photosynthesis Moodle quiz

Chemiosmosis involves the movement of what? Where does it occur? a. Hydrogen atoms across a mitochondrial membrane b. Hydrogen ions across a mitochondrial membrane c. Electrons across the cell membrane d. Glucose through the cell membrane

b

During the second half of glycolysis, what occurs? a. Fructose is split in two. b. ATP is produced. c. ATP is used up. d. Glucose becomes fructose.

b

As temperatures increase, gases such as CO2 diffuse faster. As a result, plant leaves will lose CO2 at a faster rate than normal. If the amount of light impacting on the leaf and the amount of water available is adequate, predict how this loss of gas will affect photosynthesis in the leaf. a. Loss of gases, mainly CO2 , will not affect photosynthesis in the leaf, as storedreservoirs of CO2 in the leaf can be utilized in such times. b. Loss of gases, mainly CO2 , will affect photosynthesis in the leaf, as the Calvin cycle willbecome faster to compensate for the loss. c. Loss of gases, mainly CO2 , will not affect photosynthesis in the leaf, as adequateamounts of water and light are still present which will let the Calvin cycle runsmoothly. d. Loss of gases, mainly CO2 , will affect photosynthesis in the leaf, as the Calvin cycle willslow down and possibly stop because of inadequate carbon to fix in the system.

d

How do membranes in chloroplasts contribute to the organelles' essential functions? a. The inner membrane contains the chemicals needed for the Calvin cycle, components of the light-dependent reactions, and photosystems I and II. The thylakoid membrane contains the enzyme NAD+ reductase. b. The inner membrane contains components of the light-dependent reactions as well as photosystems I and II. The thylakoid membrane contains the chemicals needed for the Calvin cycle and the enzyme NAD+ reductase. c. The inner membrane contains only the chemicals needed for the Calvin cycle. The thylakoid membrane contains components of the light-dependent reactions,photosystems I and II, and the enzyme NAD+ reductase. d. The inner membrane contains the chemicals needed for the Calvin cycle and components of the light-dependent reactions. The thylakoid membrane contains photosystems I and II, as well as the enzyme NAD+ reductase.

d

What are the products of alcohol fermentation? a. Pyruvic acid and NADH b. Lactic acid and FAD+ c. Methane and NADH d. Ethanol and NAD+

d

What is ATP made from? a. The conversion of guanine to adenosine b. AMP + ADP c. Adenosine + high-energy electrons d. ADP + pyrophosphate

d

What is the function of an electron in the electron transport chain? a. To dephosphorylate ATP, producing ADP b. To reduce heme in complex III c. To oxidize oxygen d. To power active transport pumps

d

What is the overall outcome of the light reactions in photosynthesis? a. NADPH and ATP molecules are produced during the light reactions and are used topower the light-dependent reactions. b. Carbon dioxide and NADPH are produced during the light reactions and are used topower the light-dependent reactions. c. Sugar and ATP are produced during the light reactions and are used to power thelight-independent reactions. d. NADPH and ATP molecules are produced during the light reactions and are used topower the light-independent reactions.

d

Where is the electron transport chain located? a. The mitochondrial matrix b. The cytosol c. A eukaryotic plasma membrane d. The inner mitochondrial membrane

d

Which fermentation method can occur in animal skeletal muscles? a. Propionic fermentation b. Mixed acid fermentation c. Alcohol fermentation d. Lactic acid fermentation

d

Which of the following is the best way to judge the relative activation energies between two given chemical reactions? a. Compare the ΔG values between the two reactions. b. Compare their ideal environmental conditions. c. Compare the spontaneity between the two reactions. d. Compare their reaction rates.

d

Which organism is a heterotroph? a. Kelp b. Cyanobacterium c. Pond algae d. Intestinal bacterium

d

Which structure is NOT a component of a photosystem? a. Primary electron acceptor b. Antenna molecule c. Reaction center d. ATP synthase

d

Why does it take three turns of the Calvin cycle to produce G3P, the initial product of photosynthesis? a. To produce RuBisCO as an end product b. To fix enough oxygen to export one G3P molecule c. To produce ATP and NADPH for fixation of G3P d. To fix enough carbon to export one G3P molecule

d

Why is it beneficial for cells to use ATP rather than directly use the energy stored in the bonds of carbohydrates to power cellular reactions? What are the greatest drawbacks to harnessing energy from the bonds of several different compounds? a. ATP is readily available to cells, unlike compounds that have to first be phosphorylated to release their energy. b. ATP is low in energy, but food molecules possess higher levels of energy that cells can use. c. ATP energy cannot activate the ROS-dependent stress response, whereas food molecules are responsible for activating ROS. d. ATP is readily available in the form of a single unit that provides a consistent,appropriate amount of energy. The cell would need to tailor each reaction to each energy source if it harvested energy from different compounds.

d

Cellular respiration breaks down glucose and releases carbon dioxide and water. Which step in the oxidation of pyruvate produces carbon dioxide? a. Removal of a carboxyl group from pyruvate releases carbon dioxide. The pyruvate dehydrogenase complex comes into play. b. Removal of a carbonyl group from pyruvate releases carbon dioxide. The pyruvate dehydrogenase complex comes into play. c. Removal of an acetyl group from pyruvate releases carbon dioxide. The pyruvate decarboxylase complex comes into play. d. Removal of an acetyl group from pyruvate releases carbon dioxide. The pyruvate dehydrogenase complex comes into play.

a

Energy can be taken in as glucose, and then has to be converted to a form that can be easily used to perform work in cells. What is the name of the latter molecule? a. Adenosine Triphosphate b.Electrolyte c. Cholesterol d. Anabolic molecule

a

Energy transfers take place constantly in everyday activities. Think of two scenarios: cooking on a stove and driving. How does the second law of thermodynamics apply to these scenarios? a. Heat is lost into the room while cooking and into the metal of the engine during gasoline combustion. b. Heat gained while cooking helps to make the food, and heat released due to gasoline combustion helps the car accelerate. c. The energy given to the system for cooking helps to make food, and energy in the car engine remains conserved when gasoline combustion takes place. d. The energy given to the system remains constant during cooking, and more energy isadded to the car engine when the gasoline combusts.

a

Enzymes facilitate chemical reactions that result in changes to a substrate. How does the induced-fit model of enzymes and substrates explain their function? a. Both enzymes and substrates undergo dynamic changes, inducing the transitions state of the substrate. b. The substrates attach to the enzyme, and the chemical reaction proceeds. c. The enzyme changes shape to fit the substrate, causing the transition state to occur. d. The enzyme induces a change in the substrate but is not changed itself during the reaction.

a

How does enzyme feedback inhibition benefit a cell? a. Feedback inhibition benefits the cell by blocking the production of the products by changing the configuration of enzymes. This will prevent the cells from becoming toxic. b. Feedback inhibition benefits the cell by blocking the production of the products by changing the configuration of reactants. This will prevent the cells from becoming toxic. c. Feedback inhibition benefits the cell by blocking the production of the reactants by changing the configuration of enzymes. This will prevent the cells from becoming toxic. d. Feedback inhibition benefits the cell by blocking the production of the products by reducing the reactants. This will prevent the cells from becoming toxic.

a

How is the energy from the sun transported within chloroplasts? a. When photons strike photosystem (PS) II, pigments pass the light energy tochlorophyll a molecules that excite an electron, which is then passed to the electrontransport chain. The cytochrome complex transfers protons across the thylakoidmembrane and transfers electrons from PS-II to PS-I. The products of the lightdependentreaction are used to power the Calvin cycle to produce glucose. b. When photons strike PS II, pigments pass the light energy to chlorophyll moleculesthat excite electrons, which are then passed to the electron transport chain. Thecytochrome complex transfers protons across the thylakoid membrane and transferselectrons from PS II to PS I. The products of the light-independent reaction are used topower the Calvin cycle to produce glucose. c. When photons strike PS II, pigments pass the light energy to chlorophyll moleculesthat in turn excite electrons, which are then passed to the electron transport chain.The cytochrome complex transfers protons across the thylakoid membrane andtransfers electrons from PS-I to PS-II. The products of the light-dependent reaction areused to power the Calvin cycle to produce glucose. d. When photons strike PS I, pigments pass the light energy to chlorophyll, moleculesthat excite electrons, which is then passed to the electron transport chain. Thecytochrome complex then transfers protons across the thylakoid membrane andtransfers electrons from PS-II to PS-I. The products of the light-dependent reaction areused to power the Calvin cycle to produce glucose.

a

If a chemical reaction could occur without an enzyme, why is it important to have one? a. Enzymes are important because they give the desired products only from the reaction. b. Enzymes are important because the products are obtained consistently with time. c. Enzymes are important because they do not disturb the concentration of the products. d. Enzymes are important because energy remains conserved and no loss of energy occurs.

a

In the following general reaction, how are electrons transferred? Explain the role of each species. Remember that R represents a hydrocarbon molecule and RH represents the same molecule with a particular hydrogen identified. RH + NAD+ → NADH + R a. NAD+, the oxidizing agent, donates its electrons to the reducing agent RH, forming R and NADH. b. NAD+, the reducing agent, accepts electrons from the oxidizing agent RH, producing NADH and R. c. RH acts as a reducing agent and donates its electrons to the oxidizing agent NAD+,forming NADH and R. d. RH acts as an oxidizing agent and donates electrons to the reducing agent NAD+,producing NADH and R.

a

Is the EA for ATP hydrolysis relatively low or high? Explain your reasoning. a. EA for ATP hydrolysis is high because considerable energy is released. b. EA for ATP hydrolysis is low because considerable energy is released. c. EA for ATP hydrolysis is high because a low amount of energy is released. d. EA for ATP hydrolysis is intermediate because considerable energy is released.

a

What evidence exists that the evolution of photosynthesis and cellular respiration support the concept that there is a common ancestry for all organisms? a. All organisms perform cellular respiration using oxygen and glucose, which areproduced by photosynthesis. b. All organisms perform cellular respiration using oxygen and lipids, which are producedby photosynthesis. c. All organisms perform cellular respiration using carbon dioxide and glucose, which areproduced by photosynthesis. d. All organisms perform cellular respiration using oxygen and lipids, which are producedby photosynthesis.

a

Which analogy best describes the induced-fit model of enzyme-substrate binding? a. One person's hand folds around another in a handshake b. A hug between two people c. The fitting together of two jigsaw puzzle pieces d. A square peg fitting through the square hole and a round peg fitting through the round hole of a children's toy

a

Which chemical reaction is more likely to occur? a. Exergonic b. Endergonic c. Endothermic d. Dehydration synthesis

a

How do chemical reactions play a role in energy transfer? a. Energy from the breakdown of glucose and other molecules in animals is released in the form of NADP, which transfers energy to other reactions. b. Energy from the breakdown of glucose and other molecules in animals is released as ATP, which transfers energy to other reactions. c. Energy is released in the form of water from the breakdown of glucose. These molecules transfer energy from one reaction to other. d. Energy is released in the form of glucose from the breakdown of ATP molecules. These ATP molecules transfer energy from one reaction to other.

b

How many NADH molecules are produced on each turn of the citric acid cycle? a. Two b. Three c. One d. Four

b

Metabolic pathways both produce and use energy to perform their reactions. How does the Calvin cycle help to harness, store, and use energy in its pathway? a. The Calvin cycle harnesses energy in the form of the 6 ATP and 6NADPH that are used to produce glyceraldehyse-3-phosphate (GA3P) molecules.These store the energy captured from photosynthesis. The cycle uses this energy toregenerate the RuBP that starts the cycle. b. The Calvin cycle harnesses energy in the form of 6 ATP and 6 NADPH that are used toproduce glyceraldehyde-3-phosphate (GA3P) molecules. These store the energycaptured from photosynthesis. The cycle uses this energy to regenerate RuBP. c. The Calvin cycle harnesses energy in the form of 3 ATP and 3 NADPH that are used toproduce glyceraldehyde-3-phosphate (GA3P) molecules. These store the energycaptured from photosynthesis. The cycle uses this energy to regenerate the RuBP. d. The Calvin cycle harnesses energy in the form of 6 ATP and 3 NADPH that are used toproduce glyceraldehyde-3-phosphate (GA3P) molecules. These store energy capturedfrom photosynthesis. The cycle uses this energy to regenerate RuBP.

b

Red blood cells (RBCs) do not perform aerobic respiration, but they do perform glycolysis. Why do all cells need an energy source, and what would happen if glycolysis were blocked in a red blood cell? a. Cells need energy to perform cell division. Blocking glycolysis in RBCs interrupts theprocess of mitosis, leading to nondisjunction b. Cells require energy to perform certain basic functions. Blocking glycolysis in RBCscauses imbalance in the membrane potential, leading to cell death. c. Cells require energy to recognize attacking pathogens. Blocked glycolysis inhibits theprocess of recognition, causing invasion of the RBCs by a pathogen d. Cells maintain the influx and efflux of organic substances using energy. Blockingglycolysis stops the binding of CO2 to the RBCs, causing cell death.

b

What food molecule used by animals for energy and obtained from plants is most directly related to the use of sun energy? a. triglyceride b. glucose c. protein d. tRNA

b

What happens if an enzyme is NOT functioning in a chemical reaction within a living organism that needs it? a. There is no change in the reaction rate. b. The reaction proceeds, but much more slowly. c. The reaction stops. d. The reaction proceeds faster without the interference.

b

What is the connection between anabolic and catabolic chemical reactions in a metabolic pathway? a. Catabolic reactions produce energy and simpler compounds, whereas anabolic reactions involve the use of energy to make more complex compounds. b. Catabolic reactions produce energy and complex compounds are formed, whereas in anabolic reactions, free energy is used by complex compounds to make simpler molecules. c. Catabolic reactions use energy and gives simpler compounds, whereas in anabolic reactions, energy is produced and simpler compounds are used to make complex molecules. d. Catabolic reactions produce energy and water molecules, whereas in anabolic reactions, this free energy is used by simpler compounds to make only proteins and nucleic acids.

b

What is the product of the Calvin cycle? a. Glyceraldehyde-3-phosphate b. Phosphoglycerate (PGA) c. Sucrose d. Glucose

b

What is the ultimate source of energy on this planet? a. Metabolic pathways b. The sun c. Plants d. Glucose

b

What type of reaction allows chemicals to be available for an organism's growth and maintenance in a timely manner? a. Redox reactions b. Enzymatically facilitated reactions c. Catabolic reactions d. Hydrolysis of ATP

b

Which molecules are oxidizing agents? a. FADH2 and NADH b. FAD+ and NAD+ c. FAD and FADH2 d. NAD+ and NADH

b

Which option describes the position of the transition state on a vertical energy scale, from low to high, relative to the position of the reactants and products, for both endergonic and exergonic reactions? a. The transition state of the reaction exists at a lower energy level than the reactants.Activation energy is always positive, regardless of whether the reaction is exergonic or endergonic. b. The transition state of the reaction exists at a higher energy level than the reactants.Activation energy is always positive, regardless of whether the reaction is exergonic or endergonic. c. The transition state of the reaction exists at an intermediate energy level than that of the reactants. Activation energy is always positive, regardless of whether the reaction is exergonic or endergonic. d. The transition state of the reaction exists at a lower energy level than the reactants.Activation energy is always negative, regardless of whether the reaction is exergonic or endergonic.

b

Which order of molecular conversions is correct for the Calvin cycle? a. CO2 → 3-PGA → RuBP → G3P b. RuBP + CO2 → [RuBisCO]3-PGA → G3P c. RuBP + G3P → 3-PGA → sugar d. RuBisCO → CO2 → RuBP → G3P

b

Which statement best describes how the citric acid cycle relates to glycolysis, oxidative phosphorylation, and chemiosmosis? a. Glycolysis produces pyruvate, which directly enters the citric acid cycle. This cycle produces the energy currency that undergoes the electron transport chain to produce water and ATP. b. Glycolysis produces pyruvate, which is converted to acetyl-CoA and enters the citric acid cycle. This cycle produces NADH and FADH2, which donate electrons to the electron transport chain to pump protons and produce ATP through chemiosmosis.Production of ATP using an electron transport chain and chemiosmosis is called oxidative phosphorylation. c. The citric acid produces pyruvate, which converts to glucose to enter glycolysis. This pathway produces NADH and FADH2, which enter oxidative phosphorylation to produce ATP through chemiosmosis. d. Citric acid produces NADH and FADH2, which undergo oxidative phosphorylation. This produces ATP by pumping protons through chemiosmosis. The ATP produced is utilized in large amounts in the process of glycolysis.

b

Consider a pendulum swinging. Which type(s) of energy is/are associated with the pendulum in the following instances? 1. The moment at which it completes one cycle, just before it begins to fall back toward the other end 2. The moment that it is in the middle between the two ends 3. Just before it reaches the end of one cycle, before step 1 a. 1. Potential and kinetic2. Kinetic3. Kinetic b. 1. Potential2. Potential and kinetic3. Potential and kinetic c. 1. Potential2. Kinetic3. Potential and kinetic d. 1. Potential and kinetic2. Potential and kinetic3. Kinetic

c

Enzyme inhibitors play an important part in the control of enzyme functions, allowing them to continue, or inhibiting them for a period of time. Which inhibitor affects the initial rate, but does NOT affect the maximal rate? a. Uncompetitive b. Noncompetitive c. Competitive d. Allosteric

c

Glucose catabolism pathways are sequential and lead to the production of energy. What is the correct order of the pathways for the breakdown of a molecule of glucose as shown in the formula? C6H12O6 + O2 → CO2 + H2O + energy a. Oxidative phosphorylation → citric acid cycle → oxidation of pyruvate → glycolysis b. Citric acid cycle → glycolysis → oxidative phosphorylation → oxidation of pyruvate c. Glycolysis → oxidation of pyruvate → citric acid cycle → oxidative phosphorylation d. The oxidation of pyruvate → citric acid cycle → glycolysis → oxidative phosphorylation

c

How many ATP molecules are used and produced per molecule of glucose during glycolysis? a. The first half of glycolysis produces 4 ATPs, and the second half of glycolysis uses2 ATPs. b. The first half of glycolysis produces 2 ATPs, and the second half of glycolysis uses4 ATPs. c. The first half of glycolysis uses 2 ATPs, and the second half of glycolysis produces4 ATPs. d. The first half of glycolysis uses 4 ATPs, and the second half of glycolysis produces2 ATPs.

c

If a plant were to be exposed to only red light, would photosynthesis be possible? a. The rate of photosynthesis would decrease drastically. b. Photosynthesis would not take place. c. The rate of photosynthesis would increase sharply. d. The rate of photosynthesis would decrease and then increase.

c

In which compartment of the plant cell do the light-independent ( Calvin Cycle) reactions of photosynthesis take place? a. Thylakoid b. Mesophyll c. Stroma d. Outer membrane

c

What are two major products of photosynthesis? a. Chlorophyll and oxygen b. Sugars/carbohydrates and carbon dioxide c. Sugars/carbohydrates and oxygen d. Oxygen and carbon dioxide

c

What best describes the effect of inputting energy into a living system? a. It causes enthalpy. b. The energy is used to produce carbohydrates. c. It decreases entropy within the system. d. It fuels catabolic reactions.

c

What can be calculated from a wavelength measurement of light? a. A specific portion of the visible spectrum b. The distance from trough to crest of the wave c. The amount of energy of a wave of light d. Color intensity

c

What cellular features and processes are similar in both photosynthesis and cellular respiration? a. Both processes are contained in organelles with single membranes, and neither uses aversion of the cytochrome complex. b. Both processes are contained in organelles with double membranes, and neither usesa version of the cytochrome complex. c. Both processes are contained in organelles with double membranes and use a versionof the cytochrome complex. d. Both processes are contained in organelles with single membranes, and both use aversion of the cytochrome complex.

c

What do the electrons added to NAD+ do in aerobic respiration? a. They are converted to NADP. b. They become part of a fermentation pathway. c. They go to another pathway for ATP production. d. They energize the acetyl group in the citric acid cycle.

c

What part of ATP is broken to release energy for use in chemical reactions? a. The bond between the first phosphate and the adenosine molecule b. The adenosine molecule c. The bond between the second and third phosphates d. The bond between the first and second phosphates

c

What will happen to a plant leaf that loses CO2 too quickly? a. Photosynthesis will decrease and then increase. b. Photosynthesis will increase exponentially. c. Photosynthesis will slow down or possibly stop. d. There will be no effect on the rate of photosynthesis.

c

What would be the outcome if hydrogen ions were able to diffuse through the mitochondrial membrane into the mitochondria without the need for integral membrane proteins? a. Pyruvate would not be produced. b. Carbon dioxide would not be produced c. ATP would not be produced. d. Citric acid would not be produced

c

Where do the electrons moving along the membrane in the figure come from, and where do the electrons end up? a. The electrons are emitted by ubiquinone and are, in turn, transferred from complex Ito complex II. Water finally accepts the electrons. b. The electrons are given off by water and finally accepted by NAD+ and FAD+ to produce the energy currencies NADH and FADH2. c. The electrons are released by NADH and FADH2 and finally accepted by oxygen to form water. d. The electrons are given out by NADH and FADH2 and are, in turn, finally accepted byH2O.

c

Which component is NOT used by both plants and cyanobacteria to carry out photosynthesis? a. water b. Carbon dioxide c. Chloroplasts d. chlorophyll

c

Which molecules are produced in glycolysis and used in fermentation? a. Lactate, ATP, and CO2 b. Glucose, ATP, and NAD+ c. Pyruvate and NADH d. Acetyl-CoA and NADH

c

Which substance catalyzes (enzyme) carbon fixation? a. 3-PGA b. RuBP c. RuBisCO d. NADPH

c