What are some examples of coenzymes?
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Examples of coenzymes include adenosine triphosphate (ATP), cobalamins, and coenzyme A.
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What are some examples of coenzymes?
Examples of coenzymes include adenosine triphosphate (ATP), cobalamins, and coenzyme A.
What is cellular respiration?
Cellular respiration is the process by which cells extract and use the energy contained in organic compounds.
What is the process of oxidative phosphorylation?
ADP + Pi → ATP
What is produced from the oxidation of 2 pyruvate?
2 acetyl CoA
What is the proton (H+) gradient in the context of chloroplasts?
The concentration of protons in the thylakoid space is higher than the concentration in the stroma.
What is chemiosmosis?
Chemiosmosis is the process by which ATP is produced in the mitochondria and chloroplasts, utilizing the energy from the proton gradient created by electron transport chains.
What is formed when O2 captures electrons and protons in the electron transport chain?
O2 captures the electrons along with H+ to form H2O.
What happens to electrons from glucose during cellular respiration?
Electrons from glucose are transferred to electron shuttles (NAD+ → NADH and FAD → FADH2), which donate electrons to the electron transport chain (ETC) and create a H+ gradient that leads to ATP production.
What enters the Calvin cycle and is reduced to a three-carbon sugar?
CO2 enters the cycle and is reduced to glyceraldehyde 3-phosphate.
How much ATP does the oxidation of one gram of fat produce compared to one gram of carbohydrate?
The oxidation of one gram of fat produces twice as much ATP as one gram of carbohydrate.
What process do fatty acids undergo to form acetyl coA?
Fatty acids undergo beta oxidation to form acetyl coA.
What role does the reaction center play in photosystems?
The reaction center contains a pair of chlorophyll a molecules and a primary electron acceptor that removes the excited electron from chlorophyll.
What is the net yield of glycolysis per glucose molecule?
The net yield per glucose is 2 ATP, 2 NADH, and 2 pyruvate.
How many ATP are produced by substrate level phosphorylation in glycolysis and Krebs cycle?
4 ATP.
How do protons behave in the electron transport chain during cellular respiration?
Protons are pumped into the intermembrane space, creating a high concentration that flows down their gradient into the matrix, releasing energy used to phosphorylate ADP to ATP.
What is the primary function of the light-dependent reactions in photosynthesis?
To convert solar energy to chemical energy, occurring in the thylakoids.
What is the total ATP produced from one glucose molecule during cellular respiration?
32 ATP.
What role does NADPH play in the Calvin cycle?
NADPH carries high energy electrons which are used as reducing power in the Calvin cycle.
What is the main purpose of the Calvin cycle?
To convert CO2 into sugar, occurring in the stroma.
What are the products of glycolysis from one glucose molecule?
2 pyruvate (3C), 2 ATP, and 2 NADH.
What does the Krebs Cycle oxidize acetyl CoA to?
4 CO2
What is the definition of chemiosmosis according to Campbell?
An energy-coupling mechanism that uses energy stored in the form of a H+ ion gradient across a membrane to drive cellular work, such as the synthesis of ATP.
What are the main pigments involved in photosynthesis?
Chlorophyll a, chlorophyll b, and carotenoids.
What happens to electrons as they move through each complex in the electron transport chain?
The electrons drop in free energy, and the energy released is used to pump protons from the matrix into the intermembrane space, producing an electrochemical gradient.
How is AMP related to ADP and ATP?
AMP (Adenosine Monophosphate) is formed when ADP loses another phosphate group, and it can be converted back to ADP and ATP.
What does reduction mean in the context of redox reactions?
Reduction means gain of electrons.
What happens to excited electrons in cyclic electron flow?
They cycle from the reaction center to a primary acceptor along an electron transport chain.
Where does the phosphorylation of ADP to ATP occur in cellular respiration?
The phosphorylation of ADP to ATP occurs in the matrix.
How does fermentation differ from respiration?
In fermentation, NAD+ is produced from NADH without ATP production, and the final electron acceptor is pyruvate or acetaldehyde, whereas in respiration, the final electron acceptor is oxygen.
What is the role of oxygen in cellular respiration?
Oxygen acts as the final electron acceptor in the electron transport chain, allowing for the production of ATP.
What is the total amount of CO2 released from one glucose molecule during the Krebs Cycle?
6 CO2 are released from one glucose molecule during the Krebs Cycle.
What is the overall process of cellular respiration?
Oxidation of organic compounds + O2 → CO2 + H2O + energy (e.g., C6H12O6 + 6O2 → 6CO2 + 6H2O + energy). Energy is released as electrons move from organic compounds to O2, the final electron acceptor in respiration.
What inhibits phosphofructokinase in cellular respiration?
High ATP and citrate produced by the Krebs cycle inhibit phosphofructokinase.
What two processes does chemiosmosis couple?
What happens when protons fall back down their gradient?
This process is exergonic.
What is the role of coenzyme A in the Krebs cycle?
Coenzyme A is involved in the first step of the Krebs cycle, particularly in the introduction of the acetyl group into the cycle for energy production.
What is the Electron Transport Chain (ETC) and where is it located?
The Electron Transport Chain (ETC) is embedded in the inner mitochondrial membrane and is comprised of enzyme complexes that serve as electron carriers.
What happens to electrons after they pass from the primary electron acceptor to PSI?
They travel via an electron transport chain (ETC), falling to a lower energy state in a stepwise manner, releasing energy used to produce ATP by photophosphorylation.
What type of process is involved when ADP receives an inorganic phosphate group to form ATP?
This process is endergonic.
What does ATP stand for?
Adenosine Triphosphate.
What are the total products generated from one glucose molecule during cellular respiration?
6 CO2 and 32 ATP.
What happens to protons during the electron transport chain in photosynthesis?
Protons are pumped into the thylakoid space, creating a high concentration that flows down their gradient into the stroma, releasing energy used to phosphorylate ADP to ATP.
What is produced when water is split during the light-dependent reactions?
2 electrons, 2 hydrogen ions, and 1/2 oxygen molecule.
Where does glycolysis occur?
Glycolysis occurs in the cytoplasm of the cell.
What is oxidative phosphorylation?
Oxidative phosphorylation is the final stage of cellular respiration where ATP is produced using the energy from electron transport and chemiosmosis.
How many NADH are produced from one glucose molecule during the Krebs Cycle?
10 NADH are produced from one glucose molecule during the Krebs Cycle.
What percentage of cellular ATP is formed during oxidative phosphorylation?
90% of the cellular ATP (26 - 28 moles).
What activates phosphofructokinase in response to cellular metabolic needs?
Low ATP and high AMP activate phosphofructokinase.
What type of process occurs when protons are pumped against their gradient?
This process is endergonic.
What are photosystems composed of?
Photosystems are composed of an antenna complex with several hundred chlorophyll molecules and a reaction center containing a pair of chlorophyll a molecules.
What are the three key molecules involved in energy transfer in cells?
AMP, ADP, and ATP.
Why is cyclic electron flow important for the Calvin cycle?
It makes up the difference in ATP usage since the Calvin cycle uses more ATP than NADPH.
What does oxidation mean in the context of redox reactions?
Oxidation means loss of electrons.
What role does ATP synthase play in ATP production?
ATP synthase allows protons to diffuse back across the membrane, which is an exergonic process that fuels the endergonic process of ATP synthesis.
What is fermentation?
Fermentation is the anaerobic catabolism of organic nutrients, producing ATP in the absence of O2, primarily through glycolysis.
Where are chloroplasts mainly found?
Chloroplasts are mainly found in mesophyll cells.
How is ATP produced during the light-dependent reactions?
ATP is produced by photophosphorylation, where ADP and inorganic phosphate combine to form ATP.
Where does glycolysis occur?
In the cytoplasm.
Where does the Krebs cycle take place?
In the mitochondrial matrix.
What are the two processes that comprise photosynthesis?
Photosynthesis is comprised of light-dependent reactions and the Calvin cycle.
What are the two types of photosystems in photosynthesis?
What do NADH and FADH2 do in cellular respiration?
NADH and FADH2 donate electrons to the electron transport chain (ETC) after being reduced from NAD+ and FAD, respectively.
Where are pigments embedded in plant cells?
In thylakoid membranes.
What happens when pigments absorb photons?
Electrons get elevated to an excited state.
What does cyclic electron flow produce?
Only ATP.
What happens to the electron when it is absorbed by the photosystems?
It goes to a higher energy state and gets trapped by the primary electron acceptor.
How is ATP produced in the electron transport chain?
ATP is produced by oxidative phosphorylation using the energy released during the resolution of the electrochemical gradient.
How does the free energy of FADH2 compare to that of NADH?
FADH2 has a lower free energy than NADH, meaning electrons enter the electron transport chain at a lower energy point.
What range of visible light is used in photosynthesis?
Photosynthesis uses visible light in the range of 400 - 700 nm.
What generates the proton gradient used in ATP production?
The proton gradient is generated by the electron transport chain (ETC).
What unique features do chloroplasts have?
Chloroplasts contain their own DNA and ribosomes, and are surrounded by a double phospholipid bilayer.
What does the stroma of chloroplasts contain?
The stroma contains photosynthetic enzymes and thylakoid membrane sacs.
What is regenerated at the end of the Calvin cycle?
The starting materials needed for the cycle to continue.
What is the total ATP production from one glucose molecule?
32 ATP.
What is substrate level phosphorylation?
Substrate - phosphate + ADP → ATP + substrate - occurs in glycolysis and the Krebs cycle
What is the role of NADP+ in photosynthesis?
NADP+ is the final electron acceptor, and it is reduced to NADPH by accepting electrons and protons.
What can cellular respiration extract energy from besides carbohydrates?
Cellular respiration can extract energy from other organic molecules, such as fats.
What is the energy source used in the Calvin cycle?
ATP is the energy source in the Calvin cycle.
What acts as the reducing agent in the Calvin cycle?
NADPH is the reducing agent in the Calvin cycle.
How is the proton gradient created in the thylakoid space?
The proton gradient is created in three ways: 1) Water is split and protons are released into the thylakoid space, 2) Protons are pumped into the thylakoid space when electrons are transported, 3) Protons in the stroma are removed when NADP+ is reduced to NADPH.
What are the two main products of the light reactions in photosynthesis?
ATP and NADPH
How can light be described in terms of its nature?
Light can be considered as a wave or photons, which are discrete packages of energy.
Where is ATP synthase located?
ATP synthase is embedded in the inner mitochondrial membrane.
How do electrons behave during photosynthesis?
The electrons increase in potential energy as they move from water to sugar.
What are the two types of fermentation?
The two types of fermentation are alcohol fermentation, which occurs in yeast and some bacteria, and lactic acid fermentation, which occurs in human muscles during exercise and in some bacteria.
How much more ATP does cellular respiration yield compared to fermentation?
Cellular respiration yields 16 times more ATP per glucose than fermentation.
What is produced during fermentation?
Fermentation produces ATP along with byproducts such as lactic acid or ethanol, depending on the type of fermentation.
What is the process called when electrons move through the electron transport chain?
This process is exergonic.
What enzyme is responsible for the reduction of NADP+ to NADPH?
The enzyme responsible is NADP+ reductase.
What type of reaction is photosynthesis?
Photosynthesis is a redox reaction.
What is the process of ATP production from ADP and Pi?
ATP is produced from ADP and Pi using the enzyme ATP synthase, which is embedded in the inner mitochondrial membrane. The energy for this process comes from the proton gradient generated by the electron transport chain (ETC).
What replaces the electrons lost from P680 in Photosystem II?
Electrons from water.
What is the role of the electron in cyclic electron flow?
The electron cycles back to fill the e- hole in the P700 chlorophyll molecule.
What molecule does acetyl coA bind with to form citrate in the Krebs Cycle?
Acetyl coA binds with oxaloacetate to form citrate.
What is released as carbon atoms are removed in the Krebs Cycle?
Carbon atoms are released as CO2.
What is the total ATP produced from one glucose molecule after the Krebs Cycle?
The total ATP produced from one glucose molecule after the Krebs Cycle is 4.
Where do the electron transport chain (ETC) and oxidative phosphorylation occur?
In the inner mitochondrial membrane.
What is the function of the antenna complex in photosystems?
The antenna complex absorbs photons and passes energy from chlorophyll to chlorophyll.
What occurs after an electron returns to its ground state?
It gives off energy.
What are the two phases of glycolysis?
What is the process called that resolves the electrochemical gradient produced in the electron transport chain?
The process is called chemiosmosis.
What is the first phase of the Calvin Cycle?
Carbon Fixation, where three CO2 enter the cycle and are attached to ribulose bisphosphate by the enzyme Rubisco.
What happens during the Reduction phase of the Calvin Cycle?
3-phosphoglycerate receives a phosphate group from ATP to form 1,3-bisphosphoglycerate, which is then reduced to glyceraldehyde 3-phosphate (G3P) by NADPH.
What is cellular respiration?
Cellular respiration is the process by which cells convert glucose and oxygen into energy, carbon dioxide, and water.
Which colors of light are the most effective for photosynthesis?
Red and blue light are the best for photosynthesis.
How many molecules of G3P are produced from three CO2 in the Calvin Cycle?
Six molecules of G3P are produced from three CO2 and three ribulose bisphosphate.
How is ATP produced in the Krebs Cycle?
ATP is produced by substrate-level phosphorylation, with GDP converting to GTP as an intermediate step.
How many ATP molecules are produced from one glucose molecule during cellular respiration?
Up to 38 ATP molecules can be produced from one glucose molecule during cellular respiration, depending on the efficiency of the process.
What does noncyclic (linear) electron flow produce?
ATP and NADPH
Which photosystems are involved in noncyclic electron flow?
Photosystems II and I
Which photosystem is involved in cyclic electron flow?
Only PS I.
Does cyclic electron flow produce NADPH or oxygen?
No, it generates ATP without producing NADPH or oxygen.
Where does the phosphorylation of ADP to ATP occur in photosynthesis?
The phosphorylation of ADP to ATP occurs in the stroma.
What are the main stages of cellular respiration?
The main stages of cellular respiration are glycolysis, the Krebs cycle, and oxidative phosphorylation.
What happens to electrons during the Krebs Cycle?
Electrons are removed from acetyl coA to reduce NAD+ to NADH and FAD to FADH2.
What is the first step of the Calvin cycle?
Carbon fixation, where CO2 is converted into organic material.
What happens during pyruvate oxidation?
2 pyruvate are converted to 2 acetyl CoA (2C), producing 2 CO2 and 2 NADH.
What is the role of ADP in cellular energy?
ADP (Adenosine Diphosphate) is formed when ATP loses a phosphate group, releasing energy for cellular processes.
What occurs in Photosystem II when water splits?
Water splits into ½ O2, 2H+, and 2e-.
What is the relationship between energy and wavelength in light?
The energy is inversely proportional to the wavelength.
What is the ATP yield from FADH2 during oxidative phosphorylation?
3 ATP (1.5 ATP each for 2 FADH2).
How many ATP are produced during fermentation?
Fermentation produces 2 ATP per glucose molecule, generated only by glycolysis.
What supplies the energy for photosynthesis?
Light supplies the energy for this process.
What is the permeability of the outer and inner membranes of chloroplasts?
The outer membrane is very permeable, while the inner membrane has selective permeability.
What happens to the organic material in the Calvin cycle?
It is reduced to sugar using NADPH as the electron source.
What is the pulling force in the electron transport chain?
O2, because it is highly electronegative.
What role does ATP synthase play in ATP production?
ATP synthase is a protein embedded in the thylakoid membrane that catalyzes the reaction ADP + Pi → ATP, using the energy from the resolution of the proton gradient.
What are the important effects of the phosphorylation of glucose in glycolysis?
The phosphorylation of glucose makes it more reactive and traps it in the cell when it is charged.
How many NADH are produced, and how much ATP do they yield through the electron transport chain?
10 NADH, yielding 25 ATP (2.5 ATP each).
What happens to water during photosynthesis?
Water is split, and electrons and H+ are transferred to CO2, reducing it to sugar.
What occurs in the Regeneration of Ribulose bisphosphate phase?
One G3P exits the cycle while five G3P are used to regenerate ribulose bisphosphate, requiring additional ATP.
What is the role of Rubisco in the Calvin Cycle?
Rubisco is the enzyme that attaches CO2 to ribulose bisphosphate during the Carbon Fixation phase.
What is the primary purpose of the Krebs cycle?
The primary purpose of the Krebs cycle is to produce electron carriers (NADH and FADH2) that are used in the electron transport chain.
What are thylakoids and how are they organized?
Thylakoids are membrane sacs that may be stacked into grana and contain chlorophyll.
What are the products of the Krebs cycle from 2 acetyl CoA?
4 CO2, 2 ATP, 6 NADH, and 2 FADH2.
What is the overall equation for photosynthesis?
6CO2 + 12H2O + light → C6H12O6 + 6O2 + 6H2O
What is the role of CO2 in photosynthesis?
CO2 serves as the carbon source.