Bagaimanakah Tahapan Reaksi Terang?
Summary
TLDRThis educational video script delves into the crucial role of sunlight in photosynthesis, focusing on the light-dependent reactions. It explains the process of converting light energy into chemical energy via ATP and NADPH, occurring in the thylakoid membranes with the help of photosystems. The script introduces two types of photosystems (PS1 and PS2), their light absorption capabilities, and the role of electron carriers. It differentiates between non-cyclic and cyclic photophosphorylation, detailing how they produce ATP and, in the case of non-cyclic, oxygen and NADPH. The script challenges viewers to consider the impact of light conditions on these processes, promising further exploration in upcoming videos.
Takeaways
- 🌞 The sun's light plays a crucial role in life on Earth, particularly for producers.
- 🌿 Photosynthesis is the process by which plants use sunlight to convert carbon dioxide and water into glucose and oxygen.
- 🔬 Photosynthesis consists of two stages: the light-dependent reactions and the light-independent reactions (Calvin cycle).
- 🌱 The light-dependent reactions occur in the thylakoid membrane, where energy from sunlight is converted into chemical energy in the form of ATP and NADPH.
- 🔵 There are two types of photosystems involved in photosynthesis: Photosystem II (PSII), which absorbs light at 680 nanometers, and Photosystem I (PSI), which absorbs light at 700 nanometers.
- 💧 Photolysis of water occurs during the light-dependent reactions, producing hydrogen ions, electrons, and releasing oxygen as a byproduct.
- 🔁 Electrons are transferred through a series of carriers in the thylakoid membrane, including plastoquinone, cytochrome b6f complex, and plastocyanin.
- 🔋 The light-dependent reactions result in the production of ATP and NADPH, which are used in the Calvin cycle for the synthesis of glucose.
- ♻️ There are two types of photophosphorylation: non-cyclic and cyclic. Non-cyclic involves both PSII and PSI, while cyclic involves only PSI.
- 🌱 In non-cyclic photophosphorylation, electrons from PSII are passed to PSI, leading to the production of ATP and NADPH. In cyclic photophosphorylation, only ATP is produced without the production of NADPH or oxygen.
- 🌑 The light-dependent reactions require light, so if plants are placed in the dark and exposed to a flashlight, the reactions can still occur.
Q & A
What is the role of sunlight in the life on Earth?
-Sunlight plays a significant role in life on Earth, including being essential for producers, which are organisms that can convert light energy into chemical energy through photosynthesis.
What is photosynthesis and why is it important for plants?
-Photosynthesis is the process by which plants, algae, and some bacteria convert light energy into chemical energy in the form of glucose or other sugars. It's important for plants as it allows them to produce their own food and release oxygen as a byproduct.
What are the two stages of photosynthesis mentioned in the script?
-The two stages of photosynthesis mentioned are the light-dependent reactions and the light-independent reactions (also known as the Calvin cycle or dark reactions).
What happens during the light-dependent reactions of photosynthesis?
-During the light-dependent reactions, light energy is converted into chemical energy in the form of ATP and NADPH. This process requires light and takes place in the thylakoid membranes of the chloroplasts.
What are the two types of photosystems involved in the light-dependent reactions?
-The two types of photosystems involved are Photosystem II (PSII), known as p680, and Photosystem I (PSI), known as p700, which absorb light at different wavelengths.
What is the function of the electron carriers mentioned in the script?
-The electron carriers, including plastoquinone (PQ), cytochrome b6f complex, plastocyanin (PC), and ferredoxin (Fd), are responsible for transporting electrons during the light-dependent reactions of photosynthesis.
What is the significance of ATP synthase in the light-dependent reactions?
-ATP synthase plays a crucial role in the light-dependent reactions by catalyzing the synthesis of ATP from ADP and inorganic phosphate using the energy derived from the electron transport chain.
How does the process of photolysis of water occur during photosynthesis?
-Photolysis of water occurs when electrons are excited and leave PSII, leading to the splitting of water molecules into hydrogen ions, electrons, and oxygen gas, with oxygen being released into the atmosphere.
What is the difference between cyclic and non-cyclic photophosphorylation?
-Non-cyclic photophosphorylation involves both PSII and PSI and results in the production of ATP and NADPH. Cyclic photophosphorylation only involves PSI and results in the production of ATP without the production of NADPH or the release of oxygen.
What would happen if plants were placed in a dark room and exposed to a flashlight?
-If plants were placed in a dark room and exposed to a flashlight, the light-dependent reactions could still occur as long as the light is sufficient, but the light-independent reactions would not proceed without the products of the light-dependent reactions.
What is the challenge presented at the end of the script?
-The challenge is to consider whether the light-dependent reactions can still occur if plants are placed in a dark room and only exposed to the light from a flashlight.
Outlines
🌱 Understanding Photosynthesis: The Light Reaction
This paragraph introduces the concept of photosynthesis, specifically focusing on the light-dependent reactions. It explains the importance of sunlight for life on Earth and how plants utilize it. The video script mentions that viewers should watch a video about photosynthesis first for better understanding. The light reaction is described as the initial stage of photosynthesis, converting light energy into chemical energy in the form of ATP and NADPH. The location of this reaction in the thylakoid membrane is highlighted, along with the presence of two photosystems (Photosystem 2 and Photosystem 1), which absorb light at different wavelengths. The paragraph also discusses the role of electron carriers like plastoquinone, cytochrome, plastocyanin, and ferredoxin, as well as the enzymes ATP synthase and NADP+ reductase in the process. It concludes by explaining the two types of photophosphorylation: non-cyclic and cyclic, with the former involving both photosystems and the latter involving only Photosystem 1.
🌐 Deep Dive into the Light Reaction Pathways
The second paragraph delves deeper into the light reaction pathways of photosynthesis. It describes the process of photolysis of water, where water molecules are split into hydrogen ions and oxygen atoms, with the oxygen being released into the atmosphere. The hydrogen ions and electrons are used to generate ATP through a series of electron transfers involving plastoquinone, cytochrome, and plastocyanin. The paragraph also explains the non-cyclic electron transport chain, where electrons from Photosystem 2 are transferred to Photosystem 1, resulting in the production of ATP and NADPH. The cyclic photophosphorylation is also discussed, where only Photosystem 1 is involved, and electrons are recycled without the production of oxygen or NADPH. The paragraph ends with a challenge for viewers to consider whether the light reaction can occur in the absence of sunlight, setting the stage for the discussion of the dark reaction in a subsequent video.
Mindmap
Keywords
💡Photosynthesis
💡Light-dependent reactions
💡Thylakoid membranes
💡Photosystems
💡Electron transport chain
💡ATP (Adenosine Triphosphate)
💡NADPH
💡Cyclic photophosphorylation
💡Non-cyclic photophosphorylation
💡Water photolysis
💡Stoma
Highlights
The role of sunlight is crucial for life on Earth, particularly for producers.
Before watching the video, it's recommended to watch a video about photosynthesis for better understanding.
Photosynthesis consists of two stages: light-dependent reactions and light-independent reactions (Calvin cycle).
The light-dependent reactions are the initial phase of photosynthesis that convert light energy into chemical energy in the form of ATP and NADPH.
Light-dependent reactions require sunlight and take place in the thylakoid membranes.
The thylakoid membrane contains two types of photosystems: Photosystem II (PSII) and Photosystem I (PSI).
Photosystem II absorbs light at a wavelength of 680 nanometers, while Photosystem I absorbs light at 700 nanometers.
Electron carriers such as plastoquinone, cytochrome b6f complex, plastocyanin, and ferredoxin are involved in the electron transfer process.
ATP synthase is responsible for the production of ATP during the light-dependent reactions.
Light-dependent reactions involve two types of photophosphorylation: non-cyclic and cyclic.
Non-cyclic photophosphorylation involves both PSII and PSI, while cyclic photophosphorylation only involves PSI.
In non-cyclic photophosphorylation, oxygen is released as a byproduct of water photolysis.
Cyclic photophosphorylation does not involve water photolysis, thus no oxygen is produced.
The challenge posed is whether light-dependent reactions can occur in the dark with the use of a flashlight.
The video concludes with an invitation to explore more about the Calvin cycle in the next video.
The video encourages viewers to visit the school's website and download the app for exclusive discounts and offers.
The video also promotes subscribing to the school's channel and following their social media for more educational content.
Transcripts
wu
halo halo kawan murid kita semua udah
tahu ya kalau cahaya matahari memiliki
peranan yang besar bagi kehidupan di
Bumi salah satunya adalah bagi produsen
yang mana kedudukan produsen di bumi
dipegang oleh Tuhan
Hai tapi Pernah gak sih kita berpikir
bagaimana cahaya matahari dapat
digunakan oleh tumbuhan Yuk kita
pelajari sama-sama sebelum menonton
video ini kamu bisa menonton video
tentang fotosintesis terlebih dahulu ya
supaya kamu lebih paham saat menonton
video ini di video sebelumnya kita udah
singgung kalau fotosintesis terdiri dari
dua tahapan yaitu reaksi terang dan
reaksi gelap pada video kali ini kita
hanya akan membahas tentang reaksi
terang yang meliputi pengertian lokasi
atau tempat terjadinya dan prosesnya
reaksi truk merupakan tahapan awal
fotosintesis yang mengubah energi cahaya
menjadi energi kimia dalam bentuk ATP
dan nadph jadi yang harus diingat adalah
reaksi terang ini merupakan tahapan
reaksi fotosintesis
yang memerlukan cahaya matahari Lalu
gimana sih tempat terjadinya reaksi
terang di video sebelumnya hidroponik
ini terang ini terjadinya di membran
tilakoid jika diperbesar penampakan
membran tilakoid akan terlihat seperti
gambar berikut pada membran tilakoid
terdapat fotosistem 2 merupakan
seperangkat alat untuk menangkap Proton
atau cahaya matahari ada dua jenis
fotosistem yaitu fotosistem 1 atau
dikenal sebagai p700 disebut dengan p700
karena mampu menyerap cahaya dengan
panjang gelombang 700 nanometer dan
terdapat juga fotosistem 2 atau yang
dikenal sebagai p680 disebut dengan p680
karena mampu menyerap cahaya dengan
panjang gelombang 680 nanometer
Hai pada membran tilakoid ini juga
terdapat pembawa elektron yang terdiri
dari plastokuinon atau PQ kompleks
sitokrom atau kyb plastosianin atau pc
dan feredoksin atau FB keempat komponen
ini bertugas untuk membawa elektron
Selain itu terdapat juga eh ADP
reduktase yang akan membantu
menghasilkan nadph dan ATP sintase yang
akan menghasilkan ATP pada reaksi terang
fotosintesis terdiri dari dua reaksi
yaitu fotofosforilasi nonsiklik dan
fotofosforilasi siklik fotofosforilasi
nonsiklik melibatkan dua fotosistem 2
dan fotosistem 1 sedangkan
fotofosforilasi siklik hanya melibatkan
fotosistem 1 saja ya
kita mulai dengan fotofosforilasi
nonsiklik energi foton yang berasal dari
cahaya matahari akan diserap fotosistem
2 atau p680 selanjutnya energi foton
dari cahaya akan memicu eksitasi
elektron atau terlepasnya elektron dari
p680 yang akan ditangkap oleh akseptor
primate p680 akan mengalami kekosongan
elektron yang menyebabkan fotolisis air
yaitu gua 2o akan diurai menjadi dua ion
hidrogen dan 1/2 atom oksigen 2 elektron
nah Dua elektron ini akan menuju p680
untuk mengisi kekosongan elektron agar
tetap stabil oksigen akan dilepaskan ke
udara sedangkan hidrogen untuk sementara
waktu tinggal di ruang tilakoid
Hai selanjutnya elektron akan
meninggalkan p680 elektron ini akan
dibawa oleh plastokuinon sitokrom dan
plastosianin pada saat pos coquinone
mengirimkan elektron ke sitokrom 4 ion
hidrogen yang ada di stroma akan masuk
melintasi membran tilakoid menuju ruang
tilakoid yang nantinya akan bergabung
dengan ion hasil fotosintesis menuju ATP
synthase pada saat melewati ATP synthase
terjadi fotofosforilasi terhadap kdp dan
W sehingga dihasilkan ATP detik
fotosistem 1 terkena cahaya elektron
yang ada di p700 ini juga akan
tereksitasi menuju akseptor primer
sehingga keadaan fotosistem 1 tidak
stabil untuk menstabilkannya maka harus
diisi kembali oleh
crown yang berasal dari p680 maka
elektron yang ada di playstore cyanine
akan menuju p700 selanjutnya elektron
dari p700 akan menuju feredoksin untuk
ditransfer ke ennard reduktase elektron
ini bersama dengan nadp + dan ion H +
akan menjalani suatu reaksi sehingga
membentuk nadph dengan demikian jalur
nonsiklik Ini menghasilkan ATP dan nadph
keduanya akan digunakan dalam tahapan
reaksi gelap selanjutnya kita bahas
tentang fotofosforilasi siklik
fotosistem yang berperan pada jalur
siklik ini hanyalah fotosistem 1 atau
p700 reaksi pada fotofosforilasi siklik
ini diawali ketika energi foton dari
cahaya matahari
ini ditangkap oleh p700 dan
mengakibatkan eksitasi elektron elektron
yang tereksitasi kemudian akan ditangkap
oleh akseptor primer nantinya akan
dikembalikan lagi ke v700 melalui
transfer elektron feredoksin sitokrom
dan plastosianin pada saat transfer
elektron terbentuk ATP yang berasal dari
ADB karena elektron kembali pada p700a
tidak terjadi fotolisis air sehingga
pada fotofosforilasi siklik ini tidak
dihasilkan oksigen dan nadph seperti
pada fotofosforilasi nonsiklik sistem
ini bersifat siklis atau berputar
artinya elektron yang dikeluarkan
fotosistem 1 akan balik lagi ke
fotosistem 1 kasur dari fotofosforilasi
siklik adalah energi yang berupa ATP
Hai demikianlah materi tentang tahapan
reaksi terang fotosintesis jadi kamu
sudah paham kan materi tentang reaksi
terang ini selanjutnya saya punya
tantangan nih buat kamu reaksi Terangkan
memerlukan cahaya matahari lalu jika
tumbuhan kita letakkan di ruang gelap
dan kita beri cahaya senter Apakah
reaksi terang bisa tetap terjadi di
video selanjutnya kita akan melanjutkan
pembahasan tentang reaksi gelap sampai
jumpa
Hai Terima kasih sudah menonton video
kolaborasi eksakta educator dan
sekolahmu Ayo kunjungi website sekolahmu
dan download aplikasinya khusus bagi
kamu yang udah nonton video ini ada
beasiswa program belajar dari sekolahmu
gunakan kode kamu banget untuk
mendapatkan diskon 50% jangan lupa juga
subscribe channel sekolahmu Indonesia
dan follow akun media sosial lainnya ya
ya
Посмотреть больше похожих видео
PHOTOSYNTHESIS: LIGHT DEPENDENT REACTION || CYCLIC & NON-CYCLIC REACTION | Grade 9 Science _ BIOLOGY
Photosynthesis - Light-dependent Stage - Post 16 Biology (A Level, Pre-U, IB, AP Bio)
Reaksi Terang Fotosintesis
Photosynthesis Intro and Light-Dependent Reactions
BIOKIMIA FOTOSINTESIS REAKSI TERANG
Photosynthesis - Light Dependent Reactions and the Calvin Cycle
5.0 / 5 (0 votes)