Term
| If an enzyme is added to a solution where its substrate and products are in equilibrium, what would occur? |
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Definition
| Nothing; the reaction would stay at equilibrium |
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Term
| Some bacteria are metabolically active in hot springs because? |
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Definition
| their enzymes have high optimal temperatures |
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Term
| What does it mean when we say that organisms are thermodynamically open systems? |
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Definition
| Organisms acquire energy from their surroundings. |
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Term
| Which of the following has the most free energy per molecule? |
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Definition
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Term
| Which compound could most easily be modified to form ATP? |
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Definition
The RNA nucleotide Adenosine.
Adenosine has a ribose sugar attached, one phosphate group, and the nitrogenous base adenine. |
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Term
| Why are the bonds between phosphate groups in ATP unstable? |
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Definition
| The negatively charged phosphate groups repel one another and the terminal phosphate group is more stable in water than it is in ATP. |
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Term
| The formation of glucose-6-phosphate from glucose is an endergonic reaction and is coupled to which of the following reactions or pathways? |
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Definition
The hydrolysis of ATP.
(first hydrolyze ATP, then use the energy released to transfer a phosphate group to glucose) |
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Term
| What does the speed of an enzymatic reaction depend on? |
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Definition
| The speed of a reaction is determined by the activation energy barrier of the reaction and the temperature (which determines how many reactants have the energy to overcome the barrier). |
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Term
| Does increasing the concentration of substrate increase the rate of the reaction? |
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Definition
| Until the enzyme becomes saturated with substrate, increasing the substrate concentration increases the rate of the reaction. |
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Term
| How is enzyme activity affected by PH? |
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Definition
| High or low PH may disrupt hydrogen bonding or ionic interactions and thus change the shape of the active site. |
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Term
| What are the roles of heat and temperature in biological reactions? |
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Definition
1. Heat from the environment is necessary for substrates to get over the activation energy barrier.
2. Increasing temperature increases increases the kinetic energy of the substrates. |
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Term
| In the absence of oxygen, what is the net gain of ATP for each glucose molecule that enters glycolysis? |
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Definition
2 net ATP gained.
(4 produced - 2 consumed) |
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Term
| In most cells, not all of the carbon that enters glycolysis is converted to carbon dioxide by cellular respiration. What happens to this carbon that does not end up as CO2? |
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Definition
| The carbon atoms are removed from these processes to serve as building blocks for other complex molecules. |
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Term
| How many net molecules of ATP does the citric acid cycle produce? |
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Definition
|
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Term
| How many molecules of ATP are formed by the electron transport chain (oxidative phosphorylation)? |
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Definition
|
|
Term
| What is the end result of glycolysis? |
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Definition
| For every glucose molecule that enters glycolysis, a net of 2 ATP and a net of 2 NADH are formed. |
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Term
| Why don't cells do not catabolize carbon dioxide? |
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Definition
| Carbon Dioxide is already completely oxidized. |
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Term
| In glycolysis, what starts the process of glucose oxidation? |
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Definition
|
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Term
| For each glucose that enters glycolysis, ____ NADH and H+ are produced by the citric acid cycle. |
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Definition
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Term
| In fermentation, ____________ is reduced and _______________ is oxidized. |
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Definition
|
|
Term
| Which molecule from the glycolytic pathway has the most chemical energy? |
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Definition
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Term
| In an experiment, mice were fed glucose (C6H12O6) containing a small amount of radioactive oxygen. The mice were closely monitored, and in a few minutes radioactive oxygen atoms showed up in which compound? |
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Definition
|
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Term
| For each glucose molecule that enters glycolysis, how many ATP, NADH, and FADH2 are produced in the citric acid cycle? |
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Definition
|
|
Term
| How many ATP, NADH, and FADH2 are produced for each pyruvate molecule that enters the citric acid cycle? |
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Definition
| In the citric acid cycle, for each pyruvate that enters the cycle, 1 ATP, 3 NADH, and 1 FADH2 are produced. |
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Term
| Which of the following represents the major (but not the only) energy accomplishment of the citric acid cycle? |
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Definition
| formation of NADH and FADH2 |
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Term
| How many molecules of ATP are gained by substrate-level phosphorylation from the complete breakdown of a single molecule of glucose in the presence of oxygen? |
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Definition
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|
Term
| After completion of the citric acid cycle, most of the usable energy from the original glucose molecule is in the form of _____. |
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Definition
|
|
Term
| Which of the following accompanies the conversion of pyruvate to acetyl CoA before the citric acid cycle? |
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Definition
| formation of CO2 and NADH |
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Term
| When a poison such as cyanide blocks the electron transport chain, glycolysis and the citric acid cycle soon grind to a halt as well. Which of the following is the best explanation for this? |
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Definition
NAD+ and FAD are not available for glycolysis and the citric acid cycle to continue.
Unless the electron transport molecules (NADH and FADH2) can recycle back to their oxidized states (NAD+ and FAD), they will be unable to receive electrons in the other steps of cellular respiration. |
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Term
| In glycolysis in the absence of oxygen, cells need a way to regenerate which compound? |
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Definition
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Term
| If muscle cells in the human body consume O2 faster than it can be supplied, which of the following is likely to result? |
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Definition
| Muscle cells would not be able to produce enough ATP to meet demands, oxidative phosphorylation would stop, and muscle cells would consume glucose at an increased rate. |
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Term
| Of the metabolic pathways listed below, which is the only pathway found in all organisms? |
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Definition
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Term
| When protein molecules are used as fuel for cellular respiration, _____ are produced as waste. |
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Definition
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Term
| A gram of fat oxidized by respiration produces approximately twice as much ATP as a gram of carbohydrate. Which of the following best explains this observation? |
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Definition
| Fats are better electron donors to oxygen than are sugars. |
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Term
| If significant amounts of materials are removed from the citric acid cycle to produce amino acids for protein synthesis, which of the following will result? |
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Definition
| Less ATP will be produced by the cell; Less CO2 will be produced by the cell; The four-carbon compound that combines with acetyl CoA will have to be made by some other process. |
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Term
|
Definition
|
|
Term
| Which of the following is produced by the light reactions of photosynthesis and consumed by the Calvin cycle? |
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Definition
|
|
Term
| he overall function of the Calvin cycle is _____ |
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Definition
|
|
Term
| C4 plants occur more commonly in desert conditions because _____. |
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Definition
| they can fix carbon at the lower CO2 concentrations that develop when the stomata are closed |
|
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Term
| What is the end product of the Calvin Cycle? |
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Definition
| To summarize, so far the Calvin cycle has used the energy of the light reactions to reduce three molecules of carbon dioxide and produce one molecule of G3P. The cell can combine two G3Ps to make glucose, which stores the energy that chlorophyll originally captured from the sun. |
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Term
| How much ATP and NADPH is used to make one GP3 molecule? |
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Definition
| To make each G3P, the Calvin Cycle consumes 9 ATP molecules and 6 NADPH molecules. |
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Term
| The light reactions of photosynthesis supply the Calvin cycle with _________. |
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Definition
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|
Term
| Cooperation of the two photosystems is required for _____________. |
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Definition
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|
Term
| In what respect are the photosynthetic adaptations of C4 plants and CAM plants similar? |
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Definition
| In both cases, an enzyme other than rubisco carries out the first step in carbon fixation. |
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Term
| Which of the following processes is most directly driven by light energy? |
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Definition
| removal of electrons from chlorophyll molecules |
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Term
| Which of the following statements is a correct distinction between cyclic and noncyclic electron flow? |
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Definition
| Only cyclic electron flow can operate in the absence of photosystem II. |
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Term
| Plants are photoautotrophs. What does this mean? |
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Definition
1. They make their own food from inorganic materials.
2. They are among the producers of the biosphere.
3. They are in the same category as algae and cyanobacteria.
4. They use light energy to drive the synthesis of organic molecules. |
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Term
| The light reactions of photosynthesis use _____ and produce _____. |
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Definition
|
|
Term
| Energized electrons from ____ enter an electron transport chain and are then used to reduce NADP+. |
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Definition
|
|
Term
| _____ splits water into 1/2 O2, H+, and e-. |
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Definition
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|
Term
| Carbon fixation involves the addition of carbon dioxide to _____. |
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Definition
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|
Term
| After 3-PGA is phosphorylated, it is reduced by _____. |
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Definition
|
|
Term
| How many carbon dioxide molecules must be added to RuBP to make a single molecule of glucose? |
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Definition
| 6. Six carbon dioxide molecules are required to produce two G3P molecules, which can be combined to make one glucose molecule. |
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Term
| In the Calvin cycle, how many ATP molecules are required to regenerate RuBP from five G3P molecules? |
|
Definition
|
|
Term
| In C4 and CAM plants carbon dioxide is fixed in the _____ of mesophyll cells. |
|
Definition
cytoplasm
(In C3 plants, carbon fixation occurs in the stroma of the thylakoid) |
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Term
| C4 plants differ from C3 and CAM plants in that C4 plants _____. |
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Definition
| transfer fixed carbon dioxide to cells in which the Calvin cycle occurs |
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|
Term
| In photosynthesis, what is the fate of the oxygen atoms present in CO2? They end up ______. |
|
Definition
| in sugar molecules and in water |
|
|
Term
| What are the components of a photosystem? |
|
Definition
1. reaction center
2. light harvesting complexes
3. primary electron acceptors |
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|
Term
| During photosynthesis, an electron transport chain is used to _____. |
|
Definition
transport electrons from photosystem II to photosystem I
Correct. Each photoexcited electron passes from the primary electron acceptor of photosystem II to photosystem I via an electron transport chain. |
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Term
| Which one of the following is cycled in the cyclic part of light reactions? |
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Definition
|
|
Term
| Light reactions do all of the following except _____. |
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Definition
|
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Term
|
Definition
| the enzyme in plants that first captures CO2 to begin the Calvin cycle |
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|
Term
| In the Calvin cycle, CO2 is combined _____. |
|
Definition
| with a 5-carbon compound to form an unstable 6-carbon compound, which decomposes into two 3-carbon compounds |
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|
Term
| Glyceraldehyde-3-phosphate is produced in the stroma of chloroplasts. Which of the following statements is true about this compound? |
|
Definition
| It is produced from glucose during glycolysis. |
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