Name: photosystem i and nadph formation
Uploaded: 2019-03-11T09:21:12.000Z
Duration: 1 min 27 s
Channel: JoVE

K12 Standards

Louisiana Student Standards for Science

High School

Environmental Science

Earth’s Systems

HS-ESS2-6

Photosystem I

De la même façon que dans le photosystème II,dans le phostosystème I, les photons sont absorbéspar les molécules pigmentaires dans l'antenne collectricepour relayer l'énergie vers le centre réactionnelet à la suite de l'oxydation,un électron à haute énergie passeà l'accepteur primaire. 
Mais cette fois,les électrons manquants de la paire de moléculesde chlorophylle Asont remplacés par ceux voyageant du photosystème IIpar la chaîne de transport d'électrons. 
De la molécule porteuse plastoquinonevers le complexe cytochromevers une autre protéine, la plastocyanine. 
L'énergie libérée par cette réactionest utilisée pour pomper des protons dansl'espace du thylakoïdepar le complexe cytochromecréant un gradient de protons qui génère de l'ATPpar la chimiosmose. 
Une fois que l'électron passe par le centre réactionnel,il entre dans la seconde chaîne de transport d'électrons,d'abord par le complexe de protéine ferrédoxine. 
De là, ce simple électron est acceptépar le NADP+ réductase qui,en plus d'un autre électron et proton,formera le produit énergétique NADPH.

<ol>
	<li>Cardona, T., Shao, S., Nixon, P.J. Améliorer la photosynthèse chez les plantes : les réactions à la lumière. Essais en biochimie. 62 (1), 85 à 94 (2018).</li>
</ol>

photosystème i

<h4>Aperçu</h4>
 
 Comme le photosystème II (PS II), le photosystème I (PS I) capte les photons et les transporte par le biais de molécules de chlorophylle dans un centre réactionnel. Dans le PS I, les photons redynamisent les électrons qui sont entrés dans le PS I à partir du PS II. Depuis le centre réactionnel, l’électron de haute énergie est transmise à une chaîne de transport d’électrons et il se joint finalement à un électron supplémentaire et à un proton pour réduire le NADP+ en NADPH. Ainsi, de la même façon que le PS II capte de l’énergie pour générer de l’ATP, le PS I capte de l’énergie pour créer du NADPH.
 
 <h4>Photosystème I</h4>
 
 Les pigments du complexe de récupération de la lumière dans le photosystème I absorbent les photons et transmettent l’énergie au centre réactionnel (P700). Après l’oxydation, un électron de haute énergie passe de la paire spécialisée de chlorophylle a à l’accepteur d’électrons primaire. Cette fois, cependant, les électrons manquants de la paire de chlorophylle a sont remplacés par les électrons se propageant à partir du photosystème II (au lieu du fractionnement de l’eau comme dans le PS II). Sur le chemin du PS II au PS I, les électrons passent par la chaîne de transport d’électrons, comprenant la molécule porteuse plastoquinone, le complexe double cytochrome protéine et la plastocyanine.
 
 Une fois que l’électron a été excité dans le centre réactionnel du PS I, il entre dans une seconde chaîne de transport d’électrons — le complexe protéique ferrédoxine. L’électron unique se joint ensuite à un autre électron et à un proton (H+) qui sont tous acceptés par la NADP+ réductase pour former le produit NADPH. Ainsi, le PS II capte l’énergie pour créer un gradient de protons qui est finalement utilisé pour fabriquer de l’ATP, et l’énergie captée dans le PS I est utilisée pour produire du NADPH.

Photosystème I

Bien que structurellement similaire au photosystème II (PSII), le photosystème I (PSI) a un fournisseur d’électrons et un accepteur d’électrons différents.
Ces deux ...

Education

Enseignement

JoVE Core

Biology

Biologie

Cellular Processes

Processus cellulaires

Photosynthesis

Photosynthèse

KEY TERMS AND CONCEPTS

TERMES ET CONCEPTS CLÉS

photosystem i and nadph formation

Photosystem I helps convert light energy into NADPH during photosynthesis. It works with photosystem II in the thylakoid membrane of the chloroplast, but it uses a different electron supplier and a different electron acceptor.

Electrons excited in photosystem II move to photosystem I through an electron transport chain. That chain includes plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As the electrons travel between the two photosystems, they lose energy and must be re-energized by photosystem I.

To do this, the pigments in the photosystem I antenna complex absorb another photon. The energy is passed to the reaction center called P700. P700 then sends a high-energy electron to NADP+ and forms NADPH.

Photosystem II uses light energy to build a proton gradient and make ATP. Photosystem I captures light energy to reduce NADP+ into NADPH. After ATP and NADPH are made, the cell has the energy it needs to build carbohydrate molecules for long-term storage in the stroma of the chloroplast.

Photosystem I and NADPH Formation

what is photosynthesis?

Photosynthesis in Chloroplasts and Leaves

Photosynthesis happens in plants and in some bacteria. It is the process that captures carbon dioxide and solar energy to make glucose. Glucose stores chemical energy as carbohydrates. The overall biochemical equation is 6 CO2 + 6 H2O + light energy → C6H12O6 + 6 O2. Photosynthesis also releases oxygen into the atmosphere and helps maintain Earth’s atmospheric oxygen content. Photosynthetic reactions take place in chloroplasts, which are specialized membrane-enclosed parts of the plant cell.

light as energy

How Plant Pigments Capture Light

Photosynthesis uses light energy from the sun, which is a form of electromagnetic radiation. The full range of possible wavelengths is called the electromagnetic spectrum. Light is made of photons, which are small packets of energy. Photons act like waves and are described by frequency, wavelength, and amplitude. Waves with higher frequencies carry more energy and have shorter wavelengths. Waves with lower frequencies carry less energy and have longer wavelengths. For most organisms,...

anatomy of chloroplasts

Chloroplasts and Photosynthesis in Plant Cells

Chloroplasts are the organelles where photosynthesis takes place in green algae and plants. They are also found in green stems and unripe fruit. In plants, mesophyll cells in the leaf contain the highest density of chloroplasts. Each chloroplast has a double membrane. The outer membrane faces the plant cell cytoplasm on one side and the chloroplast intermembrane space on the other. The inner membrane separates that narrow space from the stroma, which is the watery interior of the chloroplast.

photosystem ii

Photosystem II and Water Splitting

Photosystem II is a multi-protein complex that captures light energy and begins the flow of electrons in photosynthesis. It uses bound pigments to harvest photons and send that energy to its reaction center. From there, the energy continues through the electron transport chain and on to photosystem I. The pigments in photosystem II include chlorophyll a, chlorophyll b, and carotenoids. They are arranged in two parts of the photosystem: the antenna complex and the reaction center. The antenna...

photosystem i

Photosystem I helps convert light energy into NADPH during photosynthesis. It works with photosystem II in the thylakoid membrane of the chloroplast, but it uses a different electron supplier and a different electron acceptor. Electrons excited in photosystem II move to photosystem I through an electron transport chain. That chain includes plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As the electrons travel between the two photosystems, they lose energy and must be...

the calvin cycle

Carbon Fixation in Photosynthesis

Photosynthesis uses light energy to turn carbon dioxide into carbohydrates. It also releases oxygen as a by-product. These products help support most food webs and make aerobic life possible. Photosynthesis has two main stages, and they happen in different parts of the chloroplast. The light-dependent reactions take place in the thylakoid membranes. Chlorophyll absorbs light energy there and helps split water molecules. This releases O2 and makes ATP and NADPH. The light-independent reactions...

c4 pathway and cam

Plant Carbon Fixation in Hot Climates

Plant carbon fixation in hot climates can follow the C4 pathway or the CAM pathway. These alternative pathways help some plants reduce energy loss from photorespiration. Photorespiration happens when oxygen levels are high and rubisco, the enzyme in the Calvin cycle, binds O2 instead of CO2. When that happens, photosynthesis slows and energy is used up. The C4 pathway is used by plants such as corn and sugarcane. In mesophyll cells, CO2 first joins with PEP, or phosphoenolpyruvate, through the...

key terms and concepts

Learn how photosystem I re-energizes electrons, reduces NADP+ to NADPH, and works with photosystem II to help build sugars in chloroplasts.

Photosystem I and NADPH Formation | JoVE K12

JoVE Core series brings biology to life through over 300 concise and easy-to-understand animated video lessons that explain key concepts in biology, plus more than 150 scientist-in-action videos that show actual research experiments conducted in today’s laboratories.

biology

La collection JoVE Core Biologie donne vie à la biologie à travers plus de 300 leçons vidéos animées concises et faciles à comprendre qui expliquent les concept clés de la biologie, mais aussi plus de 150 vidéos de scientifiques à l'action effectuant des expériences de recherche dans des laboratoires modernes.

Virginia  Standards of Learning

HIgh School

Life Science

LS.4

LS.4.a

Next Generation Science Standards

from-molecules-to-organisms-structures-and-processes

From Molecules to Organisms: Structures and Processes

HS-LS1-5

Texas Essential Knowledge and Skills

BIO.11

BIO.11.A

south-carolina-college-and-career-ready-science-standards

South Carolina College and Career Ready Science Standards

ecosystems-interactions-energy-and-dynamics

Ecosystems: Interactions, Energy, and Dynamics

B-LS2-5.

new-york-state-science-learning-standards

New York State Science Learning Standards

matter-and-energy-in-organisms-and-ecosystems

Matter and Energy in Organisms and Ecosystems

HS-LS1-5.

Georgia Standards of Excellence

9-12

SB1.e

myJoVE Corporation

determining-spatial-orientation-rock-layers-with-brunton

Determining Spatial Orientation of Rock Layers with the Brunton Compass

Source: Laboratory of Alan Lester - University of Colorado Boulder
Most rock units exhibit some form of planar surfaces or linear features. Examples ...

using-topographic-maps-to-generate-topographic-profiles

Using Topographic Maps to Generate Topographic Profiles

Source: Laboratory of Alan Lester - University of Colorado Boulder
Topographic maps are &#34;plan-view&#34; representations of Earth&#39;s ...

exploring-effects-atmospheric-forcings-on-evaporation-experimental

Exploring the Effects of Atmospheric Forcings on Evaporation: Experimental Integration of the Atmospheric Boundary Layer and Shallow Subsurface

Evaporation is directly influenced by the interactions between the atmosphere, land surface and soil subsurface. This work aims to experimentally study ...

Earth’s systems, being dynamic and interacting, include feedback effects that can increase or decrease the original changes.

HS-ESS2-2

What is Weather?

Overview

Weather refers to the current state of atmospheric conditions at a specific time and place. Weather is temporary and is influenced by the ...

What is Climate?

Climate refers to the prevailing weather conditions in a specific area over an extended period. As the saying goes, &#8220;Climate is what you expect. ...

Global Climate Change

Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global ...

The geological record shows that changes to global and regional climate can be caused by interactions among changes in the sun’s energy output or Earth’s orbit, tectonic events, hydrosphere circulation, volcanic activity, glaciers, vegetation, and human activities. These changes can occur on a variety of time scales from sudden (e.g., volcanic ash clouds) to intermediate (ice ages) to very long-term tectonic cycles.

HS-ESS2-4

Making a Geologic Cross Section

Source: Laboratory of Alan Lester - University of Colorado Boulder
Geologic maps were first made and utilized in Europe, in the mid-to-late 18th century. ...

physical-properties-of-minerals-i-crystals-and-cleavage

Physical Properties Of Minerals I: Crystals and Cleavage

Source: Laboratory of Alan Lester - University of Colorado Boulder
The physical properties of minerals comprise various measurable and discernible ...

physical-properties-of-minerals-ii-polymineralic-analysis

Physical Properties Of Minerals II: Polymineralic Analysis

Source: Laboratory of Alan Lester - University of Colorado Boulder
The physical properties of minerals include various measurable and discernible ...

Igneous Volcanic Rock

Source: Laboratory of Alan Lester - University of Colorado Boulder
Igneous rocks are the products of cooling and crystallization of magma. Volcanic rocks ...

Igneous Intrusive Rock

Source: Laboratory of Alan Lester - University of Colorado Boulder
Igneous rocks are products of the cooling and crystallization of high temperature ...

The abundance of liquid water on Earth’s surface and its unique combination of physical and chemical properties are central to the planet’s dynamics. These properties include water’s exceptional capacity to absorb, store, and release large amounts of energy, transmit sunlight, expand upon freezing, dissolve and transport materials, and lower the viscosities and melting points of rocks.

HS-ESS2-5

The foundation for Earth’s global climate systems is the electromagnetic radiation from the sun, as well as its reflection, absorption, storage, and redistribution among the atmosphere, hydrosphere, and land systems, and this energy’s re-radiation into space.

What is Photosynthesis?

Photosynthesis is a multipart, biochemical process that occurs in plants as well as in some bacteria. It captures carbon dioxide and solar energy to ...

Light as Energy

The energy required to carry out photosynthesis is light&#8212; typically electromagnetic radiation from the sun. The range of all possible wavelengths is ...

Anatomy of Chloroplasts

Green algae and plants, including green stems and unripe fruit, harbor chloroplasts&mdash;the vital organelles where photosynthesis takes place. In ...

Photosystem II

The multi-protein complex photosystem II (PS II) harvests photons and transfers their energy through its bound pigments to its reaction center, and ...

Although structurally similar to photosystem II (PSII), photosystem I (PSI) is has a different electron supplier and electron acceptor.
Both these ...

The Calvin Cycle

Overview

Oxygenic photosynthesis converts approximately 200 billion tons of carbon dioxide (CO2) annually to organic compounds and produces approximately ...

C4 Pathway and CAM

Most plants use the C3 pathway for carbon fixation. However, some plants, such as sugar cane, corn, and cacti that grow in hot conditions, use alternative ...

Measuring Tropospheric Ozone

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
Ozone is a form of elemental oxygen (O3), a molecule of three oxygen atoms ...

determination-of-nox-in-automobile-exhaust-using-uv-vis-spectroscopy

Determination Of NOx in Automobile Exhaust Using UV-VIS Spectroscopy

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
In the troposphere, ozone is naturally formed when sunlight splits nitrogen ...

carbon-and-nitrogen-analysis-of-environmental-samples

Carbon and Nitrogen Analysis of Environmental Samples

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
Elemental Analysis is a method used to determine elemental composition of a ...

Gradual atmospheric changes were due to plants and other organisms that captured carbon dioxide and released oxygen.

What are Biogeochemical Cycles?

The most common elements in organic molecules, carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorus, are only available in the ecosystem in limited ...

Cyclical changes in the shape of Earth’s orbit around the sun, together with changes in the tilt of the planet’s axis of rotation, both occurring over hundreds of thousands of years, have altered the intensity and distribution of sunlight falling on Earth. These phenomena cause a cycle of ice ages and other gradual climate changes.

Photosystem I and NADPH Formation

Description

Transcript

Tags

More videos by Standards