biology exam 3
Describe what goes into the Calvin cycle, and what comes out of the Calvin cycle.
In the Calvin cycle, carbon atoms from CO2start text, C, O, end text, start subscript, 2, end subscript are fixed (incorporated into organic molecules) and used to build three-carbon sugars. This process is fueled by, and dependent on, ATP and NADPH from the light reactions. The reactions of the Calvin cycle add carbon (from carbon dioxide in the atmosphere) to a simple five-carbon molecule called RuBP. ... The final product of the Calvin cycle is glucose.
Explain how the light reactions are interconnected to the Calvin cycle
In the light-dependent reactions, energy absorbed by sunlight is stored by two types of energy-carrier molecules: ATP and NADPH. ... When these molecules release energy into the Calvin cycle, they each lose atoms to become the lower-energy molecules ADP and NADP+.
What is Water's role in the light reaction of photosynthesis?
Light reactions -- light energy in the presence of chlorophyll -- splits water. Splitting water into oxygen gas, hydrogen ions and electrons produces the energy for subsequent electron and proton transport and provides the energy to produce the sugars the plant needs. These subsequent reactions form the Calvin cycle.
What are the basic stages of the Calvin cycle?
The Calvin cycle has four main steps: carbon fixation, reduction phase, carbohydrate formation, and regeneration phase. Energy to fuel chemical reactions in this sugar-generating process is provided by ATP and NADPH, chemical compounds which contain the energy plants have captured from sunlight.
Describe how ATP and NADPH are produced during the light-capturing reactions of photosynthesis.
The Light Reactions of Photosynthesis. Light is absorbed and the energy is used to drive electrons from water to generate NADPH and to drive protons across a membrane. These protons return through ATP synthase to make ATP.
Describe the overall purpose of photosynthesis
The main purpose of photosynthesis is to convert radiant energy from the sun into chemical energy that can be used for food. Cellular respiration is the process that occurs in the mitochondria of organisms (animals and plants) to break down sugar in the presence of oxygen to release energy in the form of ATP.
What is the role of photosystem 1 and 2?
The primary function of the photosystem I is in NADPH synthesis, where it receives the electrons from PS II. The primary function of the photosystem II is in the hydrolysis of water and ATP synthesis. The PSI is made up of two subunits which are psaA and psaB.
How is ATP synthesis coupled with the reactions of photosystem 2?
This is accomplished by the use of two different photosystems in the light reactions of photosynthesis, one to generate ATP and the other to generate NADPH. ... Electron transport through photosystem II is thus coupled to establishment of a proton gradient, which drives the chemiosmotic synthesis of ATP.
How is energy transmitted from light to the reaction center complex?
A photon strikes the antenna pigments of photosystem II to initiate photosynthesis. The energy travels to the reaction center that contains chlorophyll a to the electron transport chain, which pumps hydrogen ions into the thylakoid interior. This action builds up a high concentration of ions.
How is ATP related to the reactions of cellular respiration?
During the process of glycolysis in cellular respiration, glucose is oxidized to carbon dioxide and water. Energy released during the reaction is captured by the energy-carrying molecule ATP (adenosine triphosphate).Oct
Compare and contrast cellular respiration and photosynthesis.
While photosynthesis requires carbon dioxide and releases oxygen, cellular respiration requires oxygen and releases carbon dioxide. It is the released oxygen that is used by us and most other organisms for cellular respiration. We breathe in that oxygen, which is carried through our blood to all our cells.
Students will be able to differentiate between anaerobic respiration and fermentation.
Even though fermentation happens without oxygen, it isn't the same as anaerobic respiration. ... However, instead of ending with glycolysis, as fermentation does, anaerobic respiration creates pyruvate and then continues on the same path as aerobic respiration.
What happens when light hits the pigment in photosystem II?
In the first part of photosynthesis, the light-dependent reaction, pigment molecules absorb energy from sunlight. ... A photon strikes photosystem II to initiate photosynthesis. Energy travels through the electron transport chain, which pumps hydrogen ions into the thylakoid space. This forms an electrochemical gradient.
Explain what happens to g3p produced by the Calvin cycle.
One of the three-carbon molecules of G3P leaves the cycle to become a part of a carbohydrate molecule. The remaining G3P molecules stay in the cycle to be formed back into RuBP, which is ready to react with more CO2. Photosynthesis forms a balanced energy cycle with the process of cellular respiration.
Describe the structure of a chloroplast, and relate this to different parts of photosynthesis.
Photosynthetic cells contain special pigments that absorb light energy. ... In plants, photosynthesis takes place in chloroplasts, which contain the chlorophyll. Chloroplasts are surrounded by a double membrane and contain a third inner membrane, called the thylakoid membrane, that forms long folds within the organelle. The chloroplast has an inner and outer membrane with an empty intermediate space in between. Inside the chloroplast are stacks of thylakoids, called grana, as well as stroma, the dense fluid inside of the chloroplast. These thylakoids contain the chlorophyll that is necessary for the plant to go through photosynthesis.
two types of pigments
So first, there are two different types of pigments that can excite electrons, which is what we need to do in these light-dependent reactions. So one of them is chlorophylls. They absorb red and blue light and they reflect green. That's why they show up is green in color. So if you want a plant to grow and you only shined green light on it, it wouldn't grow very well because that lies just going to get reflected. It absorbs red and blue. The best. Plants do have another pigment, a lot of them, they're called carotenoids. And so these will absorb some of that blue light and the green light, okay, and the light that they reflect are yellow, orange, and red. Carotenoids are actually win. The leaves start to change color like now and they turned yellow and red. That's because the chlorophylls are breaking down. So these break down more easily and once they're broken down, they tend to overpower the crowd noise in terms of the color of the leaf. So once these broke, break down, you can just see the carotenoids. And so that's why they turned sort of yellow and orange and red. So combined plants have different combinations of the, so some will have more chlorophyll and there's actually two types of chlorophyll. So some may have more chlorophyll a and some have more chlorophyll b, and some have more carotenoids. That's what makes all the different colors of leaves that you see. So what this is showing you is for different wavelengths of light. So like purple light, yellow light and red light, how much light gets absorbed by a leaf. And you can see the two green lines. This one is labeled a and this one that's labeled B, that's showing you just the chlorophyll and what light it tends to be really good at absorbing CC, the chlorophylls, they're pretty good at absorbing kind of bluish light. And pretty good at absorbing the red light, but not very good at this sort of yellowy green light. And in general, the gray line up here represents when you combine all the carotenoids and chlorophylls we tend to find in plants. This is the light that the plants can use the most to make to do photosynthesis. They're really good at using line over here. That's what the grey showing us. And they're really good at using red light, but they just like green light. They just can't use very well, so it's lower here. And again, if you only put green light on a plant, it just wouldn't survive very well cuz it wouldn't be able to make enough glucose to survive. This is the basic structure, so you don't have to memorize the structure, but I do want you to recognize it. Okay. So chlorophyll, it has a head. The head of the chlorophyll, that's what absorbs the light.
Explain the function of the stomata in the leaf.
Stomata have two main functions, namely they allow for gas exchange acting as an entryway for carbon dioxide (CO2) and releasing the Oxygen (O2) that we breath. The other main function is regulating water movement through transpiration.
What is an electron transport chain What is its role during the light reactions?
The electron transport chain moves protons across the thylakoid membrane into the lumen. At the same time, splitting of water adds protons to the lumen, and reduction of NADPH removes protons from the stroma. The net result is a low pH in the thylakoid lumen, and a high pH in the stroma.
Summarize how the light-capturing reactions and the Calvin cycle transform light energy to chemical energy.
The light reactions capture solar energy and use it to make ATP and transfer electrons from water to NADP+, forming NADPH. They're carried out by molecules in the thylakoid membrane, and split water and release O2 to the oxygen. - The Calvin cycle uses the ATP and NADPH to make sugar from carbon dioxide.
How many ATP and Nadph are produced in light reactions?
The light-dependent reactions convert light energy into chemical energy, producing ATP and NADPH. 5. The light-dependent reactions can be summarized as follows: 12 H2O + 12 NADP+ + 18 ADP + 18 Pi + light and chlorophyll yields 6 O2 + 12 NADPH + 18 ATP.
Describe how an antenna complex works and state the function of the reaction center.
The light-harvesting complex (or antenna complex; LH or LHC) is an array of protein and chlorophyll molecules embedded in the thylakoid membrane of plants and cyanobacteria, which transfer light energy to one chlorophyll a molecule at the reaction center of a photosystem. A photosynthetic reaction centre is a protein that is the site of the light reactions of photosynthesis. The reaction centre contains pigments such as chlorophyll and phaeophytin. These absorb light, promoting an electron to a higher energy level within the pigment.
