Light-Dependent Reaction - Key takeaways
- The light-dependent reaction is a series of reactions in photosynthesis that require light energy.
- The light-dependent reaction has three functions: to produce NADPH from NADP+ and H+ ions, to synthesise ATP from inorganic phosphate and ADP, and to break water into H+ ions, electrons, ...
- The overall equation for the light-dependent reaction is:
Full Answer
What happens during light independent stage of photosynthesis?
What are the stages of photosynthesis in order?
- Light Dependent. CO2 and H2O enter the leaf.
- Light Dependent. Light hits the pigment in the membrane of a thylakoid, splitting the H2O into O2.
- Light Dependent. The electrons move down to enzymes.
- Light Dependent. …
- Light independent. …
- Light independent. …
- calvin cycle.
What is the light independent stage of photosynthesis?
The light-independent stage of photosynthesis is sometimes referred to as the Calvin cycle; This stage produces complex organic molecules, including (but not limited to) carbohydrates, such as: Starch (for storage); Sucrose (for translocation around the plant); Cellulose (for making cell walls); The light-independent stage does not require energy from light and can therefore take place in ...
What are the light independent reactions in photosynthesis?
What three reactions occur during the light reactions in photosynthesis quizlet?
- Absorption of light energy.
- Conversion of light energy into chemical energy.
- hStorage of chemical energy in the form of sugars.
What is true about light dependent?
Which is true of light dependent reactions? Possible Answers: ATP is a product. GTP is a reactant. NADP+ is a product is a reactant. Correct answer: ATP is a product. Explanation: Light dependent reactions convert solar energy to chemical energy (in the form of ATP and NADPH). Sunlight and H2O are the reactant of the light dependent reaction.
What is light-dependent in photosynthesis?
The light-dependent reactions convert light energy into chemical energy. The goal of the light-dependent reactions of photosynthesis is to collect energy from the sun and break down water molecules to produce ATP and NADPH. These two energy-storing molecules are then used in the light-independent reactions.
How do light Dependant reactions work?
In the light-dependent reactions, which take place at the thylakoid membrane, chlorophyll absorbs energy from sunlight and then converts it into chemical energy with the use of water. The light-dependent reactions release oxygen as a byproduct as water is broken apart.
Is Calvin cycle light dependent?
The Calvin cycle refers to the light-independent reactions in photosynthesis that take place in three key steps. Although the Calvin Cycle is not directly dependent on light, it is indirectly dependent on light since the necessary energy carriers ( ATP and NADPH) are products of light-dependent reactions.
What is needed in light-dependent reactions?
The light dependent reaction uses water and light. Light provides the energy needed to break apart water molecule. This process will make oxygen and hydrogen ions. The hydrogen ions are used to make ATP.
Where do light dependent reactions occur?
The light-dependent reactions begin in a grouping of pigment molecules and proteins called a photosystem. Photosystems exist in the membranes of thylakoids. A pigment molecule in the photosystem absorbs one photon, a quantity or “packet” of light energy, at a time.
How does light energy enter the process of photosynthesis?
Light energy enters the process of photosynthesis when pigments absorb the light. In plants, pigment molecules absorb only visible light for photosynthesis. The visible light seen by humans as white light actually exists in a rainbow of colors.
What Is Light Energy?
Figure 2. The wavelength of a single wave is the distance between two consecutive points along the wave.
Which photosystem uses the electron to transport hydrogen ions into the interior of the thylakoid?
Figure 6. From photosystem II , the excited electron travels along a series of proteins. This electron transport system uses the energy from the electron to pump hydrogen ions into the interior of the thylakoid. A pigment molecule in photosystem I accepts the electron.
What energy do autotrophs use?
In the case of photosynthesis, light energy is transformed into chemical energy, which autotrophs use to build carbohydrate molecules. However, autotrophs only use a specific component of sunlight (Figure 1). Figure 1.
How can light be used to make food?
How can light be used to make food? It is easy to think of light as something that exists and allows living organisms, such as humans, to see, but light is a form of energy. Like all energy, light can travel, change form, and be harnessed to do work. In the case of photosynthesis, light energy is transformed into chemical energy, which autotrophs use to build carbohydrate molecules. However, autotrophs only use a specific component of sunlight (Figure 1).
Where does light energy come from in a reaction?
The energy culminates in a molecule of chlorophyll found in the reaction center. The energy “excites” one of its electrons enough to leave the molecule and be transferred to a nearby primary electron acceptor.
Where do light dependent reactions occur?
The light-dependent reactions begin in a grouping of pigment molecules and proteins called a photosystem. Photosystems exist in the membranes of thylakoids. A pigment molecule in the photosystem absorbs one photon, a quantity or “packet” of light energy, at a time.
How does light energy enter the process of photosynthesis?
Light energy enters the process of photosynthesis when pigments absorb the light. In plants, pigment molecules absorb only visible light for photosynthesis. The visible light seen by humans as white light actually exists in a rainbow of colors.
What Is Light Energy?
The sun emits an enormous amount of electromagnetic radiation (solar energy). Humans can see only a fraction of this energy, which is referred to as “visible light.” The manner in which solar energy travels can be described and measured as waves. Scientists can determine the amount of energy of a wave by measuring its wavelength, the distance between two consecutive, similar points in a series of waves, such as from crest to crest or trough to trough ( Figure 5.9 ).
How does light energy travel through chlorophyll?
A photon of light energy travels until it reaches a molecule of chlorophyll. The photon causes an electron in the chlorophyll to become “excited.” The energy given to the electron allows it to break free from an atom of the chlorophyll molecule. Chlorophyll is therefore said to “donate” an electron ( Figure 5.12 ).
How can pigments be identified?
Each type of pigment can be identified by the specific pattern of wavelengths it absorbs from visible light, which is its absorption spectrum. Many photosynthetic organisms have a mixture of pigments; between them, the organism can absorb energy from a wider range of visible-light wavelengths.
What energy do autotrophs use?
In the case of photosynthesis, light energy is transformed into chemical energy, which autotrophs use to build carbohydrate molecules. However, autotrophs only use a specific component of sunlight ( Figure 5.8 ).
Which photosystem accepts electrons?
Figure 5.13 From photosystem II , the electron travels along a series of proteins. This electron transport system uses the energy from the electron to pump hydrogen ions into the interior of the thylakoid. A pigment molecule in photosystem I accepts the electron.
What is the goal of light-dependent photosynthesis?
The goal of the light-dependent reactions of photosynthesis is to collect energy from the sun and break down water molecules to produce ATP and NADPH. These two energy-storing molecules are then used in the light-independent reactions. Within chloroplasts, chlorophyll is the pigment that absorbs sunlight. It is stored in the thylakoid membranes in ...
Where do light-dependent reactions take place?
The reactions that make up the process of photosynthesis can be divided into light-dependent reactions, which take place in the thylakoids, and light-independent reactions (also known as dark reactions or the Calvin cycle), which take place in the stroma. 1. Chloroplasts have a complex internal structure, and different reactions take place in ...
What is the name of the enzyme that breaks down carbon dioxide into two three-carbon molecules?
An enzyme in the stroma called ruBisCo combines a five-carbon molecule of RubP (ribulose biphosphate) with a molecule of carbon dioxide. This creates a six-carbon molecule that is broken down into two three-carbon molecules (3-phosphoglycerate). This part of the light-independent reactions is referred to as carbon fixation.
What is the goal of the light independent reactions?
The ultimate goal of the light-independent reactions (or Calvin cycle) is to assemble a molecule of glucose. This is the part of photosynthesis that requires the CO 2 the plant gets from the air. Essentially, the plant needs the carbon from the CO 2 to create the building blocks for glucose.
Which photosystem contains chlorophyll?
Meanwhile, the electron released from photosystem II arrives at photosystem I, which also contains chlorophyll. Energy from the sun excites the electron again, giving it enough energy to pass across the membrane and into the stroma, where it joins with a hydrogen ion and an NADP + to create the energy-carrying molecule NADPH. ...
What happens when photosystem 2 splits water?
This is a process humans haven’t been able to replicate exactly in a lab! Each water molecule breaks down into two hydrogen (H) atoms and one oxygen (O) atom.
What are the two main phases of photosynthesis?
Plant cell. Within the chloroplasts of a plant cell, photosynthesis occurs in two main phases: the light-dependent and light-independent reactions. Within plant cells, chloroplasts are specialized organelles that serve as the sites of photosynthesis. The reactions that make up the process of photosynthesis can be divided into light-dependent ...
Photoautotrophs
Plants are autotrophs, meaning that they are self-nourishing (Greek autos = self and trophe = nutrition). Specifically, plants are photoautotrophs because they use the energy from light to produce organic molecules with which they build their cells and store energy.
Light Reaction
Let’s start with light, because that’s where the plant gets the energy for photosynthesis. Here are some characteristics of light:
Light Independent Reaction
The Light-Independent Reaction (LIR) is the second part of photosynthesis. It takes place in the stroma of the chloroplast. It does not require light as the Light Reaction did; that’s why it is called Light-Independent.
Just to review again
In the light reaction, pigments in the thylakoid membrane capture energy from sunlight.
