pops-- whether you
Ia memasuki kitaran Calvin dan menghasilkan--
want to call it PGAL-- we talked about it in the first
Anda boleh panggilnya PGAL-- Kita bercakap tentangnya dalam
video-- or G3P.
video pertama-- atau G3P.
This is glyceraldehyde 3-phosphate.
Ini ialah gliseraldehid 3-fosfat.
This is phosphoglyceraldehyde They are the exact same
Ini ialah fosfogliseraldehid, kedua-duanya ialah molekul
molecule, just different names.
yang sama, cuma namanya yang berbeza.
And you can imagine it as a 3-carbon chain with a
Anda boleh bayangkannya sebagai rantaian 3-karbon bersama-sama
phosphate group.
kumpulan fosfat.
And then this can then be used to build other carbohydrates.
Ini boleh digunakan untuk membentuk karbohidrat yang lain.
You put two of these together you can get a glucose.
Dapatkan kedua-duanya dan terbentuknya glukosa.
You might remember in the first stage of glycolysis, or
Dalam peringkat pertama glukosa,
the first time we cut a glucose molecule we ended up
atau semasa kita memecahkan molekul glulosa, kita mendapat
with two phosphoglyceraldehyde molecules.
2 molekul fosfogliseraldehid.
Glucose has six carbons.
Glukosa ada 6 karbon.
This has three.
Yang ini ada 3.
Let's study the Calvin Cycle in just a
Mari kita kaji kitaran Calvin
little bit more detail.
dengan lebih mendalam.
So let's say exiting the light reactions, let's say we have--
Katakan, keluar daripada tindak balas cahaya dan kita ada--
well let's start off with six carbon dioxides.
Mari kita mulakan dengan 6 karbon dioksida.
So this is independent of the light reactions.
Ia adalah bebas daripada tindak balas cahaya.
And I'll show you why I'm using these numbers.
Saya akan tunjukkan kenapa saya gunakan nombor-nombor ini.
I don't have to use these exact numbers.
Saya tidak perlu gunakan nombor-nombor yang tepat ini.
So let's say I start off with six CO2s.
katakan, kita mulakan dengan 6 CO2.
And I could write a CO2 because we really care about
Saya gunakan CO2 kerana kita mengambil berat tentang
what's happening to the carbon.
apa yang berlaku kepada karbon.
We can just write it as a single carbon that has two
Kita gunakan 1 karbon yang ada 2 oksigen padanya,
oxygens on it, which I could draw.
saya akan lukisnya.
But I'm not going to draw them right now.
Tapi, saya tidak akan melukisnya sekarang
Because I want to really show you what
kerana saya mahu tunjukkan kepada anda
happens to the carbons.
apa yang berlaku kepada karbon.
Maybe I should draw this in this yellow.
Mungkin saya patut gunakan warna kuning
Just to show you only the carbons.
Saya hanya akan tunjukkan karbon saja.
I'm not showing you the oxygens on here.
Saya tidak akan tunjukkan oksigen di sini.
And what happens is the CO2, the six CO2s, essentially
Apa yang berlaku ialah, pada dasarnya, 6 CO2
react with-- and I'll talk a little bit about this reaction
bertindak balas dengan-- Saya akan bercakap tentang tindak balas ini
in a second-- they react with six molecules-- and this is
nanti-- Ia bertindak balas dengan 6 molekul--
going to look a little bit strange to you-- of this
Ia akan kelihatan pelik bagi anda--
molecule, you could call it RuBP.
Anda boleh panggil molekul ini sebagai RuBP.
That's short for ribulose biphosphate.
Ia singkatan bagi ribulosa dwifosfat.
Sometimes called ribulose-1 5-bisphosphate.
Kadangkala, ia dipanggil ribulosa-1 5-dwifosfat.
And the reason why it's called that is because it's a
Ia dipanggil begitu kerana ia ialah
5-carbon molecule.
molekul 5-karbon.
So, three, four five.
Jadi, 3, 4, 5.
And it has a phosphate on the 1 and 5 carbon.
Ia ada 1 fosfat dalam karbon pertama dan kelima.
So it's ribulose bisphosphate.
Jadi, ini ialah ribulosa dwifosfat,
Or sometimes, ribulosee-1-- let me write this-- that's the
atau kadangkala, ribulosa-1-- Biar saya tuliskannya-- Ini ialah
first carbon.
karbon pertama.
5-bisphosphate.
5-dwifosfat.
We have two phosphates.
Kita ada 2 fosfat.
So that's ribulose-1 5-bisphosphate.
Jadi, ini ialah ribulosa-1 5-dwifosfat.
Fancy name, but it's just a 5-carbon chain with 2
Nama yang istimewa, tapi ia hanyalah rantaian 5-karbon yang ada
phosphates on it.
2 fosfat padanya.
These two react together.
Kedua-duanya bertindak balas bersama-sama.
And this is a simplification.
Ini ialah kaedah mudah.
These two react together.
kedua-duanya bertindak balas bersama-sama.
There's a lot more going on here, but I want you to get
Banyak lagi yang berlaku di sini, tapi saya mahu anda dapat
the big picture.
gambaran keseluruhannya
to form, 12 molecules of PGAL, of phosphoglyceraldehyde or
untuk membentuk 12 molekul bagi PGAL,
glyceraldihyde 3-phosphate of PGAL, which you can view as
gliseraldehid 3-fosfat bagi PGAL,
a-- it has three carbons and then it has a phosphate group.
ia ada 3 karbon dan sekumpulan fosfat.
And just to make sure we're accounting for our carbons
Untuk memastikan kita ada jumlah karbon yang betul,
properly, let's think about what happens.
mari kita fikirkan apa yang berlaku.
We have 12 of these guys.
Kita ada 12 karbon.
You can think of it that we have-- 12 times
Bayangkan kita ada-- 12 x 3,
3-- we have 36 carbons.
kita ada 36 karbon.
Now did we start with 36 carbons?
Adakah kita mulakan dengan 36 karbon?
Well we have 6 times 5 carbons.
Kita ada 6 x 5 karbon,
That's 30.
iaitu 30.
Plus another 6 here.
Tambah satu lagi 6 di sini,
So, yes.
Jadi, betul,
We have 36 carbons.
kita ada 36 karbon.
They react with each other to form this PGAL.
Semuanya bertindak balas sesama sendiri untuk membentuk PGAL ini.
The bonds or the electrons in this molecule are in a higher
Ikatan atau elektron dalam molekul ini berada dalam
energy state than the electrons in this molecule.
keadaan tenaga yang lebih tinggi daripada elektron dalam molekul ini.
So we have to add energy in order for
Jadi, kita perlu menambah tenaga
this reaction to happen.
agar tindak balas ini boleh berlaku.
This won't happen spontaneously.
Ini tidak akan berlaku secara spontan.
And the energy for this reaction, if we use the
Tenaga untuk tindak balas ini, jika kita gunakan
numbers 6 and 6 here, the energy from this reaction is
nombor 6 dan 6 di sini, tenaga daripada tindak balas ini
going to come from 12 ATPs-- you could imagine 2 ATPs for
berpunca daripada 12 ATP-- Anda boleh bayangkan 2 ATP untuk
every carbon and every ribulose
setiap karbon, setiap ribulosa dwifosfat,
bisphosphate; and 12 NADPHs.
dan 12 NADPH.
I don't want to get you confused with-- it's very
Saya tidak mahu mengelirukan anda-- Ia adalah sama dengan NADH,
similar to NADH, but I don't want to get you confused with
tapi saya tidak mahu mengelirukan anda
what goes on in respiration.
dengan apa yang berlaku semasa respirasi.
And then these leave as 12 ADPs plus 12 phosphate groups.
Yang tinggal ialah 12 ADP + 12 kumpulan fosfat.
And then you're going to have plus 12 NADP pluses.
Kemudian, terdapatnya + 12 NADP+
And the reason why this is a source of energy is because
Ini ialah sumber tenaga kerana
the electrons in NADPH, or you could say the hydrogen with
elektron dalam NADPH, atau hidrogen bersama-sama
the electron in NADPH, is at a higher energy state.
elektron dalam NADPH, berada dalam keadaan tenaga tinggi.
So as it goes to lower energy state, it
Apabila ia berada dalam keadaan tenaga rendah,
helps drive a reaction.
ia membantu mendorong tindak balas.
And of course ATPs, when they lose their phosphate groups,
Dan apabila ATP kehilangan kumpulan fosfatnya,
those electrons are in a very high energy state, they enter
elektron akan berada dalam keadaan tenaga tinggi,
a lower energy state, help drive a reaction, help put
ia berubah menjadi keadaan tenaga rendah, membantu mendorong tindak balas,
energy into a reaction.
membantu memasukkan tenaga ke dalam tindak balas.
So then we have these 12 PGALs.
Kemudian, terdapatnya 12 PGAL ini.
Now the reason why it's called a Calvin Cycle-- as you can
Ia dipanggil kitaran Calvin kerana-- seperti yang anda boleh bayangkan--
imagine-- we studied the Kreb Cycle.
kita pernah pelajari kitaran Kreb,
Cycles start reusing things.
kitaran-kitaran ini mula menggunakan semula sesuatu.
The reason why it's called the Calvin Cycle is because we do
Ia dipanggil kitaran Calvin kerana
reuse, actually, most of these PGALs.
kebanyakan daripada PGAL ini digunakan semula.
So of the 12 PGALs, we're going to use 10 of them to--
Daripada 12 PGAL, 10 akan digunakan untuk--
let me actually do it this way.
Biar saya lakukannya begini.
So we're going to have 10 PGALs.
Kita ada 10 PGAL,
10 phosphoglyceraldehydes 10 PGALs we're going to use to
10 fosfogliseraldehid, 10 PGAL akan digunakan untuk
recreate the ribulose bisphosphate.
mewujudkan semula ribulosa dwifosfat.
And the counting works.
Kiraan kita betul.
Because we have ten 3-carbon molecules.
Sebab, kita ada 10 molekul 3-karbon,
That's 30 carbons.
iaitu 30 karbon.
Then we have six 5-carbon molecules.
Kemudian, kita ada 6 molekul 5-karbon,
30 carbons.
iaitu 30 karbon.
But this, once again, is going to take energy.
Tapi ini, sekali lagi,
This is going to take the energy from six ATPs.
ia akan mengambil tenaga daripada 6 ATP.
So you're going to have six ATPs essentially losing their
Jadi, 6 ATP akan kehilangan
phosphate group.
kumpulan fosfatnya.
The electrons enter lower energy
Elektron berada dalam keadaan tenaga rendah,
states, drive reactions.
mendorong tindak balas.
And you're going to have six ADPs plus six phosphate groups
6 ADP + 6 kumpulan fosfat
that get released.
yang dibebaskan.
And so you see it as a cycle.
Jadi, ia ialah sebuah kitaran.
But the question is, well gee I used all of these.
Tapi persoalannya, adakah kita akan gunakan semua ini?
What do I get out of it?
Apa yang kita dapat daripadanya?
Well I only used 10 out of the 12.
Saya hanya gunakan 10 daripada 12.
So I have 2 PGALs left.
Jadi, saya masih ada 2 PGAL.
And these can then be used-- and the reason why I used 6
Ini boleh digunakan-- Saya gunakan
and 6 is so that I get 12 here.
6 dan 6 agar saya dapat 12 di sini.
And I get 2 here.
Saya ada 2 di sini.
And the reason why I have 2 here is because 2 PGALs can be
Saya ada 2 di sini kerana 2 PGAL boleh
used to make a glucose.
digunakan untuk membentuk 1 glukosa,
Which is a 6-carbon molecule.
iaitu molekul 6-karbon.
It's formula, we've seen it before, is C6H12O6.
Kita pernah lihat formulanya, iaitu C6H12O6.
But it's important to remember that it doesn't have to just
Adalah penting untuk ingat bahawa ia tidak semestinya
be glucose.
ialah glukosa.
It can then go off and generate longer chained
Ia boleh berterusan dan membentuk rantaian karbohidrat yang lebih panjang
carbohydrates and starches, anything that
dan kaji, apa-apa saja yang
has a carbon backbone.
berdasarkan karbon.
So this is it.
Jadi, inilah dia.
This is the dark reaction.
Ini ialah tindak balas gelap.
We were able to take the byproducts of the light
Kita boleh ambil produk sampingan daripada tindak balas cahaya,
reactions, the ATP and the NADHs-- there's some more ATP
iaitu ATP dan NADH-- Ada sedikit lagi ATP
there-- and use it to fix carbon.
di situ-- dan gunakannya untuk mengikat karbon.
This is called carbon fixation.
Ini dipanggil pengikatan karbon.
When you take carbon in a gaseous form and you put it
Apabila karbon dalam bentuk gas dimasukkan
into a solid structure, that is called carbon fixation.
ke dalam struktur pejal, ia dipanggil pengikatan karbon.
So through this Calvin Cycle we were able to fix carbon and
Melalui kitaran Calvin, kita boleh mengikat karbon
the energy comes from these molecules generated from the
dan tenaga yang diperoleh daripada molekul
light reaction.
melalui tindak balas cahaya.
And of course, it's called a cycle because we generate
Ia dipanggil kitaran kerana PGAL ini dibentuk,
these PGALs, some of them can be used to actually produce
sesetengah daripadanya boleh digunakan untuk menghasilkan
glucose or other carbohydrates while most of them continue on
glukosa atau karbohidrat yang lain sementara kebanyakannya terus
to be recycled into ribulose bisphosphate, which once again
diguna semula sebagai ribulosa dwifosfat, yang sekali lagi
reacts with carbon dioxide.
bertindak balas dengan karbon dioksida.
And then you get this cycle happening over and over again.
Kitaran ini akan berterusan.
Now we said it doesn't happen in a vacuum.
Ia tidak berlaku secara berasingan.
Actually if you want to know the actual location where this
Jika anda mahu tahu lokasi yang tepat,
is occurring, this is all occurring in the stroma.
ia berlaku dalam stroma.
And the fluid inside the chloroplast but outside of
Bendalir dalam kloroplas, tapi di luar
your thylakoid.
tilakoid.
So in your stroma, this is where your light independent
Jadi, dalam stroma, di sinilah berlakunya
reactions are actually occurring.
tindak balas bebas cahaya.
And it's not just happening with the ADP and the NADPH.
Ia tidak hanya berlaku dengan ADP dan NADPH.
There's actually a fairly decent sized enzyme or protein
Sebenarnya, ada banyak enzim atau protein
that's facilitating it.
yang memudahkannya.
That's allowing the carbon dioxide to bond at certain
Ini membolehkan karbon dioksida untuk terikat pada suatu masa,
points and the ribulose bisphosphate and the ATP to
ribulosa dwifosfat dan ATP untuk
react at certain points, to essentially drive these two
bertindak balas pada suatu masa, pada dasarnya, mendorong kedua-duanya
guys to react together.
untuk bertindak balas bersama-sama.
And that enzyme, sometimes it's called RuBisCo, I'll tell
Enzim itu, kadangkala ia dipanggil RuBisCo.
you why it's called RuBisCo.
Saya akan terangkan kenapa ia dipanggil RuBisCo.
So this is RuBisCo.
Ini ialah RuBisCo.
So rub-- let me get the capitalization right--
Biar saya gunakan huruf besar.
ribulose bisphosphate rub-- bis-- co-- carboxylase.
ribulosa dwifosfat- karboksilase.
And this is what it looks like.
Ia kelihatan begini.
So it's a pretty big protein enzyme molecule.
Ia molekul enzim protein yang agak besar.
You can imagine that you have your ribulose bisphosphate
Bayangkan ribulosa dwifosfat
bonding at one point.
terikat pada suatu masa.
You have your carbon dioxide bonding at another point.
Karbon dioksida terikat pada suatu masa yang lain.
I don't know what points they are.
Saya tidak tahu bila.
ATP bonds at another point.
ATP terikat pada suatu masa yang lain.
It reacts.
Ia bertindak balas.
That makes this thing twist and turn in certain ways to
Ini menyebabkan benda ini berpusing dalam keadaan tertentu
make the ribulose bisphosphate react with the carbon dioxide.
dan mengakibatkan ribulosa dwifosfat bertindak balas dengan karbon dioksida.
NADPH might be reacting at other parts.
NADPH mungkin bertindak balas pada suatu masa yang lain.
And that's what facilitates this entire Calvin Cycle.
Inilah yang memudahkan keselururhan kitaran Calvin.
And you might-- I told you over here-- that this R U B P,
R U B P ini,
this is ribulose-1 5-bisphophate.
ini ialah ribulosa-1 5-dwifosfat.
This RuBisCo, this is short for ribulose-1 5-bisphophate
RuBisCo ialah singkatan bagi ribulosa-1 5-dwifosfat
carboxylase.
karboksilase.
I won't write it all out; you could look it up.
Saya tidak akan tulis semuanya; anda boleh carinya.
But it's just telling you, it's an enzyme that's used to
Ini untuk beritahu anda bahawa ia ialah enzim yang digunakan untuk
react carbon and ribulose-1 5-bisphophate.
bertindak balas dengan karbon dan ribulosa-1 5-dwifosfat.
But now we're done.
Selesai.
We're done with photosynthesis.
Fotosintesis telah selesai.
We were able to start off with photons and water to produce
Foton dan air akan menghasilkan
ATP and NADPH because we had those excited electrons, we
ATP dan NADPH kerana adanya elektron yang dirangsang,
had the whole chemiosmosis to drive the-- that allowed the
kemiosmosis akan mendorong--
ATP synthase to produce ATP.
sintesis ATP untuk menghasilkan ATP.
NADPH was the final electron acceptor.
NADPH ialah penerima elektron yang terakhir.
These are then used as the fuel in the Calvin Cycle, in
Semua ini akan digunakan sebagai bahan bakar dalam kitaran Calvin,
the dark reaction.
dalam tindak balas gelap.
Which is badly named, it should be called the light
Ia nama yang teruk, ia patut dipanggil
independent reaction.
tindak balas bebas cahaya
Because it actually does happen in the light.
kerana sebenarnya ia juga berlaku semasa ada cahaya matahari.
You take your fuel from the light reactions with some
Bahan bakar daripada tindak balas cahaya dan sedikit
carbon dioxide and you can fix it using your-- I like to call
karbon dioksida boleh diikat dengan menggunakan
it-- the RuBisCo enzyme in the Calvin Cycle.
enzim RuBisCo dalam kitaran Calvin.
And you end up with your phosphoglyceraldehyde which
Maka, terdapatnya fosfogliseraldehid
could also be called your glyceraldehyde 3-phosphate,
yang juga boleh dipanggil gliseraldehid 3-fosfat,
which can then be used to generate glucose, which we all
yang kemudiannya boleh digunakan untuk menghasilkan glukosa yang boleh
use to eat and fuel our bodies.
dimakan dan dijadikan tenaga bagi badan kita.
Or we learn in cellular respiration, that can then be
Atau, seperti yang kita belajar daripada respirasi sel,
converted into ATP when we need it.
boleh dijadikan ATP apabila kita perlukannya.
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