biology learning curve

During photosynthesis in plants and algae, __________ is oxidized and __________ is reduced. CO2; H2O O2; CO2 H2O; CO2 NADPH; ATP H2O; O2

H2O; CO2

During photosynthesis in plants and algae, __________ is oxidized and __________ is reduced. O2; CO2 H2O; CO2 CO2; H2O H2O; O2 NADPH; ATP

H2O; CO2

In plants and algae, which of the following is a by-product of photosynthesis? O2 CO2 H2O C6H12O6 H+

o2

Which of the following is a product of the breakdown of lipids? Select all correct choices. glycerol NADH FADH2 Acetyl-CoA

glycerol NADH FADH2 Acetyl-CoA

The citric acid cycle is a cycle because the starting molecule, _____, is regenerated at the end. acetyl-CoA fructose 6-diphosphate pyruvate oxaloacetate citrate

oxaloacetate

How many cells are there on Day 3 in the culture that contains serum? 80,000 800,000 40,000 400,000

800,000

Excess glucose is stored in large branched molecules of: glycogen in animals. starch in bacteria. starch in animals. glycogen in plants. glycogen and starch in both animals and plants.

glycogen in animals.

At what point are there approximately seven times more cells in one treatment than in the other? Day 2 Day 3 Day 4 Day 1

Day 2

To see if a growth-promoting factor was released from blood platelets, cells called fibroblasts were placed in a dish containing liquid cell culture medium. The medium was supplemented with either serum (collected from blood that had been allowed to clot) or plasma from blood in which the platelets had not been activated during the clotting process. The number of cells in each culture is shown in the graph. At what point are there approximately four times more cells in one treatment than the other? Day 2 Day 4 Day 1 Day 3

Day 3

Chemicals called un-couplers can make membranes permeable to small molecules and ions. What effect might un-couplers have on photosynthesis? Decreased ATP production because the proton-gradient would increase Increased ATP production because cyclic electron transport would increase Decreased ATP production because the proton-gradient would decrease Decreased NADPH production because the proton-gradient would increase Decreased NADPH production because the proton-gradient would decrease

Decreased ATP production because the proton-gradient would decrease

In the developing nervous system, ________ is the signaling molecule that results in the differentiation of ___________. Notch; glial cells Notch; neurons Delta; glial cells Delta; neurons

Delta; glial cells

How does the metabolism occurring in chloroplasts differ from that of mitochondria? Different proton sources Different electron sources Different electron acceptors Different electron acceptors and sources None of these answer options is correct.

Different electron acceptors and sources

Lactic acid and ethanol fermentation differ in that: FADH2 is oxidized to FADH in lactic acid fermentation, but NADH is oxidized to NAD+ in ethanol fermentation. NADH is oxidized to NAD+ in lactic acid fermentation, but FADH2 is oxidized to FADH in ethanol fermentation. lactic acid fermentation produces ATP by substrate level phosphorylation, but ethanol fermentation does not. Ethanol fermentation produces CO2, but lactic acid fermentation does not. ethanol fermentation produces ATP by substrate level phosphorylation, but lactic acid fermentation does not.

Ethanol fermentation produces CO2, but lactic acid fermentation does not.

Which of the following does not occur during the third phase of glycolysis? pyruvate production ATP synthesis None of the answer options is correct. the transfer of high-energy electrons to NAD+ oxygen consumption

oxygen consumption

Which of the following does not occur during the third phase of glycolysis? pyruvate production ATP synthesis oxygen consumption the transfer of high-energy electrons to NAD+ None of the answer options is correct.

oxygen consumption

Platelet-derived growth factor (PDGF) is a signaling molecule that functions in which of the following types of cell signaling? juxtacrine All of these choices are correct. paracrine endocrine autocrine

paracrine

Which type of signaling is blocked by the toxin, curare? juxtacrine autocrine endocrine paracrine

paracrine

Growth factors such as platelet-derived growth factor function in: autocrine signaling. paracrine signaling. endocrine signaling. juxtacrine signaling.

paracrine signaling.

Growth factors such as platelet-derived growth factor function in: paracrine signaling. endocrine signaling. juxtacrine signaling. autocrine signaling.

paracrine signaling.

In the Calvin cycle, ATP is required to __________. phosphorylate 3-PGA reduce 3-PGA reduce triose phosphates reduce RuBP carboxylate RuBP

phosphorylate 3-PGA

In the Calvin cycle, ATP is required to __________. reduce triose phosphates phosphorylate 3-PGA reduce RuBP reduce 3-PGA carboxylate RuBP

phosphorylate 3-PGA

The ability of a specific tissue or organ to respond to the presence of a hormone is dependent on: the location of the tissue or organ with respect to the circulatory path. nothing - all hormones of the body are able to stimulate all cell types because hormones are powerful and nonspecific. the presence of the appropriate receptors on the cells of the target tissue or organ. the membrane potential of the cells of the target organ.

. the presence of the appropriate receptors on the cells of the target tissue or organ.

For every turn of the Calvin cycle, how many triose phosphates are exported from the chloroplast? 1 3 5 6 12

1

Which of the following is a net product of the citric acid cycle for each molecule of pyruvate generated in glycolysis? Select all correct choices. 1 ATP 3 NADH 1 FADH2

1 ATP 3 NADH 1 FADH2

The biosynthetic pathway for chlorophyll includes approximately how many steps? 3 6 10 17 40

17

A single molecule of glucose requires _____ "turns" through the citric acid cycle for its chemical energy to be completely harvested. 2 3 1 5 4

2

For every six CO2 molecules fixed, how many triose phosphates are exported from the chloroplast? 12 10 2 6 1

2

How many reactions in glycolysis directly generate ATP? 1 2 3 4 5

2

Nicotine from cigarette smoke acts as a ligand and associates with specific proteins on the surface cells in the brain, causing feelings of pleasure and well-being. Below are the events that happen in the cellular response to nicotine. Place the events in the correct order to describe the five basic steps in the pathway of a signal transduction system. 1. receptor binding 2. receptor activation 3. signal transduction 4. response 5. termination The opening of an ion channel as a result of nicotine association is an example of ____________. ____________ occurs when an influx of ions causes an action potential, which carries the signal to the reward areas of the brain. Nicotine interaction with the transmembrane protein that normally binds the neurotransmitter acetylcholine is an example of ____________. ____________ occurs when the signal causes release of dopamine in the brain, which causes relaxation and feelings of well-being. Rapid elimination of nicotine from the body is an example of ____________. 5, 2, 3, 1, 4 3, 1, 5, 2, 4 2, 3, 1, 4, 5 4, 2, 1, 5, 3

2, 3, 1, 4, 5

A photosynthetic electron-transport chain harnesses approximately what percentage of the sun's usable energy arriving at the surface of a leaf? 8% 12% 24% 60% 95%

24%

The approximate yield of ATP from the full oxidation of a molecule of glucose is: 2 6 12 32 64

32

After acetyl-CoA synthesis, the chemical energy of how many carbons of the original glucose molecule will be converted to chemical energy in the form of ATP in the remaining steps of aerobic respiration? 2 1 3 5 4

4

Approximately what percentage of the sun's output is available for photosynthesis? 4% 8% 20% 40% 60%

40 %

Which of the following is at the highest energy level? A reaction center chlorophyll that has received the energy from a blue-light photon A reaction center chlorophyll that has received the energy from a red-light photon A reaction center chlorophyll that has received the energy from a green-light photon

A reaction center chlorophyll that has received the energy from a blue-light photon

Which best describes energy production during cellular respiration? A small amount of energy is produced by substrate level phosphorylation; most is produced by oxidative phosphorylation. A small amount of energy is produced by oxidative phosphorylation; most is produced by substrate level phosphorylation. An equal amount is produced by oxidative and substrate level phosphorylation. It depends on the organism. Some produce most of their energy by substrate level phosphorylation, and some produce most of their energy by oxidative phosphorylation. None of these answer options accurately describes energy production during cellular respiration.

A small amount of energy is produced by substrate level phosphorylation; most is produced by oxidative phosphorylation.

Which best describes energy production during cellular respiration? A small amount of energy is produced by substrate level phosphorylation; most is produced by oxidative phosphorylation. A small amount of energy is produced by oxidative phosphorylation; most is produced by substrate level phosphorylation. An equal amount is produced by oxidative and substrate level phosphorylation. It depends on the organism. Some produce most of their energy by substrate level phosphorylation, and some produce most of their energy by oxidative phosphorylation. None of these answer options accurately describes energy production during cellular respiration.

A small amount of energy is produced by substrate level phosphorylation; most is produced by oxidative phosphorylation.

Which of the following is needed directly to produce both triose phosphates and RuBP? ATP NADPH Rubisco PSII O2

ATP

Which of the following is needed directly to produce both triose phosphates and RuBP? NADPH Rubisco ATP PSII O2

ATP

CO2 reduction requires __________. ATP ATP and NADPH NADPH RuBP Rubisco

ATP and NADPH

CO2 reduction requires __________. RuBP ATP ATP and NADPH Rubisco NADPH

ATP and NADPH

During the citric acid cycle: ATP is synthesized by oxidative phosphorylation. ATP is synthesized by substrate level phosphorylation. fuel molecules are completely reduced. high-energy electrons are removed from NAD+ and FADH.

ATP is synthesized by substrate level phosphorylation.

For the potential energy of a proton gradient to be converted to the chemical energy of ATP, the movement of protons down their electrochemical gradient must be coupled with ATP synthesis. This coupling is made possible by: coenzyme Q. ATP synthase. cytochrome C. protein complex IV. oxygen.

ATP synthase

Which of the following statements is true regarding acetyl-CoA synthesis? Acetyl-CoA synthesis ends with the oxidation of an acetyl group, which forms CO2. Like glycolysis, acetyl-CoA synthesis is carried out in the mitochondria. Acetyl-CoA synthesis forms the same number of NADH (per glucose molecule) as glycolysis. Acetyl-CoA synthesis directly follows the citric acid cycle during cellular respiration.

Acetyl-CoA synthesis forms the same number of NADH (per glucose molecule) as glycolysis.

Which of the following statements is true regarding acetyl-CoA synthesis? Acetyl-CoA synthesis forms the same number of NADH (per glucose molecule) as glycolysis. Acetyl-CoA synthesis ends with the oxidation of an acetyl group, which forms CO2. Like glycolysis, acetyl-CoA synthesis is carried out in the mitochondria. Acetyl-CoA synthesis directly follows the citric acid cycle during cellular respiration.

Acetyl-CoA synthesis forms the same number of NADH (per glucose molecule) as glycolysis.

Xanthophyll pigments __________. prevent formation of reactive oxygen species absorb light energy convert light energy into heat reflect yellow light All answer options are correct.

All answer options are correct.

Which one of the following complexes does not actively move protons from the mitochondrial matrix to the intermembrane space? Complex I Complex II Complex III Complex IV All four complexes actively move protons from the mitochondrial matrix to the intermembrane space.

Complex II

Recall that cyanobacteria may have developed as a result of horizontal gene transfer: a bacterium carrying the genetic information for one photosystem received (from another bacterium) the genetic information for a second, distinct photosystem. What might be possible mechanisms of action for horizontal gene transfer? Bacteria could take up genetic information (released from dead bacteria) from their surroundings. Bacteria may exchange genetic information through the development of cytoplasmic connections. Bacteria may become infected by a virus that carries genetic information taken from previously infected bacteria. All of the answer options are correct.

All of the answer options are correct.

The pyruvate dehydrogenase complex plays a role in which of the following processes? the formation of NADH the oxidation of pyruvate the formation of acetyl-CoA the formation of CO2 All of the answer options are correct.

All of the answer options are correct.

Which of the following statements are true regarding acetyl-CoA synthesis? This process occurs within the matrix of mitochondria. This process constitutes the second stage of cellular respiration. The process produces both CO2 and acetyl-CoA. The process yields no ATP via substrate-level phosphorylation. All of the answer options are correct.

All of the answer options are correct.

Which of the following statements is true regarding reactive oxygen species? Reactive oxygen species are formed when excess electrons are added to O2. Reactive oxygen species are likely to form if NADP+ is rare in a cell. Reactive oxygen species can form when O2 is exposed to excess light energy. Reactive oxygen species can be "neutralized" by antioxidants. All of the answer options are correct.

All of the answer options are correct.

Ligand binding to a receptor kinase results in: phosphorylation of the cytoplasmic domain of the receptor. binding of cytoplasmic signaling molecules. receptor dimerization. All of these answer options are correct.

All of these answer options are correct.

What happens to the alpha subunit of a G protein with GDP attached? It re-assembles with the beta and gamma subunits. It no longer activates an effector protein. It re-associates with the G protein-coupled receptor. All of these answer options are correct.

All of these answer options are correct.

What is a growth factor? a small protein that influences cell growth and division a signaling molecule involved in paracrine signaling a soluble molecule that can alter gene expression in a cell All of these answer options are correct.

All of these answer options are correct.

Which of the following is a cellular response to signal transduction? a change in the proteins found in the cytosol the release of more signal molecules a change in the activity of an enzyme All of these answer options are correct.

All of these answer options are correct.

According to Fig 9.10, which of the following is NOT responsible for amplifying the signal in a cell responding to adrenaline signaling? the binding of the receptor by adrenaline All of these choices amplify the adrenaline signal. the production of cAMP by adenylyl cyclase the phosphorylation of proteins by protein kinase A the activation of protein kinase A by cAMP

All of these choices amplify the adrenaline signal.

A G protein: is a component of a signal-transduction pathway that is coupled to a G protein-coupled receptor. becomes deactivated when bound GTP is dephosphorylated to GDP. All of these choices are correct. is composed of three subunits and is inactive when bound to GDP. releases GDP and binds to GTP when associated with an activated receptor.

All of these choices are correct.

A researcher is studying a G protein-coupled receptor in eukaryotic cells. In one group of cells, he notices that even though a ligand can bind to its G protein-coupled receptor, nothing happens. Why could this happen? The G protein-coupled receptor may fail to undergo a conformational change upon the binding of its ligand. These cells might carry a mutation that affects the transmembrane portion of the G protein-coupled receptor. These cells might carry mutations in the downstream signaling pathway associated with this ligand/G protein-coupled receptor. All of these choices are correct.

All of these choices are correct.

The Delta protein: All of these choices are correct. arises in embryonic stem cells as they differentiate into neurons in the brain. directs adjacent cells to differentiate into glial cells. is a transmembrane protein found in embryonic brain cells. directly signals to a Notch transmembrane protein in adjacent cells.

All of these choices are correct.

A researcher is evaluating the role of a growth factor during embryonic development. He notices that this factor functions in both neural development and limb development. How is that possible? The effects of the growth factor may be concentration-dependent. The effects of the growth factor may be dependent on location. The growth factor may result in the transcription of different genes depending on its location. The growth factor may be signaling through different transduction pathways. All of these choices are possible explanations for the observations.

All of these choices are possible explanations for the observations.

Assuming that all is working properly, which of the following is at a higher energy level? An excited-state antenna chlorophyll An excited-state reaction center chlorophyll

An excited-state antenna chlorophyll

Which of the following are Rubisco substrates? CO2 and RuBP O2 RuBP CO2, O2, and RuBP CO2

CO2, O2, and RuBP

Which of the following are Rubisco substrates? CO2 and RuBP RuBP O2 CO2 CO2, O2, and RuBP

CO2, O2, and RuBP

Which of the following are Rubisco substrates? O2 CO2 CO2 and RuBP CO2, O2, and RuBP RuBP

CO2, O2, and RuBP

Many pathologies are the result of a problem with cell signaling. Which of the following pathologies best exemplifies this fact? Cancer, caused by a truncated receptor that is now stuck in the activated form. Cystic fibrosis, where there is a mutation in a channel protein, resulting in a buildup of mucus. Familial hypercholesterolemia (high cholesterol in the blood), caused by a decrease in the number of receptors for cholesterol. Congestive heart failure, caused by chronic high blood pressure due to excessive sodium intake.

Cancer, caused by a truncated receptor that is now stuck in the activated form.

According to Fig. 9.6, what is a key difference between cell signaling mediated by a surface receptor, compared to that mediated by an intracellular receptor? None of these statements about cell signaling differences is correct. Signaling molecules that bind to cell-surface receptors lead to cellular responses restricted to the cytoplasm; signaling molecules that bind to intracellular receptors lead to cellular responses restricted to the nucleus. Cell-surface receptors bind polar signaling molecules; intracellular receptors bind nonpolar signaling molecules. Cell-surface receptors bind to specific signaling molecules; intracellular receptors bind any signaling molecule. Cell-surface receptors typically bind to smaller signaling molecules than those bound by intracellular receptors.

Cell-surface receptors bind polar signaling molecules; intracellular receptors bind nonpolar signaling molecules.

Many scientists use chemical inhibitors to interfere with normal signaling pathways within eukaryotic cells. If such inhibitors are large, nonpolar molecules, what is the likely method of action of these chemical inhibitors? Chemical inhibitors likely enter eukaryotic cells and interfere with components of the signal transduction pathway. Chemical inhibitors likely enter the nucleus and prevent the transcription of the pathway of interest's target genes. Chemical inhibitors likely bind to receptors and interfere with receptor activation or signal-receptor binding. Chemical inhibitors likely interfere with the termination of signaling, so eukaryotic cells can't process new signals.

Chemical inhibitors likely bind to receptors and interfere with receptor activation or signal-receptor binding.

Which one of the following is believed to have served as the first electron donor? Mg2+ 18O2 Fe2+ NADPH 35S

Fe2+

Imagine that a eukaryotic cell carries a mutation impairing its ability to phosphorylate glucose during glycolysis. What is a likely result of this mutation? High (possibly toxic) levels of glucose would accumulate in the cell. Glucose could move out of the cell, slowing cellular respiration. Because phosphorylation stabilizes glucose, glucose would spontaneously form pyruvate. Without the phosphorylation of glucose, glycolysis would consist entirely of exergonic reactions. More pyruvate would be formed at the end of glycolysis

Glucose could move out of the cell, slowing cellular respiration.

During their experiments with chlorella, Calvin and Benson found no free glucose. Why do you think this is? Glucose takes too long to synthesize. Glucose would cause H2O to leave the Chlorella cells. Glucose is an isomer of fructose. Glucose is stored as starch. Green algae do not respire when illuminated.

Glucose is stored as starch.

______________ is found in animals, and possesses a large, central protein. ____________ is found in plants, and lacks a central protein. Starch; Starch also Glycogen; Starch Glycogen; Glycogen also Starch; Glycogen

Glycogen; starch

PSII and PSI differ in __________. H+ production H+ production and electron donors electron donors and acceptors H+ production, and electron donors and acceptors plants and algae

H+ production, and electron donors and acceptors

In plants and algae, __________ is the source of the electrons needed for photosynthesis. H2O H+ O2 CO2 NADPH

H20

In plants and algae, __________ is the source of the electrons needed for photosynthesis. H2O NADPH CO2 O2 H+

H2O

In plants and algae, __________ is the source of the electrons needed for photosynthesis. O2 NADPH CO2 H+ H2O

H2O

What does a ligand-gated channel do? It activates a G protein. It binds small, nonpolar signaling molecules. It triggers the activity of a phosphatase. It allows for the movement of ions across the plasma membrane.

It allows for the movement of ions across the plasma membrane.

Some present-day bacteria use a system of anaerobic respiration characterized by an electron transport chain analogous to that found in aerobic organisms. Which of the following correctly characterizes the anaerobic electron transport chain? It uses oxygen as a final electron acceptor. It is embedded in the outer mitochondrial membrane rather than the inner mitochondrial membrane. It establishes a proton gradient between the cytoplasm and the extracellular fluid. It establishes a proton gradient between the intermembrane space and the cytoplasm. None of these answer options accurately characterizes the anaerobic electron transport chain.

It establishes a proton gradient between the cytoplasm and the extracellular fluid.

What happens to pyruvate during the process of fermentation? It is oxidized to ethanol. It is reduced to ethanol. It is converted to acetyl Co-A. It is oxidized to lactic acid. It gets converted to pyruvic acid.

It is reduced to ethanol.

Which of the following statements is true regarding a reducing agent? It loses electrons. It gains electrons. It is usually oxygen. It is an electron acceptor. It is never oxidized.

It loses electrons.

In cell communication, which one of the following is a requirement of the responding cell? It must be a prokaryotic cell. It must have receptor proteins. It must be a eukaryotic cell. It must produce signaling molecules.

It must have receptor proteins.

If oxygen is unavailable, predict what happens to the citric acid cycle. It stops because the supplies of NAD+ and FAD become depleted. It stops because ADP levels increase in the absence of oxygen. It continues because none of the reactions in the citric acid cycle require oxygen. It continues because ATP levels are low, and low ATP activates enzymes of the cycle.

It stops because the supplies of NAD+ and FAD become depleted.

Which of the following best describes how ATP synthase converts the potential energy of the proton gradient to the chemical energy of ATP? Do protons flow through the F0 or F1? Kinetic energy from the flow of protons is converted to the kinetic energy of rotation of the Fo subunit; the rotation of the Fo subunit leads to rotation of the F1 subunit, which can then catalyze ATP synthesis. The flow of protons through the F0 subunit reduces the F1 subunit, which allows ADP to be oxidized to ATP. The flow of protons through the F0 subunit oxidizes the F1 subunit, which allows ADP to be reduced to ATP. Kinetic energy from the flow of protons is stored in a new electrochemical gradient within the F0 subunit. The potential energy of the electrochemical gradient, in turn, is converted to kinetic energy in the F1 subunit and used to catalyze ATP synthesis. None of these answer options accurately describes how ATP synthase converts the potential energy of the proton gradient to the chemical energy of ATP.

Kinetic energy from the flow of protons is converted to the kinetic energy of rotation of the Fo subunit; the rotation of the Fo subunit leads to rotation of the F1 subunit, which can then catalyze ATP synthesis.

Which of the following statements is not true regarding a neurotransmitter? Like Delta or Notch, neurotransmitters are usually attached to the cell surface. Neurotransmitters play a role in muscle contraction. Neurotransmitters are typically dispersed over small distances. Neurotransmitters are examples of growth factors. Neurotransmitters are produced by neurons.

Like Delta or Notch, neurotransmitters are usually attached to the cell surface.

Review the experiments by Kohler and Lipton described in Fig. 9.5. What is the key difference between blood serum and blood plasma that affects their ability to help fibroblasts grow in culture? Serum contains more platelet cells than plasma, and platelet cells promote cell growth. Plasma contains more platelet cells than serum, and platelet cells inhibit cell growth. Molecules found in plasma inhibit cell growth; these molecules are not found in serum. Molecules found in serum promote cell growth; these molecules are not found in plasma.

Molecules found in serum promote cell growth; these molecules are not found in plasma.

When a single pyruvate is converted to acetyl-CoA, the other products of the reaction are: CO2 and ATP. Pi and FADH2. ATP and NADH. NADH and CO2. FADH2 and ATP.

NADH and CO2.

The inputs to glycolysis do not include (select all correct choices): NAD+. ADP. glucose. NADH. Pi.

NADH.

In addition to chlorophylls, light-harvesting antennae include other pigments. What is the benefit of these additional pigments? Increased structural stability of the antenna Lower anti-oxidant capacity Enhanced resonance transfer Narrower range of wavelength reflection Tighter binding of the antennae to the thylakoid

Narrower range of wavelength reflection

n addition to chlorophylls, light-harvesting antennae include other pigments. What is the benefit of these additional pigments? Lower anti-oxidant capacity Increased structural stability of the antenna Tighter binding of the antennae to the thylakoid Enhanced resonance transfer Narrower range of wavelength reflection

Narrower range of wavelength reflection

In the lab you isolate a chlorella mutant that is unable to switch xanthophyll pigments into the inactive, non-heat-dissipating form. If you released that mutant into a small pond shaded by trees, would the mutation spread, and why? Yes, the heat released by the xanthophylls would warm up the cells and enhance photosynthesis. No, light absorbed by xanthophylls is not used to make ATP or NADPH. No, the xanthophylls prevent the production of reactive oxygen species. Yes, the xanthophylls prevent the production of reactive oxygen species. No, mutations never spread in nature.

No, light absorbed by xanthophylls is not used to make ATP or NADPH.

How many mol NADPH are required for 12 mol RuBP to be carboxylated by rubisco? 10 12 24 36 None of the answer options is correct.

None of the answer options is correct.

Notch and Delta are both transmembrane proteins involved in cell communication in the developing nervous system of vertebrate animals. What makes Notch different from Delta? Notch is a receptor and Delta is a signaling molecule. Notch is a signaling molecule and Delta is a receptor. Notch is required at higher density than Delta to alter cell fate. All of the above statements are correct.

Notch is a receptor and Delta is a signaling molecule.

In plants and algae, which of the following is a by-product of photosynthesis? CO2 H+ H2O O2 C6H12O6

O2

Which one of the following would least likely be found in the outer regions of the granal stacks? Photosystem I Photosystem II ATP synthase Cytochrome b6f complex All of these choices are equally likely to be found in the outer regions of the granal stacks.

Photosystem II

Which of the following compounds is consumed by carboxylation? RuBP ATP NADPH 3-PGA ATP and NADPH

RuBP

Which of the following compounds is consumed by carboxylation? RuBP NADPH ATP 3-PGA ATP and NADPH

RuBP

The Calvin cycle includes 15 enzymes, most of which are involved in __________. RuBP carboxylation RuBP regeneration ATP synthesis reduction starch synthesis

RuBP regeneration

The Calvin cycle includes 15 enzymes, most of which are involved in __________. RuBP carboxylation starch synthesis reduction RuBP regeneration ATP synthesis

RuBP regeneration

The Calvin cycle includes 15 enzymes, most of which are involved in __________. starch synthesis RuBP carboxylation RuBP regeneration reduction ATP synthesis

RuBP regeneration

The regeneration of RuBP typically limits the rate of photosynthesis under low light intensities. This is because __________. RuBP regeneration requires ADP RuBP regeneration requires ATP RuBP regeneration is part of the "dark reactions" photosynthesis occurs only in high light None of the answer options is correct.

RuBP regeneration requires ATP

Review the experiment illustrated in Figure 8.7. Based on the result of Experiment #2 and on what you know about photosynthesis, which of the 2-D paper chromatography patterns below would be observed if the cells treated with 14C had been allowed to remain in culture for a longer period of time before they were put in the boiling alcohol?

RuBp Triose phosphates

What happens when a ligand binds to a ligand-gated Na+ channel? There is no net flow of sodium ions. Sodium ions flow passively from high concentration to low concentration. Sodium ions flow passively from low concentration to high concentration. Sodium ions are pumped from low concentration to high concentration.

Sodium ions flow passively from high concentration to low concentration.

Why don't steroid hormones bind to transmembrane cell-surface receptors? Steroid hormones are not signaling molecules. Steroid hormones don't require receptors because they bind directly to the cell's DNA. Steroid hormones are nonpolar and will cross the cell's plasma membrane, binding to receptors inside the cell. Steroid hormones are nonpolar and therefore cannot bind to receptors.

Steroid hormones are nonpolar and will cross the cell's plasma membrane, binding to receptors inside the cell.

In 1937, two German biochemists published a paper proposing the following reactions as part of the glucose oxidation: citrate → isocitrate → α-ketoglutarate → succinate → fumarate → malate → oxaloacetate Adding succinate, fumarate, or malate to thin slices of tissue increased oxygen consumption, supporting the hypothesis that these molecules are intermediates in the process. However, a puzzling observation was that intermediates were still present in the reaction mixture at the end of the experiment. If they are intermediates, then they should be consumed as the next product in the pathway is formed. What explains this observation? Succinate, fumarate, and malate are not reactants but catalysts, and catalysts are not consumed in the process. Succinate, fumarate, and malate are constantly regenerated in the citric acid pathway. Succinate, fumarate, and malate increase metabolism and therefore oxygen consumption, but they are not directly part of the glucose oxidation pathway.

Succinate, fumarate, and malate are constantly regenerated in the citric acid pathway.

We consume a variety of carbohydrates that are digested into a variety of different sugars. How do these different sugars enter glycolysis? All sugars are converted to fructose 6-phosphate and enter glycolysis at phase 1, step 3. All sugars are converted to glyceraldehyde 3-phosphate and enter glycolysis at phase 3, step 6. All sugars are converted to glucose 6-phosphate and enter glycolysis at phase 1, step 2. Sugars are converted to various forms and enter glycolysis at various stages. None of the answer options is correct.

Sugars are converted to various forms and enter glycolysis at various stages.

During the signal transduction process, the signal often goes through a cascade. For example: Activated receptor continually activates hundreds of protein A. Each activated protein A will activate hundreds of protein B, and so on until we get to the cellular response. What purpose does this cascade serve? The cascade seen in signal transduction makes it easier to shut off or terminate. Having several intermediates allows for greater control of the response. Having a cascade allows the cell to respond to different signals. The cascade serves to amplify the signal, so one activated receptor can have a significant response.

The cascade serves to amplify the signal, so one activated receptor can have a significant response.

During the signal transduction process, the signal often goes through a cascade. For example: Activated receptor continually activates hundreds of protein A. Each activated protein A will activate hundreds of protein B, and so on until we get to the cellular response. What purpose does this cascade serve? The cascade serves to amplify the signal, so one activated receptor can have a significant response. The cascade seen in signal transduction makes it easier to shut off or terminate. Having several intermediates allows for greater control of the response. Having a cascade allows the cell to respond to different signals.

The cascade serves to amplify the signal, so one activated receptor can have a significant response.

Imagine that you notice rust has formed on the frame of your bicycle. How would this have happened? The iron in your bicycle frame was oxidized and gained electrons. The iron in your bicycle frame was reduced and lost electrons. The iron in your bicycle frame was reduced and gained electrons. The iron in your bicycle frame was oxidized and lost electrons.

The iron in your bicycle frame was oxidized and lost electrons.

Imagine that a researcher is studying the embryonic development of mice that do not express Delta. What will likely be true of these mice? These mice will have fewer neurons compared to their normal counterparts. The mice will have fewer glia compared to their normal counterparts. The mice will have fewer neurons and more glia compared to their normal counterparts. These mice will have more neurons compared to their normal counterparts. These mice will have more glia compared to their normal counterparts.

The mice will have fewer glia compared to their normal counterparts.

Which of the following statements is true regarding the earliest photosynthetic organisms on Earth? These organisms likely possessed dual photosystems. Given the abundance of H2O on early Earth, these organisms used H2O as an electron donor. The organisms likely used inorganic molecules (i.e., H2S) as electron donors. The organisms likely produced oxygen as a waste product, resulting in Earth's current atmosphere. These organisms likely used both inorganic molecules and water as electron donors.

The organisms likely used inorganic molecules (i.e., H2S) as electron donors.

Which of the following statements is true regarding the equation C6H12O6 + 6O2 →6CO2+ 6H2O + energy? The oxygen atoms in both CO2 and H2O are electronegative. The movement of hydrogen atoms in reactions involving C6H12O6 and H2O yields no information regarding the movement of electrons. In CO2, the oxygen atoms lose electrons and the carbon atom is oxidized. Glucose could be considered a reducing agent. The oxygen atoms in both CO2 and H2O are electronegative, and glucose could be considered a reducing agent.

The oxygen atoms in both CO2 and H2O are electronegative, and glucose could be considered a reducing agent.

A researcher is carrying out an experiment where she labels a protein with a fluorescent tag (so she can visualize its location in a cell), and introduces this tagged protein into the lumen of a single thylakoid. She observes her treated cells periodically, and notices that the labeled protein can move between grana, but is never observed in the stroma. What can she deduce? All thylakoid membranes and grana share a common lumen, through which the labeled protein can move. This protein likely travels between different thylakoid membranes by moving through the stroma, but its movement through the stroma is very brief. This protein can easily transfer between the inner and outer mitochondria membranes. This protein cannot easily diffuse through the thylakoid membrane. The protein likely travels through a common lumen shared by thylakoid membranes and grana, and cannot easily diffuse through the thylakoid membrane.

The protein likely travels through a common lumen shared by thylakoid membranes and grana, and cannot easily diffuse through the thylakoid membrane.

Why do the functions of many receptor kinases depend on the fluid nature of the plasma membrane? The receptor monomers must move together and dimerize to be activated. The generation of cAMP requires a fluid membrane. Binding of ligand to the receptor requires a fluid membrane. Phosphorylation requires a fluid membrane.

The receptor monomers must move together and dimerize to be activated.

A researcher introduces a signal produced by bacteria to eukaryotic cells he is culturing in the laboratory. Remarkably, he notices that this signal results in an increase in eukaryotic gene expression. How is this possible? This signal is likely similar in structure to ligands utilized by eukaryotic cells. This prokaryotic signal likely travels directly into eukaryotic cells and acts as a transcription factor. This signaling pathway might actually be utilized by both prokaryotes and eukaryotes. This gene expression is likely independent of the presence of the prokaryotic signal. The signal is either similar in structure to a ligand used by eukaryotes, or this signaling pathway is utilized by both prokaryotes and eukaryotes.

The signal is either similar in structure to a ligand used by eukaryotes, or this signaling pathway is utilized by both prokaryotes and eukaryotes.

The coronary arteries supply blood to the heart muscles. Which of the following events would occur in heart tissue following a heart attack due to a block in the coronary arteries? Choose all correct answers. There would be an accumulation of lactic acid in the tissue due to glycolysis and fermentation. There would be a decrease in the production of ATP. There would be a stimulation of phosphofructokinase, an intermediary enzyme of glycolysis. There would be an increase in the production of water.

There would be an accumulation of lactic acid in the tissue due to glycolysis and fermentation. There would be a decrease in the production of ATP. There would be a stimulation of phosphofructokinase, an intermediary enzyme of glycolysis.

Sonic hedgehog is an example of: a hormone. a growth factor. a paracrine signal. a juxtacrine signal. both a growth factor and paracrine signal.

both a growth factor and paracrine signal.

Recall from the text the example of cell communication in Streptococcus pneumoniae: the rate of DNA uptake by pneumococcal cells increases sharply when they are at high density due to changes in gene expression brought about by signaling between cells. If the pneumococcal cells did not express receptor protein, how would the rate of DNA uptake be affected when the cells reach high density? There would be no change in the rate of DNA uptake. There would be a larger than normal increase in the rate of DNA uptake. There would be a smaller than normal increase in the rate of DNA uptake. There would be a decrease in the rate of DNA uptake.

There would be no change in the rate of DNA uptake.

Which of the following statements is true regarding Earth's earliest organisms? These organisms likely used oxygen as an electron acceptor. These organisms carried out fermentation because early Earth was oxygen-poor. Some of these organisms likely possessed rudimentary proton pumps. All of these organisms likely carried out aerobic respiration. These organisms likely carried out fermentation and may have had rudimentary proton pumps.

These organisms likely carried out fermentation and may have had rudimentary proton pumps.

Which of the following is not a true statement about receptors that are localized to the nucleus? They carry a nuclear-localization signal. They were synthesized in the cytosol. They bind polar ligands. They moved through a nuclear pore.

They bind polar ligands.

The only known "solution" to the loss of efficiency caused by the oxygenating of RuBP by rubisco is to raise the concentration of CO2 at the enzyme, using ATP generated by the thylakoid. Which of the following is likely most correct of such plants? They do not produce reactive O2 species. They require bright, sunny habitats. They are tolerant of shade. They require high CO2 levels. They do not produce O2.

They require bright, sunny habitats.

A researcher has discovered a new ligand that can pass through the cell membrane and bind to a receptor in the nucleus. Which of the following statements is not likely true of this ligand? This ligand is likely a steroid. This ligand likely plays a role in transcription. This ligand is likely nonpolar. This ligand likely utilizes a transmembrane receptor. This ligand likely has a similar structure to cholesterol.

This ligand likely utilizes a transmembrane receptor.

In which of the following molecules are the electrons of the atoms shared in covalent bonds at the furthest distance from the nucleus? glucose water carbon dioxide

glucose

Which of the following statements is true regarding triacylglycerols? Triacylglycerols have no structural similarities to glycerol. Triacylglycerols can be used to generate acetyl-CoA. ATP is derived from triacylglycerols through beta-oxidation and substrate-level phosphorylation. Triacylglycerols are stored in the liver and are used to produce ATP via substrate-level phosphorylation. Like glycogen, triacylglycerols are stored primarily in the liver.

Triacylglycerols can be used to generate acetyl-CoA.

Which of the following lowers the efficiency of plants' conversion of sunlight into chemical energy? UV light, O2, and heat dissipation UV light and O2 O2 and heat dissipation UV light and heat dissipation UV light

UV light, O2, and heat dissipation

Which of the following processes is NOT part of the communication at a neuromuscular junction? An opened ligand-gated ion channel allows sodium ions to rush across the plasma membrane to the inside of the muscle cell. Upon activation, the acetylcholine receptor on the neuron undergoes a conformational change to activate an ion channel in the muscle cell. A sudden influx of sodium ions across the plasma membrane drastically reduces the membrane potential and activates the contractile machinery of the muscle cell. The neuron releases a neurotransmitter to signal contraction by the muscle cell. A cell-surface receptor on the muscle cell is activated by acetylcholine binding.

Upon activation, the acetylcholine receptor on the neuron undergoes a conformational change to activate an ion channel in the muscle cell.

What is the end result of activating the MAP kinase pathway? synthesis of second messenger molecules a change in gene expression ion flow phosphorylation of multiple cytosolic proteins

a change in gene expression

What is the likely cellular response to ligand binding to a steroid receptor located in the nucleus? initiation of a signal-transduction pathway a change in gene expression activation of a kinase alteration in ion transport

a change in gene expression

What is the immediate effect of ligand binding to a G protein-coupled receptor? the release of the alpha subunit of the G protein a conformational change in the cytoplasmic domain of the receptor the activation of an effector protein an exchange of GTP in place of GDP on the alpha subunit of the G protein

a conformational change in the cytoplasmic domain of the receptor

All photosynthetically competent cells contain __________. a plasma membrane chloroplasts mitochondria chloroplasts and mitochondria chloroplasts, mitochondria, and a plasma membrane

a plasma membrane

Energy released by transferring electrons along the electron transport chain is stored as potential energy in the form of: ATP. redox couples. coenzyme Q. ATP synthase. a proton gradient

a proton gradient

A protein on a cell surface that binds to a signaling molecule is an example of which of the following elements of cellular communication? a receptor molecule a responding cell a signaling cell a signaling molecule None of these choices are correct.

a receptor molecule

Which of the following would NOT be considered a cell-surface receptor? a receptor that allows ions to enter the cell when a ligand binds a receptor that causes GDP to be exchanged for GTP in a G protein a receptor that must form a dimer after binding the ligand to transmit a signal a receptor that binds a nonpolar steroid hormone and activates transcription

a receptor that binds a nonpolar steroid hormone and activates transcription

Signal transduction results in: a response by the cell. a change in the conformation of the receptor protein. production of more signal molecules. termination of the signal.

a response by the cell.

Signal transduction results in: production of more signal molecules. a response by the cell. a change in the conformation of the receptor protein. termination of the signal.

a response by the cell.

Signal amplification relies on: increasing numbers of cell-surface receptors as the signal is transduced. increasing amounts of ligand as signal transduction proceeds. a sequential increase in the different components of the signal transduction pathway. increased activity of protein phosphatases.

a sequential increase in the different components of the signal transduction pathway.

To what does the term ligand refer? the proteins activated as part of a signal transduction pathway the extracellular domain of a receptor protein a signaling molecule a type of gated channel

a signaling molecule

The signaling molecule involved in juxtacrine cell signaling is: a transmembrane protein. a growth factor. a small soluble peptide. a neurotransmitter. 2.3

a transmembrane protein.

From its ground state, PSII can __________. pull electrons from H2O pull protons from H2O emit light energy absorb light energy pass electrons to PSI

absorb light energy

Certain complexes of the mitochondrial electron transport chain pump protons. Which of the following best describes the movement of protons in this situation? across the outer mitochondrial membrane, from the cytoplasm to the intermembrane space across the outer mitochondrial membrane, from the intermembrane space to the cytoplasm across the inner mitochondrial membrane, from the intermembrane space to the matrix across the inner mitochondrial membrane, from the matrix to the intermembrane space

across the inner mitochondrial membrane, from the matrix to the intermembrane space

To have communication between cells you must have a

all

In the electron transport chain, which of the following electrons would have the lowest amount of energy? an electron bound to CoQ an electron bound to NADH an electron bound to cytochrome c an electron bound to oxygen (in the form of H2O) All of these electrons would have an equivalent amount of energy.

an electron bound to oxygen (in the form of H2O)

Glycolysis is: aerobic. anaerobic. aerobic in some organisms but a anaerobic in others. aerobic in some tissues but anaerobic in others. None of the answer options is correct.

anaerobic

In which form are electrons transferred during typical redox reactions such as the oxidation of glucose? as free electrons as hydrogen atoms as oxygen atoms as carbon atoms as phosphate groups

as hydrogen atoms

Which of the following is a type of cell communication where the signaling molecule is released by the same cell that responds to the signal? endocrine paracrine All of these choices are correct. juxtacrine autocrine

autocrine

in your experiment system you create a cell that has a mutation in its receptor. when you overexpress the cell's signaling molecule, nothing happens. what is the cell defective in

autocrine signaling

Lactic acid fermentation occurs in (select all correct answer options): animals and fungi. animals and plants. plants and bacteria. fungi and bacteria. bacteria and animals.

bacteria and animals.

The breakdown of fatty acids takes place via a process called: oxidative phosphorylation. beta-carboxylation. glycolysis. fatty acid phosphorylation. beta-oxidation.

beta-oxidation

The breakdown of fatty acids takes place via a process called: beta-oxidation. glycolysis. oxidative phosphorylation. fatty acid phosphorylation.

beta-oxidation.

Inactivation of a cell-surface receptor depends on: the binding affinity of the receptor. the concentration of ligand surrounding the cell. the activity of phosphatases in the cytosol. both the binding affinity of the receptor and concentration of ligand surrounding the cell.

both the binding affinity of the receptor and concentration of ligand surrounding the cell.

How did the earliest organisms on Earth most likely produce ATP? by acetyl CoA synthesis by glycolysis by the citric acid cycle by oxidative phosphorylation

by glycolysis

Cellular respiration is a series of _____ reactions. catabolic phosphorylation carboxylation anabolic glycolytic

catabolic

The second phase of glycolysis: generates ATP by substrate level phosphorylation. phosphorylates glucose. cleaves a phosphorylated sugar molecule and rearranges the products. generates ATP by oxidative phosphorylation. reduce NAD+ to NADH

cleaves a phosphorylated sugar molecule and rearranges the products.

In a normal cell, tumor suppressors are responsible for: (select all correct choices) increasing the rate of cell division. signaling the initiation of DNA replication. correcting replication errors. signaling death in a highly defective cell.

correcting replication errors. signaling death in a highly defective cell.

Electrons move between PSII and PSI via __________. chlorophyll NADPH water cytochrome b6f NADP+

cytochrome b6f

The phosphorylation of glucose during glycolysis serves to: (select all that apply) destabilize the molecule, making it easier to cleave. trap imported glucose inside the cell. reduce a biological cofactor, storing energy for later.

destabilize the molecule, making it easier to cleave. trap imported glucose inside the cell.

Phosphorylating glucose during phase 1 of glycolysis: releases phosphorylated glucose from cells. destabilizes the glucose molecule so that it can be broken down in stage 2. provides electrons to reduce NAD+ in stage 3. provides electrons to reduce FADH in stage 3. None of the answer options is correct.

destabilizes the glucose molecule so that it can be broken down in stage 2.

At what phase of glycolysis is NADH formed? during Phase 1, when fructose 1,6-biphosphate is formed during Phase 2, when glyceraldehyde 3-phosphate is formed during Phase 3, when glyceraldehyde 3-phosphate is phosphorylated during Phase 3, when pyruvate is finally formed during Phase 1, when glucose is phosphorylated

during Phase 3, when glyceraldehyde 3-phosphate is phosphorylated

Where would you expect to find the receptor for a nonpolar ligand? either in the nucleus of the cell or in the cytosol in the cytosol in the nucleus of the cell on the cell surface

either in the nucleus of the cell or in the cytosol

When glucose is broken down in a cell, all of the energy it stores is released simultaneously, not in a stepwise process. true false

false

In the first three stages of cellular respiration, the chemical energy in glucose is transferred to: ATP and cytochrome b. electron carriers and ATP. proton pumps and ATP. only coenzyme Q. cytochrome b and coenzyme Q.

electron carriers and ATP.

In the first three stages of cellular respiration, the chemical energy in glucose is transferred to: cytochrome b and coenzyme Q. ATP and cytochrome b. electron carriers and ATP. only coenzyme Q. proton pumps and ATP.

electron carriers and ATP.

Cyclic electron transport enhances ATP production because __________. electrons are transferred from ferredoxin to plastoquinone proton translocation decreases cyclic electron transport is more energy-efficient than linear electron transport ADP production increases PSI pumps more protons

electrons are transferred from ferredoxin to plastoquinone

The proteins of the electron transport chain are: embedded in the outer mitochondrial membrane. embedded in the inner mitochondrial membrane. embedded in both mitochondrial membranes. located in the intermembrane space of mitochondria. located in the mitochondrial matrix.

embedded in the inner mitochondrial membrane.

The first phase of glycolysis requires the input of two ATP molecules. It is therefore: endergonic. exergonic. oxidative. reducing. None of the answer options is correct.

endergonic.

Which signaling system involves the longest time interval between release of a signaling molecule and activation of a receptor? juxtacrine endocrine paracrine autocrine

endocrine

Cell signaling over a long distance is known as: endocrine signaling. juxtacrine signaling. paracrine signaling. autocrine signaling.

endocrine signaling.

The majority of energy generated in the citric acid cycle is in the form of: ATP via substrate level phosphorylation. GTP via oxidative phosphorylation. GTP via substrate level phosphorylation. energy electrons donated to NAD+ and FADH. ATP via oxidative phosphorylation.

energy electrons donated to NAD+ and FADH.

Antennae accompany reaction centers, promoting __________. electron transfer heat loss energy transfer H+ transfer fluorescence

energy transfer

Antennae accompany reaction centers, promoting __________. heat loss energy transfer electron transfer H+ transfer fluorescence

energy transfer

Acetyl-CoA synthesis is remarkably similar to glycolysis in that when one molecule of pyruvate enters into a mitochondrion, two molecules of acetyl-CoA are formed.

false

Acetyl-CoA synthesis is remarkably similar to glycolysis in that when one molecule of pyruvate enters into a mitochondrion, two molecules of acetyl-CoA are formed. true false

false

By the time pyruvate is formed, most of the energy contained in glucose has been released. true false

false

Collectively, most photosynthesis carried out in the ocean is performed by prokaryotes and not eukaryotes. true false

false

During the action of ATP synthase, the kinetic energy of the proton gradient is transformed into potential energy. true false

false

Eukaryotes conduct all of the photosynthesis that occurs in the ocean. false true

false

Given that most ligands form covalent bonds with their associated receptors, these complexes are more-or-less permanent and can only be broken through the use of ATP. true false

false

In a plant cell, all stages of cellular respiration are carried out in the cytoplasm. true false

false

Like glycolysis, acetyl-CoA synthesis produces both pyruvate and acetyl-CoA. These two products feed directly into the citric acid cycle and are the reactants for this process. true false

false

Malate is both the starting and ending product of the citric acid cycle. true false

false

Oxidation is the gain of electrons. true false

false

Prokaryotes account for roughly half of terrestrial photosynthesis. false true

false

The Calvin cycle is a relatively constant process, the rate of which is independent of factors such as temperature and nitrogen concentration. true false

false

The majority of ATP produced during acetyl-CoA synthesis is the result of substrate-level phosphorylation. true false

false

The majority of cells within the human body have a very high baseline amount of ATP, so cells are always prepared for any long-term activity. true false

false

Based on the data provided in the two graphs shown in Fig. 9.5, which method of culturing resulted in the greatest number of fibroblast cells on day 6? fibroblasts cultured with serum fibroblasts cultured with platelet proteins fibroblasts cultured with plasma The same results are obtained whether the fibroblasts are cultured with serum or with platelet proteins.

fibroblasts cultured with serum

During photorespiration, the phosphoglycolate (PGO) produced by RuBP oxygenation is eventually converted to PGA; 75% of the carbon in PGO is recovered. How many molecules of PGO are required to generate two molecules of PGA through this route? five four three two one

four

Which one of the following is a monosaccharide and not a disaccharide? lactose fructose sucrose maltose None of these sugars is a monosaccharide.

fructose

which type of receptor needs an accessory protein to signal

g protein coupled

In cellular respiration, oxygen: gains electrons and is an oxidizing agent. loses electrons and is a reducing agent. gains electrons and is a reducing agent. loses electrons and is an oxidizing agent. None of the answer options is correct.

gains electrons and is an oxidizing agent.

The evolution of photosynthesis involved __________. endosymbiosis convergent evolution convergent evolution and endosymbiosis horizontal gene transfer horizontal gene transfer and endosymbiosis

horizontal gene transfer and endosymbiosis

The acquisition of a relatively small amount of genetic material from an organism that is not a parent of the receiving organism is referred to as: vertical descent. horizontal gene transfer. endosymbiosis. parasitism. Darwinian evolution.

horizontal gene transfer.

Fermentation takes place: on the outer mitochondrial membrane. in the intermembrane space of mitochondria. on the inner mitochondrial membrane. in the mitochondrial matrix. in the cytoplasm.

in the cytoplasm

High temperatures increase reaction rates but lower rubisco selectivity for CO2 versus O2. High leaf temperatures thus __________. decrease photorespiration rates increase respiration increase photorespiration rates decrease RuBP carboxylation increase RuBP carboxylation

increase photorespiration rates

Paraquat is an herbicide that blocks the transfer of electrons from PSII. Mechanistically, paraquat is effective because it __________. prevents the reduction of NADPH prevents the formation of reactive oxygen species increases the formation of reactive oxygen species increases cyclic electron transport, which does not produce NADPH absorbs light energy that cannot then be used for photosynthesis

increases the formation of reactive oxygen species

PFK-1 is ___________ by ATP and ____________ by ADP. activated; activated activated; inhibited inhibited; activated inhibited; inhibited

inhibited; activated

With the endosymbiotic hypothesis in mind, what structure within modern-day chloroplasts is likely derived from the plasma membrane of ancestral cyanobacteria engulfed by eukaryotic cells? grana lumen thylakoid membrane stroma inner membrane

inner membrane

Rubisco __________. carboxylates CO2 is a primary control over the global carbon cycle controls photosynthesis reduces RuBP is only present in leaves

is a primary control over the global carbon cycle

Rubisco __________. reduces RuBP controls photosynthesis is only present in leaves is a primary control over the global carbon cycle carboxylates CO2

is a primary control over the global carbon cycle

Ras is like a G protein because it: triggers the formation of cyclic AMP. responds to the activation of G protein-coupled receptors. is only active when it binds GTP. All of these answer options are correct.

is only active when it binds GTP.

In a thylakoid membrane, absorbed light energy is passed from one chlorophyll molecule to another until: it is dissipated as heat. it is released as fluorescence. it is passed to a reaction center. it is both dissipated as heat and released as fluorescence. All these choices are correct.

it is passed to a reaction center.

Acetyl-CoA synthesis is an important step in cellular respiration because: it generates ATP by substrate level phosphorylation. it transfers large numbers of high-energy electrons to electron carriers. it is the first step in oxidative phosphorylation. it eliminates toxic pyruvate from the cell. it links glycolysis with aerobic respiration.

it links glycolysis with aerobic respiration.

Which of the following statements is true regarding a reducing agent? It loses electrons. It gains electrons. It is never oxidized. It is usually oxygen. It is an electron acceptor.

it loses electrons

Which type of protein adds a phosphate group to another molecule? kinase G protein phosphatase phosphorylase

kinase

In human cells such as muscle tissue, the product of anaerobic respiration is: acetic acid. pyruvate. lactic acid. FADH2. ethanol.

lactic acid

The primary reason surplus carbohydrates in plants are stored as starch is because: they would otherwise be utilized as energy sources even if such energy was not needed at that time. the space they occupy as carbohydrates is needed for other macromolecules. energy is needed in the nucleus, and only starch is capable of being transported into the nucleus. leaving them as individual monosaccharides would upset the osmotic balance of the cell. All of these choices represent equally important reasons why surplus carbohydrates in plants are stored as starch.

leaving them as individual monosaccharides would upset the osmotic balance of the cell.

During acetyl-CoA synthesis, pyruvate is broken down into CO2 and an acetyl group. The CO2 is: less oxidized than the acetyl group. more reduced than the acetyl group. more energetic than the acetyl group. less energetic than the acetyl group. None of the answer options is correct.

less energetic than the acetyl group.

NADPH production requires __________. electrons protons light light, electrons and protons light and protons

light, electrons and protons

ATP production requires __________. electrons light light, electrons, and protons protons light and protons

light, electrons, and protons

Low temperatures slow the activity of rubisco but enhance its ability to select CO2 over O2. Low temperatures thus __________. increase the production of reactive oxygen species increase photorespiration rates lower the production of reactive oxygen species increase photorespiration increase photosynthesis rates

lower the production of reactive oxygen species

In plants and algae, which of the following is a by-product of photosynthesis? C6H12O6 O2 CO2 H2O H+

o2

Reactive oxygen species are detoxified in order to __________. recover electrons minimize damage to membranes enhance linear electron transport enhance cyclic electron transport All answer options are correct.

minimize damage to membranes

In eukaryotes, acetyl-CoA synthesis takes place in the: cytoplasm. outer mitochondrial membrane. mitochondrial matrix. inner mitochondrial membrane. intermembrane space of mitochondria.

mitochondrial matrix

The citric acid cycle takes place in the: cytoplasm. intermembrane space of mitochondria. outer mitochondrial membrane. mitochondrial matrix. inner mitochondrial membrane.

mitochondrial matrix.

In what organelle is acetyl-CoA synthesis carried out in a cell? chloroplast nucleus mitochondrion Golgi apparatus endoplasmic reticulum

mitochondrion

which of the following statements is true regarding aerobic respiration? Aerobic respiration requires oxygen at every stage of the process. Aerobic respiration is carried out by all prokaryotes and eukaryotes. Aerobic respiration is a three-step process, with oxidative phosphorylation comprising the last stage. Carbon dioxide is produced at every stage of aerobic respiration. None of the answer options is correct.

none

Which of the following statements is true regarding pyruvate and glucose? Glucose easily passes in and out of mitochondria, and can often be found in the mitochondrial matrix. Pyruvate is typically "trapped" in the intermembrane space of mitochondria, where it is oxidized to form acetyl-CoA. Glucose and pyruvate are remarkably similar in structure, with both molecules possessing a ring shape. Both glucose and pyruvate can feed directly into the citric acid cycle, although acetyl-CoA is the preferred reactant for this process. None of the answer options are correct.

none None of the answer options are correct.None of the answer options are correct.

Which of the following statements is true regarding aerobic respiration? Aerobic respiration requires oxygen at every stage of the process. Aerobic respiration is carried out by all prokaryotes and eukaryotes. Aerobic respiration is a three-step process, with oxidative phosphorylation comprising the last stage. Carbon dioxide is produced at every stage of aerobic respiration. None of the answer options is correct.

none of the answer options is correct

Which of the following is not an end product for an acetyl group that enters the citric acid cycle? ATP NADH oxaloacetate FADH2 CO2

oxaloacetate

The citric acid cycle begins when acetyl-CoA combines with ____________ to form ____________. pyruvate; citrate malate; oxaloacetate oxaloacetate; malate oxaloacetate; citrate citrate; cis-aconitate

oxaloacetate; citrate

During the citric acid cycle, the production of CO2 is a(n) _____ reaction coupled to the production of oxidation; ATP oxidation; NADH reduction; ATP oxidation; GTP reduction;, NADH

oxidation; NADH

The electron transport chain is part of: glycolysis. the citric acid cycle. oxidative phosphorylation. fermentation. acetyl-CoA synthesis.

oxidative phosphorylation.

The electron transport chain is part of: glycolysis. the citric acid cycle. fermentation. oxidative phosphorylation. acetyl-CoA synthesis.

oxidative phosphorylation.

During acetyl-CoA synthesis, pyruvate is: oxidized. reduced. phosphorylated. hydrogenated. carboxylated.

oxidized

In the Calvin cycle, NADPH is __________. oxidized reduced phosphorylated oxidized and reduced None of the answer options is correct.

oxidized

In cellular respiration, glucose is _____ to CO2 and oxygen is _____ to water. reduced; oxidized oxidized; reduced deoxygenated; phosphorylated oxidized; oxidized phosphorylated; deoxygenated

oxidized; reduced

When an electron is transferred from NADH to CoQ, NADH is __________________ and CoQ is _____________________. oxidized; reduced reduced; oxidized oxidized; oxidized reduced; reduced

oxidized; reduced

Many photosynthetic prokaryotes are capable of cyclic electron transport only. It is likely that such organisms can __________ but not __________. produce ATP; reduce CO2 produce NADPH; reduce CO2 produce ATP; reduce H2O produce NADPH; oxidize H2O reduce CO2; synthesize carbohydrates

produce ATP; reduce CO2

Organisms with only one photosystem cannot __________. reduce CO2 produce O2 reduce H2O oxidize H2S reduce NADP+

produce O2

The occurrence of photorespiration __________ CO2 and __________ ATP. produces; produces reduces; produces oxidizes; produces produces; consumes consumes; consumes

produces; consumes

In the G protein-coupled signal transduction pathway, the enzyme phosphodiesterase is responsible for the inactivation of: the alpha subunit of a G protein. protein kinase A. adenylyl cyclase. All of these answer options are correct.

protein kinase A.

According to Fig 9.13, phosphate groups play a key role in receptor kinase activation by: providing binding sites to recruit and activate signal-transduction proteins. activating the receptor so that the receptor is capable of binding its signal. activating receptor kinase activity. activating the dimerization of the receptor kinase proteins in the membrane. All of these choices are correct.

providing binding sites to recruit and activate signal-transduction proteins.

Which is the correct order for these steps in cell signaling? receptor activation, response, then signal transduction signal transduction, receptor activation, then response response, signal transduction, then termination receptor activation, signal transduction, then response

receptor activation, signal transduction, then response

Which is the correct order for these steps in cell signaling? signal transduction, receptor activation, then response receptor activation, response, then signal transduction response, signal transduction, then termination receptor activation, signal transduction, then response

receptor activation, signal transduction, then response

In many signaling pathways, once a signaling molecule binds to a receptor, the receptor becomes phosphorylated. This initial phosphorylation step best demonstrates: signal transduction. receptor activation. cellular response. either cellular response or signal transduction. termination.

receptor activation.

Which type of cell-surface receptor undergoes changes in phosphorylation in response to binding of its ligand? G protein-coupled receptor receptor kinase both the G protein-coupled receptor and the receptor kinase ligand-gated ion channel

receptor kinase

A researcher is using a small molecule inhibitor to manipulate a signaling pathway. This inhibitor prevents phosphorylation and most likely targets a: G-protein. phosphatase. G protein-coupled receptor. ligand-gated ion channel. receptor kinase.

receptor kinase.

The _____ forms of the electron carriers NAD+/NADH and FADH/FADH2 have high potential energy. oxidized reduced phosphorylated carboxylated None of the answer options is correct.

reduced

The _____ forms of the electron carriers NAD+/NADH and FADH/FADH2 have high potential energy. oxidized reduced phosphorylated carboxylated None of the answer options is correct.

reduced

In the absence of oxygen, fermentation: regenerates NAD+ from the reduction of pyruvate. regenerates NAD+ from the oxidation of pyruvate. generates ATP from the oxidation of pyruvate. generates ATP from the reduction of pyruvate. None of the answer options is correct

regenerates NAD+ from the reduction of pyruvate.

Over evolutionary time, photosynthesis has effectively poisoned itself by producing an oxygenic atmosphere because __________. rubisco is an oxygenase rubisco is a carboxylase O2 is a strong oxidant rubisco is an oxygenase and O2 is a strong oxidant rubisco is an oxygenase and O2 is a strong reductant

rubisco is an oxygenase and O2 is a strong oxidant

The most abundant protein on Earth is: chlorophyll. cellulose. rubisco. water. keratin.

rubisco.

Cyclic AMP is an example of a(n): effector or target protein. ligand. second messenger. G protein.

second messenger.

The reaction diagrammed below: (more than one answer may apply) is the final reaction of glycolysis. is one possible pathway in the fermentation of pyruvate. shows synthesis of the substrate that enters the citric acid cycle. occurs in the cytosol. occurs in the mitochondrial matrix. occurs twice for each glucose oxidized.

shows synthesis of the substrate that enters the citric acid cycle occurs in the mitochondrial matrix. occurs twice for each glucose oxidized.

Rubisco is characterised by __________. fast catalysis slow catalysis substrate confusion slow catalysis and substrate confusion

slow catalysis and substrate confusion

The Calvin cycle and light-harvesting reactions are separated in __________. time space time and space different organelles None of the answer options is correct.

space

Consulting Figure 7.1 if necessary, during which stage(s) of cellular respiration is(are) carbon dioxide released? stage 1 only stages 1 and 2 stages 2 and 3 stage 3 only stages 3 and 4

stages 2 and 3

Referring to Figure 7.4 if necessary, determine which step in glycolysis is considered the first committed step. step 1 step 3 step 5 step 7 step 9

step 3

Which one of the following is not a cell surface-type receptor? steroid receptor ligand-gated receptor receptor kinase G protein-coupled receptor

steroid receptor

In glycolysis, ATP is synthesized via: oxidative phosphorylation. electron carriers. substrate level phosphorylation. both substrate level and oxidative phosphorylation. redox reactions.

substrate level phosphorylation.

In glycolysis, ATP is synthesized via: oxidative phosphorylation. substrate level phosphorylation. both substrate level and oxidative phosphorylation. electron carriers. redox reactions.

substrate level phosphorylation.

Which of the following citric acid cycle intermediates can be used to produce chlorophyll? Select all correct answers. α-ketoglutarate oxaloacetate succinyl-CoA

succinyl-CoA

Pyruvate can be used to produce: (select all correct choices) sugars. acetyl-CoA. alanine.

sugars. acetyl-CoA. alanine.

The amount of solar energy incorporated into chemical bonds during photosynthesis in a given year is approximately ___________ the amount of energy obtained from oil and coal in that same year. one-half one-tenth equal to one million times ten times

ten times

Which of the following signaling molecules would you expect to travel the longest distance in the human body? testosterone Delta PDGF neurotransmitters Notch

testosterone

What is the function of adenylyl cyclase? to form cyclic AMP to phosphorylate protein kinase A to phosphorylate cyclic AMP to form protein kinase A

to form cyclic AMP

GTP binding occurs on which subunit of a G protein? GTP binds both beta and gamma. the alpha subunit the gamma subunit the beta subunit

the alpha subunit

In order for a G protein to be active: both the beta and gamma subunits must bind GTP. the alpha subunit must bind GTP and the beta and gamma subunits must separate from the alpha subunit. the beta and gamma subunits must separate from the alpha subunit. the alpha subunit must bind GTP.

the alpha subunit must bind GTP and the beta and gamma subunits must separate from the alpha subunit.

Cell signaling between two nerve cells is an example of paracrine signaling because: a receptor is activated. a signaling molecule (neurotransmitter) is released. the cells are in close proximity. the responding cell releases more signaling molecule (neurotransmitter).

the cells are in close proximity.

Which group of cells shows a decrease in the rate of cell growth from Day 2 to Day 3? the cells cultured with serum Neither. Rate of both is faster. the cells cultured with plasma

the cells cultured with serum

The stroma of the land-plant chloroplast is evolutionarily derived from __________. the periplasm of cyanobacteria the thylakoid membrane the plasma membrane of cyanobacteria the plasma membrane of a eukaryotic ancestor the cytoplasm of cyanobacteria

the cytoplasm of cyanobacteria

Membrane potential is determined by: the number and types of proteins present in the plasma membrane of a cell. the number and type of phospholipids present in a membrane. the difference in concentration of ions and charged molecules across the plasma membrane of a cell. the concentration of cholesterol in a membrane.

the difference in concentration of ions and charged molecules across the plasma membrane of a cell.

The Z scheme refers to __________. the energy inputs associated with electron transport the use of H2O as an electron source the path of electrons between PSII and cytochrome b6f electron transport proton translocation

the energy inputs associated with electron transport

What determines the specificity of a receptor protein? the transmembrane domain the cytoplasmic domain the ligand-binding site

the ligand-binding site

In eukaryotic cells, the oxidation of pyruvate occurs in: the cytoplasm. the nucleus. the matrix of the mitochondria. the endoplasmic reticulum. vacuoles.

the matrix of the mitochondria.

To see if a growth-promoting factor was released from blood platelets, cells called fibroblasts were placed in a dish containing liquid cell culture medium. The medium was supplemented with either serum (collected from blood that had been allowed to clot) or plasma from blood in which the platelets had not been activated during the clotting process. The number of cells in each culture is shown in the graph. Which of the following is the dependent variable in this experiment? the number of days the cells were cultured whether the cells were cultured in serum or plasma the number of cells

the number of cells

The first thing that happens after a signaling molecule binds to a receptor is: the receptor is activated. there is a cellular response. the signal is quickly terminated to ensure a moderate response. the receptor transmits the message in a process called signal transduction.

the receptor is activated.

Which one of the following initiates signal termination? the shut down of translation the shut down of transcription the release of signal molecules from their receptors the reduction of signal amplification

the release of signal molecules from their receptors

The experiment in Figure 8.2 demonstrates that the ratio of 18O2/16O2 increases when: the water in the experiment contains 18O2. the carbon dioxide in the experiment contains 18O2. the water and carbon dioxide in the experiment both contain 18O2.

the water in the experiment contains 18O2.

The chemical bonds of carbohydrates and lipids have high potential energy because: they are strong reducing agents. they are strong oxidizing agents. they are easy to hydrolyze. their electrons are far away from the nuclei of the atoms. they are easy to phosphorylate.

their electrons are far away from the nuclei of the atoms.

Photorespiration occurs because __________. there is more O2 than CO2 in the atmosphere rubisco is a slow catalyst there is more O2 than CO2 and rubisco is a slow catalyst there is more O2 than CO2 and rubisco is a selective catalyst rubisco is a selective catalyst

there is more O2 than CO2 in the atmosphere

How many subunits make up a G protein? three two four The number is variable.

three

How does an "activated" receptor transfer information into the cell? through a conformation change by altering its ligand-binding site by decreased phosphorylation by increased translation

through a conformation change

How does an "activated" receptor transfer information into the cell? by increased translation by altering its ligand-binding site through a conformation change by decreased phosphorylation

through a conformation change

A beer maker is using yeast to make his favorite brew. How does yeast produce ethanol? through the reduction of lactic acid through the reduction of acetaldehyde, derived from pyruvate through the oxidation of acetaldehyde, derived from pyruvate through the direct reduction of pyruvate, similar to lactic acid fermentation directly from the reduction of glucose

through the reduction of acetaldehyde, derived from pyruvate

Which of the following is not an essential element involved in communication between all cells? receptor molecule responding cell signaling molecule transduction element

transduction element

Coenzyme Q and cytochrome C: transfer high-energy electrons between protein complexes of the electron transport chain. transfer high-energy electrons from NADH and FADH2 to protein complexes of the electron transport chain. transfer electrons to ATP synthase. transfer electrons to oxygen at the end of the electron transport chain. None of the answer options is correct.

transfer high-energy electrons between protein complexes of the electron transport chain.

Although cellular respiration is typically thought of as an aerobic process, glycolysis itself is actually anaerobic. true false

true

Although glycolysis produces four molecules of ATP via substrate-level phosphorylation, the net gain of ATP for the cell is two molecules. This is due to the fact that glycolysis is—at first—endergonic. true false

true

Signaling pathways have been conserved in a wide range of organisms. true false

true

Signaling pathways have been conserved in a wide range of organisms. true false

true

The ATP produced during glycolysis is the result of substrate-level phosphorylation. true false

true

The majority of organisms on Earth can carry out some form of glycolysis. true false

true

The products of the Calvin cycle are 3-carbon sugars. false true

true

True or False: fats are not an animal's primary source of energy because some tissue types like brain tissue use glucose exclusively. true false

true

True or False: one possibility is that the earliest reaction centers could have used light energy to drive the movement of electrons from an electron donor in the surrounding medium to an electron acceptor within the cell. True False

true

True or False: the electrochemical gradient in a chloroplast can have a concentration of protons 1,000 times greater on one side of a thylakoid membrane than the other. True False

true

he products of the Calvin cycle are 3-carbon sugars. false true

true

Which of the following is not one of the net final products of glycolysis? two molecules of acetyl-CoA two molecules of NADH two molecules of pyruvate two molecules of ATP

two molecules of acetyl-CoA

Which of the following is not one of the net final products of glycolysis? two molecules of acetyl-CoA two molecules of pyruvate two molecules of ATP two molecules of NADH

two molecules of acetyl-CoA

At the end of glycolysis, the carbon molecules originally found in the starting glucose molecule are in the form of: two pyruvate molecules. one pyruvate molecule. two NADH molecules. four ATP molecules. two ATP molecules.

two pyruvate molecules.

Which of the following is a mobile electron carrier in the electron-transport chain? ubiquinone cytochrome c ATP synthase

ubiquinone cytochrome c

PSI is a __________ than PSII. weaker oxidant and a stronger reductant stronger reductant stronger oxidant and a stronger reductant stronger oxidant weaker oxidant

weaker oxidant and a stronger reductant

which is not one of the steps in cell signaling signal transaction obtaining a high density of signaling peptide receptor activation termination of signal

which is not one of the steps in cell signaling

Which treatment shows an increase in cell growth rate over the entire duration of the experiment? with plasma with serum

with plasma