Cell Biology Questions
Explore questions in the Cell Biology category that you can ask Spark.E!
Both mitochondria and chloroplasts __________.release oxygen as a by-productobtain electrons from waterreduce NAD+, forming NADPare surrounded by a single membraneuse chemiosmosis to produce ATP
Which of the following is cycled in the cyclic variation of the light reactions?ElectronsATPNADPHRibulose bisphosphateProtons
The DNA-containing region of this bacterial cell is indicated by the letter _____.http://session.masteringbiology.com/problemAsset/1100503/4/2701q.jpg1. A2. B3. C4. D5. E
You could distinguish a thylakoid membrane from an inner mitochondrial membrane because the thylakoid membrane would __________.have photosynthetic pigmentscontain protein but not lipidsfunction in energy transformationbe inside a mitochondrionhave all of the listed characteristics
The light reactions of photosynthesis generate high-energy electrons, which end up in __________ through linear electron flow. The light reactions also produce __________ and __________. water; sugar; oxygenATP; NADPH; oxygenoxygen; sugar; ATPchlorophyll; ATP; NADPHNADPH; ATP; oxygen
During photosynthesis in a eukaryotic cell, an electrochemical gradient is formed across the __________.cristaethylakoid membranestomatachloroplast outer membranechloroplast inner membrane
Where do the electrons entering photosystem II come from?Chlorophyll molecules in the antenna complexLightATPThe electron transport chainWater
The energy used to produce ATP in the light reactions of photosynthesis comes from __________.splitting watermovement of H+ through a membranethe oxidation of sugar moleculesfluorescencecarbon fixation
Which of the following occurs during the Calvin cycle?-ATP is reduced, and NADPH is oxidized.-Light energy is converted to chemical energy.-Linear electron flow produces the materials required for the fixation of carbon from carbon dioxide.-ATP is oxidized, and NADPH is reduced.-ATP is hydrolyzed, and NADPH is oxidized.
When chloroplast pigments absorb light, __________.the Calvin cycle is triggeredthe pigments' electrons become excitedthe pigments' photons become excitedthe pigments become reducedthe pigments lose potential energy
The most important role of pigments in photosynthesis is to __________.capture light energycatalyze the hydrolysis of waterscreen out harmful ultraviolet rayscatalyze the synthesis of ATPstore energy
Most of the electrons removed from glucose by cellular respiration are used for which of the following processes?Reducing NAD+ to NADH in glycolysis and the citric acid cycleProducing a proton gradient for ATP synthesis in the mitochondriaDriving substrate-level phosphorylation in glycolysisThe first two choices are correct.The second and third answers are correct.
What is the role of NADP+ in photosynthesis?-It is reduced and then carries electrons to the Calvin cycle.-It acts as the primary electron acceptor for the photosystems.-It assists chlorophyll in capturing light.-As a component of photosystem II, it catalyzes the hydrolysis of water.-As part of the electron transport chain, it manufactures ATP.
Which of these statements about enzyme inhibitors is true?-Inhibition of enzyme function by compounds that are not substrates is something that only occurs under controlled conditions in the laboratory.-The action of competitive inhibitors may be reversible or irreversible.-A noncompetitive inhibitor does not change the shape of the active site.-When the product of an enzyme or an enzyme sequence acts as its inhibitor, this is known as positive feedback.-A competitive inhibitor binds to the enzyme at a place that is separate from the active site.
A photon of which of these colors would carry the most energy?GreenRedYellowBlueOrange
Enzyme activity is affected by pH because __________.-changes in pH can cause loss of cofactors from the enzyme-low pH will denature all enzymes-high or low pH may disrupt hydrogen bonding or ionic interactions and thus change the shape of the active site-the binding of hydrogen ions to the enzyme absorbs energy and thus there may not be enough energy to overcome the activation energy barrier-most substrates do not function well at high or low pH
Energy for synthesizing ATP is obtained by ATP synthase directly from which of the following processes?-The flow of H+ across the inner mitochondrial membrane through the ATP synthase enzyme-The oxidation of glucose-The movement of electrons through a series of carriers-The oxidation of NADH and FADH2-The reduction of oxygen
Which of the following best describes the electron transport chain?-Glucose is broken down to a three-carbon compound in preparation for the citric acid cycle.-Acetyl CoA is fully oxidized to CO2.-Electrons are passed from one carrier to another, releasing a little energy at each step.-Hydrogen atoms are added to CO2 to make an energy-rich compound.-Electrons are pumped across a membrane by active transport.
Which of the following substances is/are involved in oxidative phosphorylation?ADPOxygenATPNone of the listed responses is correct.The first three listed substances
During aerobic respiration, molecular oxygen (O2) is used for which of the following purposes?-At the end of the electron transport chain to accept electrons and form H2O-At the end of glycolysis to oxidize pyruvate-As a source of O2 in every reaction that produces CO2-At the end of the citric acid cycle to regenerate citric acid-Between glycolysis and the citric acid cycle to split a carbon from pyruvate, producing CO2