Photosynthesis Flashcard
What is the meaning of "synthesis" in photosynthesis? 138
Segment in which sugar is built.
What happens on "photo" part of photosynthesis? 143
"photo" part, which sunlight hits a plant and, in a three step process, some of the energy in this sunlight is captured and stored in ATP and in another molecule (NADPH) that stores energy by accepting high energy electrons
What do you call the 3 Steps of Calvin Cycle? 146
1. Fixation 2. Sugar Creation 3. Regeneration
Three steps of Cellular Respiration 152
1. Glycolysis 2. Krebs Cycle 3. The Electron Transport Chain
Three inputs to the process of photosynthesis: 138
1. Light energy 2. Carbon Dioxide 3. Water
Once the electron in a photosynthetic pigment is excited to a higher energy states, generally, it will have one of two fates. What are they? 142
1. The electron returns to its resting, unexcited state, releasing energy in the process, some of which may bump electrons in a nearby molecule to a higher energy state. 2. The excited electron itself is passed to another molecule.
2 Distinct phases of Glycolysis? 152
1. Uphill (Preparatory Phase) 2. Downhill (Payoff Phase)
What is Pyruvate? 152
2 molecules of a substance that results from which glucose is broken down.
Define Stroma 139
A sac-shaped organelle that is filled with a fluid. The production of sugar occurs in stroma
Define Chlorophyll 139
A special molecule found in chloroplast that makes the capture of light energy possible.
What is the 3rd step of Cellular Respiration? 156
ATP is built in the electron transport chain.
How do living organisms fuel their actions? 151
Cellular Respiration
Q> Why must plants get water for photosynthesis to occur? 144
Because as electrons keep getting taken away from the special chlorophyll a molecule, the electrons must be replaced, and this replacement comes from water. Molecules of water inside the thykaloid, near the special chlorophyll a molecule in the thylakoid membrane are continuously split. The split-in which 4 photons of light split 2 molecule of O₂-provides the electrons necessary to replenish chlorophyll A's electron supply. A convenient and life sustaining by product of the splitting of water in photosynthesis is the oxygen that is released from the cell, a by-product essential for much of the life on earth, including all animal life.
Why does the chlorophyll a at the second photosystem has electron vacancies? 144
Because as in the first photosystem, when electrons in the special chlorophyll a molecule are boosted to an excited state, they are whisked away from the chlorophyll molecule by another primary electron acceptor. This electron acceptor then passes the electrons to a second electron transport chain.
Why are leaves green? 138
Because the cells near the surface are packed full of chloroplast.
Why is fruit a form of potential energy? 133
Because the chemical energy stored in the chemcal bonds making up the food can be broken and the energy released during cellular respiration, enabling you to run, play, and work.
Why is evaporation a problem for plants? 148
Because water is essential to photosynthesis, growth, and the transport of nutrients, without water, plants cannot live long.
What happens on Uphill phase of Glycolysis? 152
Before any energy can be extracted from glucose, some energy must be added to the molecule. The additional energy (which comes from ATP) destabilizes the glucose molecule, making it ripe for chemical breakdown. Once the glucose can be broken down chemically, the energy stored in its bonds can be harnessed as the bonds are broken.
"Synthesis" part of photosynthesis occur un a series of chemical reactions. What do you call that chemical reactions? 146
Calvin Cycle
How do stomata exchange gas? 148
Carbon dioxide for photosynthesis enters through these openings and oxygen generated as a by product in photosynthesis exits through them.
The Passing of Electrons in Their Excited State 142
Chief way energy moves through cells Molecules that gain electrons always carry greater energy than before receiving them. Can view this as passing of potential energy from molecule to molecule
What happens in Fixation of Calvin Cycle? 146
Enzyme called rubisco is used, plants pluck carbon from the air, where it occurs in the form of carbon dioxide, and then attach, or "fix" it to a visible organic (carbon-containing) molecule within the chloroplast. Note: rubisco is the most abundant protein on earth
Laws of Thermodynamics: 133
First Law of Thermodynamics • Energy cannot be created or destroyed; • it can change from one form to another Second Law of Thermodynamics • When energy is converted from one form to another, some of it is lost as heat • Heat is highly entropic (disorganized)
The Krebs Cycle Outcome 2 154
High-energy electron carriers (NADH) are made and carbon dioxide is exhaled. The 6 carbon molecule (oxaloacetate) then gives electrons to NAD⁺ to make the high energy electron carrier NADH. The 6 carbon molecule releases 2 carbon atoms along with 4 oxygen atoms to form 2 carbon dioxide molecules. (In mammals, this CO₂ os carried by the bloodstream to the lungs, from where it is exhaled into the atmosphere.
What does The Krebs Cycle do? 154
In the mitochondria, the molecules produced from the breakdown of glucose during glycolysis are broken down further, during two steps that are dramatically more efficient at capturing energy. In the breaking down the products of glycolysis, the Krebs Cycle Produces some additional molecules of ATP and, more importantly, captures a huge-energy electron carriers.
Where does Calvin Cycle reactions occur? 146
In the stroma of the leaves' chloroplasts, outside the thylakoids.
Define Thylakoids 139
Interconnected membranous structure that floats in the stroma. The "photo" part of photosynthesis occurs inside thykaloids.
Where does the 1st step of electron transport chain begins? 157
It begins with NADH and FADH₂ in the mitochondrial matrix moving to the membrane. The high-energy electrons they carry are transferred to molecules embedded within the membrane. After they donate their electrons, the molecules that remain, NAD⁺ and FAD, are recycled back to the Krebs Cycle.
Q> When humans grow, the new tissue comes from the food we eat. When plants grow, where does the new tissue come from? 137
It comes from an invisible gas in the air. How is this possible? photosynthesis. Plants capture carbon dioxide gas from the air, and it also uses the energy they get from sunlight, along with water and small amounts of chemicals found in soil. As a result, they produce solid, visible sugars and other organic molecules that are used to make plants structures like leaves, roots, flowers, fruits, etc.
What is NADPH? 146
It is the second important product of the "photo" portion of photosynthesis.
What is the "Synthesis" part of photosynthesis 146
It is when the energy from the sunlight is captured and convert it to food.
What will happen once the primary electron acceptor gets hold of the high-energy electrons from chlorophyll a? 144
It passes them along like hot potatoes to another molecule, which passes them to another, which passes them to yet another. (This process is called electron transport chain)
What is the Disadvantage of C4 photosynthesis? 149
It requires more energy. Every time the plant will produce the CO₂-sticky tape enzyme, it uses one molecule of ATP, but to use this amount of energy is only acceptable only when the climate is so hot and dry that the plant would otherwise have to close its stomata and completely shut down all sugar production If the Climate is mild however, plants conducting the more energetically expensive C4 photosynthesis would be out-competed by the more efficient plants conducting standard photosynthesis.
If plants only captures tiny bit of energy from the sun, what happens to the rest? 133
It's reflected back into space (about 30%), absorbed by land, the oceans, and the atmosphere (about 70%) and mostly transformed into heat.
Each energy burst boosts chlorophyll's electrons to an excited state, but the chlorophyll a molecule at the center of the photosystem is a special, differing from the other pigment molecules in one key feature; what is it? 143
Its electrons that are boosted to an excited state does not return to their resting, unexcited state. Instead, the special chlorophyll a continually loses its excited electrons to a nearby molecule, called the primary electron acceptor, which acts like an electron vacuum.
Acetyl-CoA Production, Preparation for The Krebs Cycle. 154
Modification 1. Each pyruvate molecule passes a pair of its high-energy electrons (and a proton) to the electron-carrier molecule NAD⁺, building 2 molecule of NADH Modification 2. Next, a carbon atom and 2 oxygen atoms are removed from each pyruvate mplecule and released as carbon dioxide. The CO₂ molecules diffuse out of the cell and, eventually, out of the organism. In humans, for examole, these CO₂ molecules pass into the bloodstream and are transported to the lungs, from which they are eventually exhaled. Modification 3. Final step, The preparation for the Krebs cycle, a giant compound known as coenzyme A attaches itself to the remains of each pyruvate molecule, producing 2 molecules called acetyl-CoA. Each acetyl-CoA molecule is now ready to enter the Krebs cycle.
High-Energy electron carriers that ultimately generates the largest amount of usable energy as ATP 156
NADH and FADH₂
What happens in Regeneration of Calvin Cycle? 146
Note: Not all G3P molecules are used to produce sugars. Some G3P molecules are used to regeneratethe original molecule in the chloroplast to which the carbon CO₂ is attached. This regeneration process requires energy from ATP produced in the "photo" reaction of photosynthesis. With this regeneration, The Calvin Cycle can continue to fix carbon and produce molecules of G3P. Ultimately, to synthesize one molecule of G3P, the Calvin Cycle must fix 3 atoms of carbon from carbon dioxide to the initial organic molecule; this process consumes 9 molecule of ATP and six molecules of NADPH generated in the "photo" reactions of photosynthesis.
What limits the rate at which the mitochondria can break down fuel and produce ATP? 159
Oxygen deficiency. When our bodies fall behind in delivering oxygen from the lungs to the bloodstream to the cells and finally to the mitochondria, Oxygen deficiency occur.
When close, what can Stomata allow to happen 148
Oxygen from the "photo" reactions of photosynthesis cannot be released from the chloroplast, and carbon dioxide cannot enter.
What is the meaning of "photo" in photosynthesis? 138
Photo includes the segment where light is captured.
What is the function of the electron transport chain? 144
Physically links the first photosystem to the second, and as the traveling electrons continue their journey, they fill electron vacancies in the reaction center of the second photosystem, right next to the first photosystem.
What happens on C4 Photosynthesis? 148
Plants add an extra set of steps to usual process photosynthesis: The plants produce an enzyme that functions like the ultimate "CO₂-sticky tape", and this enzyme has a tremendously strong attraction for carbon dioxide; it can find and bind carbon even when CO₂ concentration is very low.
How do Cellular Respiration work? 152
Plants and animals break down the chemical bonds of sugar and other energy-rich food molecules (Such as fats and proteins) to release the energy that went into creating them.
What happens during "photo" reaction? 138
Plants capture the light energy and temporarily saved in energy-storage molecule, and during this process, water molecules split and produce oxygen.
How do CAM photosynthesis work? 150
Plants close their stomata during hot, dry days. At nightm they open the stomata and let CO₂ into the leaves, where it binds temporarily to a holding molecule. During the day, when a carbon source is needed to make sugars in the Calvin Cycle, the CO₂ is gradually released from the holding molecule, enabling photosynthesis to proceed while keeping the stomata closed to reduce water loss.
Define Photosynthesis 131
Process by which plants capture light from the sun and store it in the chemical bonds of sugar and other food molecules they make.
Explain Mitochondria's Feature 1, "Bag within a bag" 156
The "Bag Within a Bag" feature makes it possible for a concentration gradient to form between the regions inside and outside the "inner bag" and makes it possible to harness the potential energy in the bond of NADH and FADH₂ molecules to produce ATP.
Before Krebs Cycle can occur, what does the end products of glycolysis have to do? 154
The 2 molecules of pyruvate must be modified. First, the pyruvate molecules movefrom the cytoplasm into the mitochondria, where they undergo 3 quick modifications that prepare them to be broken down in the Krebs cycle.
What do you call the 2nd step of Cellular Respiration? 154
The Krebs Cycle, which extracts energy from sugar.
What wil happen to the electron as each step in the electron transport chain's sequence of electron handoffs? 144
The electron fall to a lower energy state and a little bit of energy is released. These bits of energy are harnessed to power pumps in the thylakoid membrane that move protons from the stroma to the inside of the thylakoid.
What will happen at the end of the electron transport chain? 145
The electrons are passed to a molecule called NADP⁺, creating NADPH, a high-energy electron carrier.
What happens during "synthesis" reaction? 138
The energy that is stored in energy-storage molecule is used to assemble sugar molecules from carbon dioxide from the air.
What happens on step 2 of electron transport chain? 157
The lower-energy electrons are handed off to oxygen, which then combines with free H⁺ ions in the mitochondrial fluid to form water.
What can the membrane-embedded molecules do? 157
The membrane-embedded molecules pass the electrons to the next carrier, which passes the electrons to the next, and so on. At each pass, a bit of energy is released, so as electrons move from one carrier to another through the electron transport chain, they lose energy at each handoff.
What happens in Sugar Creation of Calvin Cycle? 146
The newly built molecule is chemically modified: A phosphate from ATP is added, and the molecule receives some high-energy electrons from NADPH. This product of the Calvin Cycle is a small sugar called glyceraldehyde 3-phosphate (G3P). Some of the G3P molecules are combined to make the six-carbon sugars glucose and fructose. These sugars can be used as fuel by the plant, enabling it to grow. They can also be used as fuel by animals that eat the plant.
Define Cell Respiration. 131
The process by which all living organisms release the energy stored in the chemical bonds of food molecules and use it to fuel their lives.
What will happen once Hydrogen ions are inside the thylakoid sac? 144
The pumps pack the protons inside the thylakoid sac at higher and higher concentrations. Then the protons eventually rush out of the thylakoid sacs with great force-and the force of the protons moving down their concentration gradient is harnessed to build energy-storing ATP molecules, one of the two products of the "photo" portion of photosynthesis
The Krebs Cycle Outcome 3 155
The starting material of the Krebs Cycle is re-formed, ATP is generated, and more high energy electron carriers are formed. After the CO₂ is released, the 4 carbon molecule that remains from the original pyruvate oxaloaccetate molecule formed i outcome 1 is modified and rearranged to once again form oxaloaccetate, the starting material of the Krebs Cycle. In the process of this re-organization, 1 ATP molecule is generated and more electrons are passed to one familiar high-energy electron carrier, NADH, and a new one, FADH₂. The formation of these high-energy electron carriers increases the energy yield of the Krebs Cycle. One oxaloacetate is re-formed, and the cycle is ready to break down the 2nd molecule of acetyl-Coa. 2 turns of the cycle are necessary to completely dismantle our original molecule of glucose.
What does Mitochondria do in terms of energy? 156
The structure of mitochondria makes possible their impressive ability to harness energy from food molecules
How do plants carry this reaction? 146
Using the energy stored in the ATP and NADPH molecules that are built in the "photo" portion of photosynthesis.
What is the Disadvantage of CAM photosynthesis? 150
When by completely closing their stomata during the day, CAM plants significantly reduce the total amount of CO₂ they can take in. So, they have much slower growth rates and cannot compete well with non-CAM plants under any conditions other than extreme dryness.
The Krebs Cycle. Outcome 1 154
When the new molecule is formed, Acetyl-CoA, it adds its 2 carbon acetyl group to a molecule of the starting material of the Krebs cycle, a 4 carbon chemical called oxaloacetate, and it creates a 6 carbon molecule.