Biology Chapter 6, 7, 8
During cellular respiration, the breakdown of __________ releases a great deal of _________ that is then used by the cell.
glucose, energy
Eukaryotic photosynthetic organisms are also called __________.
photoautotrophs
ATP and NADPH are both used during the Calvin cycle. What is the function of each? NADPH supplies energy and ATP supplies electrons for reducing power. ATP supplies energy and NADPH fixes CO2 so it can enter the cycle. ATP supplies energy and NADPH supplies electrons for reducing power. Both ATP and NADPH supply energy to the Calvin cycle. ATP and NADPH are joined into the starter molecule, RuBP, to form glucose.
ATP supplies energy and NADPH supplies electrons for reducing power Explanation Energy from ATP is used both to create G3P and to regenerate the starter molecule, RuBP. NADPH supplies electrons to be used as reducing power.
The energy of the electrons passing along the electron transport chain is ultimately used to produce __________. Multiple Choice citric acid ADP ATP lactic acid alcohol
ATP Explanation As oxidation-reduction reactions occur down the electron transport chain, energy is released that will be used to make ATP.
Cellular respiration is a(n) _______ in which glucose is______ to form carbon dioxide and oxygen is __________ to form water.
redox reaction, oxidized, reduced
Then, carbon dioxide undergoes __________ using energy supplied by ____ and NADPH from the light reactions.
reduction, ATP
CAM Photosynthesis
representation of partitioning in space occurs in hot and dry weather aids in the conversation of water temporary stores four-carbon molecules in mesophyll cells
Sucrose, cellulose, amino acids, and starch are all made from what starter molecule in plants? Multiple Choice ATP RuBP carboxylase glyceraldehyde 3-phosphate (G3P) fructose glucose
glyceraldehyde 3-phosphate (G3P Explanation Plants are capable of forming all of the molecules that they need to function from the initial product of of the Calvin cycle. This molecule is glyceraldehyde 3-phosphate (G3P).
The reduction of carbon dioxide produces the carbohydrate ___________________________________.
glyceraldehyde-3-phosphate
The chemical equation for cellular respiration is essentially the reverse equation of _______________.
photosynthesis
The _____________ occurs in the matrix and oxidizes the __________ from glycolysis and produces acetyl-CoA that then enters the _______________.
preparatory reaction, pyruvate, citric acid cycle.
Photosynthetic organisms use a limited portion of the electromagnetic spectrum of light. This portion is called ______ light and consists of wavelengths of light from about 400 to 740 nm.
visible
Grana are stacks of thylakoids enzymes that bind CO2. pores that open to allow gas exchange. interconnecting stomata. the sites of the Calvin cycle and production of sugars.
stacks of thylakoids. Explanation Grana are stacks of thylakoids found in a chloroplast.
The process called_____________________ uses the energized phosphate groups on the intermediates to synthesize four ATP molecules.
substrate-level ATP synthesis
The production of ATP in glycolysis and the citric acid cycle is accomplished by __________. Multiple Choice the oxidation of O2 substrate-level ATP synthesis lactic acid synthesis oxidative phosphorylation the reduction of carbon dioxide
substrate-level ATP synthesis Both glycolysis and the citric acid cycle form ATP through substrate-level phosphorylation. This involves the removal of a phosphate group from a substrate by one of the enzymes in the metabolic pathway. The phosphate is then joined to ADP by that enzyme producing ATP.
In the end, glycolysis invests ________ ATP and harvests _______ ATP, resulting in a net gain of two ATP
two, four
The overall goal of the Calvin cycle is to generate energy in the form of ATP and NADPH. use carbon dioxide gas and energy to produce carbohydrates. All of the answer choices are correct. use solar energy to split water, producing oxygen gas.
use carbon dioxide gas and energy to produce carbohydrates.
The enzyme responsible for the synthesis of ATP is __________. Multiple Choice ATP synthase ATP-ase NADPH cytochrome C
ATP synthase
cancerous cells
abnormal cells undergo cell division can result from mutations due to environmental assaults undergo angiogenesis or metastasis contains an abnormal number of nuclei lacks differentiation grows in layers without restraint
Bacteria reproduce through a specialized form of ________________________ called _________________.
asexual reproduction,binary fission
Centromeres divide during metaphase.
false
If oxygen is present following __________, the cell will enter the aerobic phases of cellular respiration and these reactions take place in the mitochondria.
glycolysis
Between 500 nm and 560 nm; reflected
green light
Between 600 nm and 740 nm; absorbed
red light
When oxygen accepts electrons, water is produced as a by-product.
true
Which of the following reactions builds sugars rather than breaks them down? Multiple Choice Citric acid cycle Glycolysis Calvin cycle Preparatory reaction Electron transport chain
Calvin cycle Explanation Cellular respiration includes glycolysis, the preparatory reaction, the citric acid cycle, and the electron transport chain. The Calvin cycle, which is part of photosynthesis, builds sugar molecules.
The first step in the ____________, also known as light-independent reactions, is the __________ of carbon dioxide.
Calvin cycle, fixation
Prophase
Chromatin condenses into chromosomes nucleolus disappears spindle fibers begin to form
Which of the following is the correct sequence of events in cellular respiration? Multiple Choice Glycolysis → citric acid cycle → electron transport chain Glycolysis → electron transport chain → preparatory reaction Citric acid cycle → electron transport → glycolysis → preparatory reaction Citric acid cycle → glycolysis → electron transport chain → preparatory reaction Glycolysis → preparatory reaction → citric acid cycle → electron transport chain
Glycolysis → preparatory reaction → citric acid cycle → electron transport chain
Electron transport chain outputs
H2O, ATP, NAD+, FAD, H+ 2 H+
Which of the following is the opposite of cellular respiration? Multiple Choice Cell division Photosynthesis Hydrolysis Fermentation Dehydration synthesis
Photosynthesis Explanation During cellular respiration, carbohydrates are oxidized forming carbon dioxide. In photosynthesis, that carbon dioxide is reduced, producing carbohydrates (glucose). Thus, these processes are opposites.
What would happen if NAD+ were not available for cellular respiration? Multiple Choice There would be an increase in the number of ATP produced. There would be no effect on the number of ATP formed. Cellular respiration would stop completely. There would be a great reduction in the number of ATP formed. There would be a small reduction in the number of ATP formed..
There would be a great reduction in the number of ATP formed Explanation Ten molecules of NADH are converted to ATP through the electron transport chain, producing 30 ATP. Without the NADH, cellular respiration would yield 6-8 ATP molecules as opposed to 36-38 ATP
Between 430 nm and 500 nm; absorbed
blue light
What structure holds two sister chromatids together? Multiple Choice spindle centromere centrosome chromatin centriole
centromere
Cytokinesis is not a phase of the cell cycle; it happens after nuclear division
false
Telaphase
nucleolus reappears daughter cells form
The Calvin cycle reactions occur in bundle sheath cells in a C4 plant because rubisco is only found in mesophyll cells. to shield the Calvin cycle reactions from O2 in the leaf spaces. to allow O2 to enter bundle sheath cells. so that they are adjacent to stomata. so that H2O is not available to mesophyll cells.
to shield the Calvin cycle reactions from O2 in the leaf spaces Explanation C4 plants must close stomata to reduce water loss. Closing the stomata results in the accumulation of O2 while the amount of CO2 diminishes. The Calvin cycle reactions are performed in the bundle sheath cells to ensure that rubisco uses CO2 and not O2 .
When a portion of a chromosome breaks off and attaches to a different chromosome, this is called a Multiple Choice apoptosis event. translocation. jumping gene. suppressor event. telomerase.
translocation. Explanation When the chromosomes of cancer cells become unstable, portions of the DNA double helix may be lost, duplicated, or scrambled. For example, a portion of a chromosome may break off and reattach to another chromosome. These events, called translocations, may lead to cancer, especially if it disrupts genes that regulate the cell cycle.
Cytokinesis in animal cells occurs by means of a cleavage furrow.
true
Energy to drive the formation of ATP in photosynthesis is derived from NADP+ .CO2. G3P. NADPH .the H+ gradient.
.the H+ gradient. Explanation Movement of hydrogen ions down their concentration gradient through ATP synthase is used to drive ATP formation.
Yeast is used to make bread rise by producing ________ during fermentation. Multiple Choice O2 gas heat CO2 gas lactic acid glucose
CO2 gas Explanation Yeasts are good examples of microorganisms that generate ethyl alcohol and CO2 when they carry out fermentation. When yeast is used to leaven bread, the CO2 makes the bread rise.
Which of the following events do NOT occur in prophase of mitosis? Multiple Choice DNA condenses to form chromosomes. The nuclear membrane breaks down. The nucleolus breaks down. Chromosomes are replicated. The mitotic spindle begins to form.
Chromosomes are replicated
Metaphase
Chromosomes line up in at the equator spindle fibers attach to chromatids
The last stage of the Calvin cycle acts to recycle ______, sending it back to aid in _______ again. G3P; light reactions RuBP; carbon fixation 3PG; light reactions 3PG; carbon fixation
RuBP; carbon fixation
The chlorophyll a molecules in the reaction center of a photosystem participate directly in the capture of solar energy. What is the purpose of the accessory pigments? They change the color of the leaves to discourage predators. They have no purpose. They absorb additional wavelengths of light and pass on the energy to the chlorophyll a in the reaction center. They participate in the Calvin cycle. They split the water molecule to supply electrons to the chlorophyll a in the reaction center.
They absorb additional wavelengths of light and pass on the energy to the chlorophyll a in the reaction center. Explanation The chlorophyll a in the reaction center is only able to accept certain wavelengths of light. The accessory pigments capture other wavelengths and pass the energy on to the chlorophyll a in the reaction center.
Which of the following statements about microtubules during anaphase is TRUE? Multiple Choice Those attached to chromosomes elongate, whereas those that are unattached shorten. Those attached to chromosomes shorten, whereas those that are unattached elongate Both attached and unattached microtubules shorten. Both attached and unattached microtubules elongate. Both attached and unattached microtubules elongate at first and then shorten.
Those attached to chromosomes shorten, whereas those that are unattached elongate.
Rb gene
Tumor suppressor gene that causes Retinoblastoma Requires mutations in both alleles before cancer can develop
Which of the following organisms can perform photosynthesis? vertebrates fungi invertebrates animals algae
algae Explanation Plants, cyanobacteria, algae, and some protists are capable of photosynthesis
In _______________ cells, the gene for telomerase is turned on, allowing cells to continue replication indefinitely.
cancer
Cells that do not receive the correct signals to move from G1 into S phase will enter G0 and therefore will be able to produce gametes through meiosis. never be able to undergo mitosis. stay in an undifferentiated state and become stem cells. immediately move into the mitotic phase. not undergo mitotic division unless it later receives the go-ahead signal.
not undergo mitotic division unless it later receives the go-ahead signal. Explanation The G0 phase is a nondividing stage that cells enter. Some cells in this phase can receive the go-ahead signal and proceed into S phase and others will never leave G0.
C₄ Photosynthesis
occurs in warm climates carried out by food crops like corn the Calvin Cycles occurs in the bundle sheath cells Pumps a four-carbon in the bundle sheath cells a representation of partitioning in space
The energy for photosynthesis arrives at the earth as _______.
sunlight
Germ cells and stem cells have enzymes called _______________, which serve to rebuild telomeres.
telomerase
Repeating DNA sequences found at the end of chromosomes are called ____________.
telomeres
If a cell stops at the G1 checkpoint, this is most likely due to what problem? there is DNA damage the chromosomes are not aligned properly the DNA has not finished replicating the cell is cancerous the chromosomes are not properly attached to the spindle
there is DNA damage Explanation The cell stops at the first checkpoint during G1 if there is DNA damage or if the proper growth signals are missing.
The process by which light energy is converted to chemical energy begins in the _______.
thylakoid
By accepting electrons, serving as the final electron acceptor, oxygen is reduced to form water. In this manner, a water by-product is formed during the electron transport chain.
true
The NADH and FADH2 molecules that are used during the reactions of the electron transport chain are derived from glycolysis, the preparatory reactions, and the citric acid cycle.
true NADH and FADH2 are by-products of glycolysis, the preparatory reactions, and the citric acid cycle. They are used as electron carriers to bring high-energy electrons to the electron transport chain.
How many total ATP are produced during glycolysis? Multiple Choice 36 4 2 14 38
4 Explanation During glycolysis, there is a total of 4 ATP produced. Glycolysis requires 2 ATP to get started and then produces 4, so there will be a net gain of 2 ATP from glycolysis.
In the energy-investment step, two ______ molecules are broken down, resulting in two _________.
ATP, ADP + P
Which of the following is a characteristic of cancer cells? Multiple Choice produced by a mutation of a proto-oncogene travel through the bloodstream to other parts of the body All of the above answers are characteristics of cancer cells. stimulate the growth of blood vessels have abnormal chromosomes
All of the above answers are characteristics of cancer cells.
Which of the following is characteristic of cancer cells? Multiple Choice cells that lack differentiation cells that have lost contact inhibition cells with abnormal nuclei cells that have uncontrolled cell division All of the above are characteristics of cancer cells.
All of the above are characteristics of cancer cells. Explanation Cancer is a disease of the cell cycle. When cells have abnormal nuclei, lose contact inhibition, lack differentiation, and have uncontrolled growth, these are all signs of cancerous cells.
What happened to the hamburger you had for lunch? Carbohydrates and fats were converted to ATP, while only proteins were used to make new molecules for the cell. All of the fats and proteins were converted to ATP, while only the carbohydrates were used to make new molecules for the cell. All of the carbohydrates were converted to ATP, while the fats and proteins were used to make molecules for the cell. Carbohydrates, fats, and proteins were converted to ATP or used to make new molecules for the cell. All of the proteins were converted to ATP, while both the fats and carbohydrates were used to make new molecules for the cell. .
Carbohydrates, fats, and proteins were converted to ATP or used to make new molecules for the cell. Explanation Besides carbohydrates, glycerol and fatty acids from fats and amino acids from proteins can undergo cellular respiration by entering glycolysis and/or the citric acid cycle. These metabolic pathways also provide substrates for the synthesis of fats (both the glycerol and fatty acids) and proteins
Cells grown in a petri dish tend to divide until they form a thin layer covering the bottom of the dish. Which of the following statements explains why this occurs? Most cells grown in petri dishes have gone through apoptosis. The cells have differentiated into more specialized cells. The cells become deficient in cyclin. Cell division can be inhibited by the proximity of other cells of the same type, a process called contact inhibition. The petri dish inhibits the cells' growth.
Cell division can be inhibited by the proximity of other cells of the same type, a process called contact inhibition. Explanation Cells continue to grow as long as there is empty space. When cells come into contact with other cells they stop growing, a process called contact inhibition.
Which of the following describes what will happen if there is a lack of oxygen during cellular respiration? Nothing will change since oxygen is not required for cellular respiration Carbon dioxide will start to diffuse into the cell There will be a lack of RUBP produced during the Calvin cycle Cellular respiration will shift towards anaerobic respiration The number of ATP produced will increase
Cellular respiration will shift towards anaerobic respiration Explanation Overall, the role of oxygen in cellular respiration is to act as the final acceptor of electrons in the electron transport chain. In the absence of oxygen the cell will shift towards anaerobic respiration.
Electron transport chain inputs
FADH2, NADH, ADP +P,
Nuclear division occurs during Multiple Choice S and G2 phases G0 phase M phase G1 and S phases G2 and M phases
G0 phase Explanation Mitosis (M phase) is nuclear division. Mitosis occurs after interphase in the cell cycle.
The drug chloral hydrate prevents elongation of microtubules. During which stage of the cell cycle would chloral hydrate be most harmful? Multiple Choice cytokinesis M phase G1 G2 S phase
M Phase Explanation During prophase of M phase, spindle fibers attach to the centromeres of the duplicated chromosomes and pull the chromosomes to the midline of the cell. If chloral hydrate prevents elongation, then the spindle fibers would not form correctly and the chromosomes would not be moved.
The _______ from the light reactions is used to reduce CO2 to a carbohydrate using energy derived from ______. Multiple Choice NADPH; ATP NADPH; RuBP rubisco; RuBP NADP+; ATP RuBP; ATP
NADPH; ATP Explanation Electrons derived from the light reactions are carried by NADPH. These electrons, along with the energy provided by ATP, are used in the Calvin cycle reactions to reduce CO2 to G3P, a carbohydrate.
Carotenoids are found in high concentrations in yellow and orange leaves or vegetables. Why do these leaves and vegetables appear yellow or orange? The carotenoids absorb or reflect yellow and orange wavelengths of light. The carotenoids absorb all wavelengths of light and then transmit yellow and orange wavelengths. The carotenoids reflect and transmit yellow and orange wavelengths of light. The carotenoids absorb or transmit yellow and orange wavelengths of light. The carotenoids absorb yellow and orange wavelengths of light.
The carotenoids reflect and transmit yellow and orange wavelengths of light Explanation Whatever wavelengths of light that a pigment does not absorb are either transmitted or reflected. These transmitted or reflected wavelengths are what our eyes perceive.
Plants cells order of cytokinesis
Vesicles derived from the Golgi complex apparatus are assembled in the center of the cell to form the cell plate. 1 The cell plate grows outward towards the cell membrane at the perimeter of the cell. 2 Cellulose within the vesicles is laid down between the new membranes. 3 Two cells with separate cell walls result
An oncogene is more likely to lead to cancer than a mutant tumor suppressor gene because Multiple Choice a gain of function mutation in an oncogene need only occur in one allele before it disrupts control of the cell cycle. a gain of function mutation in an oncogene is more likely to cause the other allele to mutate. a gain of function mutation in a tumor suppressor gene can promote the cell cycle. the mutant oncogene may inactivate telomerase. a loss of function mutation in an oncogene is sufficient to cause unregulated cell division.
a gain of function mutation in an oncogene need only occur in one allele before it disrupts control of the cell cycle Explanation Gain of function mutations in tumor suppressor genes causes cells to not divide even when growth factors are present, so cancer is unlikely to result. A loss of function mutation in a proto-oncogene would cause a similar phenotype. But a gain of function mutation, even if only in one allele, may cause cancer because the protein from the mutant allele can activate the cell cycle even as the protein from the normal allele is controlled correctly.
The contractile ring observed during cytokinesis in animal cells is composed of _______ filaments
actin
Angiogenesis contributes to carcinogenesis because it Multiple Choice allows tumor cells to invade underlying tissues. causes additional mutations to occur in tumor cells. causes apoptosis in tumor cells. allows tumor cells to spread to other parts of the body. causes blood vessels to grow into the tumor.
causes blood vessels to grow into the tumor. Explanation Angiogenesis (angio, a vessel; and geno, to give birth) is the growth of new blood vessels. Angiogenesis is necessary for a tumor to grow beyond a certain size.
This means that all cells, from human cells to bacterial cells, undergo ________________.
cellular reproduction
What is the structure that holds together the two sister chromatids that form a chromosome? Multiple Choice nucleus nucleosome chromatin histone centromere
centromere Explanation A duplicated chromosome is composed of two identical halves, called sister chromatids, held together at a constricted region called a centromere.
Typical cell
check points occur at various points of the cell cycle enter cell cycle around 70 times apoptosis occurs when a cell is mutated or worn out produces other differentiated cells attaches to substrate and responds to inhibitory signals
Which cancer therapy can lead to side effects such as nausea and hair loss? Multiple Choice drug therapy surgery All of these can lead to nausea and hair loss. hormonal therapy chemotherapy
chemotherapy Explanation Unfortunately, radiation and chemotherapy often damage cells other than cancer cells, leading to side effects such as nausea and hair loss.
As the filaments slide past one another, the cell is pinched and a _____________________ is created around the cell's circumference
cleavage furrow
Cytokinesis
cytoplasm divides involves a cleavage furrow in animal cells follows nuclear division involves a cell plate in plant cells
A translocation may lead to cancer if it moves genes from one chromosome to another. deletes the telomere of the chromosome. activates tumor suppressor genes. affects both tumor suppressor and proto-oncogenes. disrupts control of expression of genes that regulate the cell cycle.
disrupts control of expression of genes that regulate the cell cycle. Explanation Many translocations do not affect gene expression or the cell cycle. These chromosomal rearrangements would not necessarily cause cancer. But if translocations move proto-oncogenes to another chromosome where gene expression is altered, or to where the proto-oncogene is fused to another gene, cancer may result.
If you were looking under the compound light microscope at an onion root tip, in what stage of the cell cycle would the majority of the cells be? Multiple Choice metaphase prophase anaphase interphase cytokinesis
interphase Explanation Cells spend the majority of their time in interphase. Therefore, when looking at a large number of cells, the majority of the cells would be in interphase.
Which of the following is mismatched? Multiple Choice G2 stage - metabolic preparation for mitosis S stage - DNA synthesis M stage - mitosis and cytokinesis G1 stage - cell grows in size and cell organelles increase in number interphase - shortest stage of the cell cycle
interphase - shortest stage of the cell cycle Explanation Interphase is the longest part of the cell cycle.
The mitotic spindle fibers attach to chromosomes via special structures termed __________. Multiple Choice centrioles asters kinetochores centrosomes keratins
kinetochores
BRCA1 and BRCA2
mutant tumor suppressor genes that cause breast cancer inherited in an autosomal recessive manner
Interphase
period of the cell cycle between cell divisions
The transfer of the __________provides the energy that activates the ________ so that they can undergo the energy-havesting reactions.
phosphates , substrates
Plant cells and animal cells differ in cytokinesis because Multiple Choice animal cells need to build a cell membrane, while plant cells do not. plant cells need to build a cell wall, while animal cells do not. plant cells divide by mitosis, while animal cells divide by meiosis. animal cells need to build a cell wall, while plant cells do not. animal cells are living, while plant cells are not.
plant cells need to build a cell wall, while animal cells do not. Explanation During cytokinesis, plants need to construct a cell wall between the daughter cells. Animal cells, which do not have a cell wall, pinch into two new cells using a cleavage furrow.
RET gene
proto-oncogene associated with thyroid cancer Only one copy of the gene is required for cancer to develop
Humans reproduce through a form of cellular reproduction known as ________________________, which involves an egg and a sperm and introduces ____________ to the offspring.
sexual reproduction,variation
A centromere holds together two Multiple Choice centrosomes. centrioles. sister chromatids spindle fibers. non-sister chromatids.
sister chromatids Explanation The two halves of a chromosome (the original DNA and the copy) are attached via the centromere. Each half is called a sister chromatid because they carry the same genetic information.
Anaphase
sister chromatids separate daughter chromosomes form
The term metastasis refers to the fact that cancer cells tend to Multiple Choice divide. spread. shrink. destroy. decline.
spread Explanation Traveling to other body sites from point of production is a characteristic of cancer cells. This traveling seeds other body regions with the rapidly dividing cells, thus spreading cancer.
These sequences promote chromosomal _________ for replication, preventing essential _________ from being deleted
stability, genes
The final steps of the citric acid cycle produce ATP via ________ ATP synthesis.
substrate-level
If cancer is discovered at an early stage, which treatment method is most often used? Multiple Choice radiation hormonal therapy chemotherapy surgery drug therapy
surgery Explanation Cancer treatments either remove the tumor or interfere with the cancer cells' ability to reproduce. For many solid tumors, removal by surgery is often the first line of treatment. When the cancer is detected at an early stage, surgery may be sufficient to cure the patient by removing all cancerous cells.
Ben was looking at onion root tip cells under the microscope in biology class. He saw one cell that had two nuclei within it. What stage of the cell cycle was this cell in? Multiple Choice anaphase interphase metaphase prophase telophase/cytokinesis
telophase/cytokinesis Explanation A cell with two nuclei is indicative of telophase.
The G2 checkpoint prevents the cell cycle from continuing until the centrosomes have duplicated. all the organelles have been duplicated. the chromosomes are properly attached to the spindle fibers. the DNA has finished replicating. it is known for sure if the cell will divide.
the DNA has finished replicating Explanation The cell cycle halts momentarily at the G2 checkpoint in order to verify that the DNA has finished replicating. Additionally, if the DNA is damaged, the cell cycle will not continue until it has been repaired.
A tumor suppressor gene undergoes a mutation that causes it to lose its normal function. What would be the most likely result of this mutation? Multiple Choice the cell loses contact inhibition even when it is not surrounded by other cells the cell cycle accelerates the cell no longer responds to signals that cause it to stop dividing or undergo apoptosis the cell stops dividing permanently and will never re-enter the cell cycle the cell cycle halts and reverses back to the G0 stage
the cell no longer responds to signals that cause it to stop dividing or undergo apoptosis Explanation Tumor suppressor gene products inhibit the cell cycle, so lifting the inhibition through loss of a tumor suppressor would render the cell unable to stop the cell cycle even when it is receiving signals to stop or to undergo apoptosis.
What would occur in a cell if the production of cyclins halted during the cell cycle? organelles would not be duplicated in G1 the cell would not complete cytokinesis the cell would continue to divide indefinitely the cell would remain in the G2 phase and would not enter into mitosis the cell would enter the G0 phase
the cell would remain in the G2 phase and would not enter into mitosis Explanation Researchers have identified a series of internal signals called cyclins. The levels of these proteins increase and decrease as the cell cycle progresses; therefore, they act as cellular timekeepers. The appropriate cyclin has to be present at the correct levels for the cell to proceed from the G1 phase to the S phase, and from the G2 phase into the M phase.
Between 560 nm and 600 nm; reflected
yellow light
Arrange the following electron acceptors in the proper order in which they participate in electron transport. 1 = Cytochrome c 2 = Oxygen 3 = Cytochrome c oxidase 1, 2, 3 1, 3, 2 2, 3, 1 3, 1, 2 3, 2, 1
1, 3, 2
Glycolysis and the citric acid cycle are similar in that they both produce __________. NADH CO2 ATP ADP NADH and ATP
NADH and ATP Explanation NAD+ accepts electrons and hydrogen ions and is consequently reduced to NADH in both reactions. ATP is also produced in both reactions.
The electrons that are transferred through the electron transport system initially belonged to __________. NADH FADH2 ATP oxygen NADH and FADH2
NADH and FADH2
Where do the electrons come from that are used in the electron transport chain? Multiple Choice FADH2 NADH and FADH2 ADP ATP NADH
NADH and FADH2 Explanation The electron transport chain located in the cristae of mitochondria is a series of carriers that pass electrons from one to the other. NADH and FADH2 deliver electrons to the chain.
The citric acid cycle starts with ________ and yields ________. Multiple Choice carbon dioxide; oxygen acetyl-CoA; lactic acid or alcohol glucose; 32 ATPs lactic acid; carbon dioxide acetyl-CoA, NAD+, FAD, and ADP; carbon dioxide, NADH, FADH2, and ATP
acetyl-CoA, NAD+, FAD, and ADP; carbon dioxide, NADH, FADH2, and ATP Explanation During the citric acid cycle, the acetyl group (from the preparatory reaction) is oxidized in the process forming CO2. Both NAD+ and FAD accept electrons and hydrogen ions, resulting in NADH and FADH2. Substrate-level ATP synthesis occurs and ATP results.
The transfer of hydrogen ions across the membrane generates a potential energy gradient.
false
As a result of glycolysis, there is a net gain of ________ ATP. Multiple Choice 2 0 4 36 12
2 Explanation Two ATP are used to start glycolysis, and 4 ATP are produced by substrate-level ATP synthesis. Therefore, there is a net gain of 2 ATP.
Where in the cell are both NAD+ and FAD reduced to form NADH and FADH2? Multiple Choice Mitochondrial matrix Thylakoids Outer mitochondrial membrane Intermembrane space Cristae
Mitochondrial matrix Explanation NADH and FADH2 are both products of the citric acid cycle, which takes place in the mitochondrial matrix.
C₃ Photosynthesis
Occurs with moderate temperature and rainfall Named for 3PG Processes occur entirely within mesophyll cells
Which of the following is necessary for the complete breakdown of glucose? Multiple Choice ADP Carbon dioxide Water ATP Oxygen
Oxygen Explanation Oxygen, which is a reactant in cellular respiration, is necessary for the complete breakdown of glucose.
during the citric acid cycle the acetyl group is ________ and NAD⁺ and FAD⁺ are _________ to NADH and FADH₂.
oxidized,reduced
The overall process of glycolysis is responsible for breaking down one glucose molecule into __________. 1 molecule of pyruvate and 1 molecule of ATP 2 molecules of pyruvate and 2 molecules of ATP 1 molecule of pyruvate and 2 molecules of ATP 2 molecules of pyruvate and 1 molecule of ATP
1 molecule of pyruvate and 2 molecules of ATP
The Calvin cycle starts with a process known as carbon fixation, where ___ carbon dioxide molecule(s) is(are) "fixed" from a gaseous form to a solid 6-carbon molecule. 1 2 3 4
3
The electron transport chain produces _________ ATP. 32 to 36 2 to 4 very little 45 to 50
32 to 36
How does a cell capture energy from the electron transport chain? Energy is produced as electrons move from one membrane protein to the next in the electron transport chain. The cell can capture this energy to produce ATP. Each membrane protein in the chain is destroyed, releasing energy for the cell to use. The cell cannot harness energy in the electron transport chain; this harvesting happens later. Essentially, energy is produced as the electrons move backwards down the electron transport chain. As ATP is used up, energy is harvested.
Energy is produced as electrons move from one membrane protein to the next in the electron transport chain. The cell can capture this energy to produce ATP
What two things are added to NADP+ to convert it into NADPH? H+ and electrons electrons and CO2 H+ and CO2 H+ and ATP electrons and ATP
H+ and electrons Explanation NADPH carries both electrons and protons into the Calvin cycle reactions.
The O2 given off during photosynthesis is derived from both CO2 and H2O. NADP+. H2O. CO2. RuBP.
H2O Explanation The "leftover" from the splitting of water is ½O2, which combines with another ½O2 to form O2.
The light reactions of photosynthesis are said to be similar to a battery because they form a current. In which direction do the electrons of this circuit flow? NADPH → PSII → electron transport chain → PSI → electron transport chain → NADP+ H2O → PSII → chlorophyll b → PSI → chlorophyll a → NADPHPSI → electron transport chain → PSII → electron transport chain → NADPH H2O → PSII → electron transport chain → PSI → electron transport chain → NADPH NADP+ → PSII → electron transport chain → PSI → electron transport chain → NADPH
H2O → PSII → electron transport chain → PSI → electron transport chain → NADPH Explanation The overall process is much like a battery where the electrons (and energy) flow from H2O → PSII → electron transport chain → PSI → electron transport chain → NADPH.
During the four stages of cellular respiration, energy is released when the ______ of glucose are broken down and then used to make the energy molecule ________.
bonds, ATP
In photosynthesis, the light reactions ________ while the Calvin cycle ________. use products manufactured in the dark reactions; creates products used in the dark reactions require the presence of ATP; makes ATP can only function if the stomata are open; can only occur if the stomata are closed capture solar energy; converts the captured energy to chemical potential energy can occur only in the light; can occur only in the dark
capture solar energy; converts the captured energy to chemical potential energy Explanation Solar energy is captured during the light reactions and used to make ATP and NADPH, which are used in the Calvin cycle to make sugars.
A plant that uses CAM photosynthesis is most likely to be successful in what type of environment? hot, dry cool, dry cool, moist semi-tropical hot, moist
hot,dry Explanation CAM photosynthesis partitions the processes by time, performing Calvin cycle reactions only when stomata open at night to let in CO2 from the air. This minimizes water loss because of the extreme heat and low humidity.
The removal of electrons and hydrogen ions from a substrate is called what? metabolism oxidation phosphorylation reduction an enzyme-substrate complex
oxidation
The Calvin cycle reactions, which take place in the stroma, are responsible for the synthesis of glucose.
true
The chloroplasts house the structures required for photoautotrophs like plants to undergo photosynthesis, namely the stroma and the thylakoids
true
The citric acid cycle is responsible for producing the bulk of the ATP generated during cellular respiration.
false The citric acid cycle only produces 2 ATP molecules. The electron transport chain produces 32-34 ATP molecules
The overall goal of the electron transport chain is to break down glucose molecules into pyruvate, producing 2 ATP molecules.
false The overall goal of the electron transport chain is to harvest the energy in electrons carried by NADH and FADH2 molecules.
The reactions that make up cellular respiration occur entirely within the mitochondria of cells.
false The reactions that make up cellular respiration occur both in the cytoplasm and the mitochondria of cells.
Which compounds link the light reactions with the Calvin cycle reactions? ATP and NADPH H+ and G3P G3P and NADPH H+ and ATP G3P and ATP
ATP and NADPH Explanation The light reactions and the Calvin cycle reactions are dependent upon one another. The light reactions supply ATP and NADPH to the Calvin cycle, and the Calvin cycle supplies NADP+ and ADP to the light reactions.
The second stage of the Calvin cycle needs an input of energy to reduce the 3PG molecules that resulted from the first stage. Where does this energy input come from? ATP and NADPH that were supplied through cellular respiration ADP and NADP+ that were supplied through the light reactions high-energy electrons that were supplied through the harnessing of solar energy ATP and NADPH that were supplied through the light reactions
ATP and NADPH that were supplied through the light reactions
The light reactions produce ________, which are used in the Calvin cycle. The Calvin cycle releases ________, which return to the light reactions. glucose and O2; CO2 and H2O ADP and NADH; ATP and NADPH ATP and CO2; glucose and O2 ATP and NADPH; ADP and NADP CO2 and H2O; glucose and O2
ATP and NADPH; ADP and NADP Explanation The products of the light reactions, ATP and NADPH, supply energy and reducing power to the Calvin cycle. The byproducts of the Calvin cycle, ADP, inorganic P, and NADP, are returned to the light reactions.
Why is it necessary for ATP to be used in the energy-investment phase of glycolysis? There is no purpose to adding the phosphate to the glucose; it just happens that way. The addition of the phosphate is necessary to produce NADH. Adding the phosphate to the glucose makes it more stable and less likely to break apart. The energy that is released when ATP becomes ADP is harnessed and used to pump hydrogen ions across the mitochondrial membrane. Adding the phosphate activates the glucose, making it easier to break it apart.
Adding the phosphate activates the glucose, making it easier to break it apart Explanation When phosphate is added to glucose, it activates the molecule (by making it unstable), which makes it easier to break apart during the energy-harvesting steps.
Based on the number of ATP generated during the electron transport chain for every one glucose molecule, how many ATP would be generated if 10 glucose molecules were broken down? Between 32 and 34 ATP molecules Between 62 and 68 ATP molecules Between 320 and 340 ATP molecules 10 ATP molecules
Between 320 and 340 ATP molecules
The three stages of the Calvin cycle reactions are Multiple Choice NADPH reduction, CO2 fixation, and RuBP regeneration. CO2 reduction, NADPH reduction, and CO2 regeneration. CO2 fixation, CO2 reduction, and RuBP regeneration. CO2 fixation, CO2 reduction, and NADP+ regeneration. NADPH reduction, CO2 fixation, and NADP+ regeneration.
CO2 fixation, CO2 reduction, and RuBP regeneration Explanation CO2 enters the cycle during the CO2 fixation step, where it is attached to RuBP. Energy from NADPH and ATP are used to reduce the CO2 during CO2 reduction, and then five molecules of G3P that result are used to regenerate RuBP. This step also requires ATP.
Which of the following is mismatched? Multiple Choice Glycolysis - cytoplasm Where the H+ ions are located before flowing through an ATP synthase complex - intermembrane space ATP production in the electron transport chain - cristae of mitochondria Preparatory reaction - cristae of mitochondria Citric acid cycle - matrix of mitochondria
Preparatory reaction - cristae of mitochondria Explanation The preparatory reaction takes place in the matrix of the mitochondria. Pyruvate is broken down into a two-carbon acetyl group by coenzyme A.
The purpose of the preparatory reaction is to break down ________ into ________ so it can enter the citric acid cycle. Multiple Choice pyruvate; acetyl-CoA pyruvate; carbon dioxide glucose; acetyl CoA acetyl-CoA; pyruvate
pyruvate; acetyl-CoA
A new species of plant is discovered and you are asked to help classify it. Upon examination under a microscope, you find that there is a layer of bundle sheath cells containing chloroplasts around the vein of the leaf of the plant. What can you tell about the plant from this information? This plant uses chemosynthesis rather than photosynthesis. This plant falls into the category of CAM-type plants. This plant very likely carries out C4 photosynthesis. This plant is unlike any other plant that has ever been discovered and is a completely new category of plant. This is a C3 type of plant.
This plant very likely carries out C4 photosynthesis Explanation C4 plants have chloroplasts in the bundle sheath cells surrounding the veins where the Calvin cycle is carried out. Neither C3 nor CAM plants have this leaf anatomy.
A family took their newborn to the doctor. They were worried something was wrong because the baby seemed to be in constant pain. After medical tests revealed the baby had large amounts of lactic acid accumulating in his muscle cells, doctors diagnosed the child with a rare disease in which mitochondria are missing from skeletal muscle cells. How might the lack of mitochondria explain the large amounts of lactic acid in the baby's muscle cells? Without the mitochondria, the muscle cells cannot split glucose into pyruvate. As the glucose accumulates in the cell it is converted into lactic acid. In the absence of mitochondria, the muscle cells spend too much in the citric acid cycle. This results in a buildup of NADH and FADH2, which break down into lactic acid if they are unable to proceed to the electron transport chain. Because of the lack of mitochondria, the muscle cells require extremely high levels of oxygen to function. This additional oxygen requires lactic acid to produce energy. Without mitochondria, the muscle cells use fats and proteins rather than carbohydrates to generate energy. The breakdown products from the fat and proteins leads to an accumulation of lactic acid. Without mitochondria, the muscle cells are going through fermentation to produce energy. This leads to an accumulation of lactic acid.
Without mitochondria, the muscle cells are going through fermentation to produce energy. This leads to an accumulation of lactic acid. Explanation Lactic acid fermentation occurs in normal animal muscle cells when there is a lack of oxygen. In this case, lactic acid fermentation is the only option in the baby's muscles cells. Without the mitochondria, the end products of glycolysis will only be able to go through fermentation. This would produce only a fraction of the energy that the muscle cells need to function.
. As climate change leads to drier and drier summers in the southeastern United States, more and more homeowners find that they have crabgrass growing in their yards. The reason for this is that Multiple Choice crabgrass is a type of C3 plant that does well in dry climates. crabgrass is a tropical plant that likes hot, dry climates. crabgrass is a type of cactus, so it grows better in dry climates. as the climate changes, homeowners are not caring for their yards as well. crabgrass is a type of C4 plant that does well in dry climates.
crabgrass is a type of C4 plant that does well in dry climates Explanation Since it is a C4 plant, crabgrass is able to outcompete the C3 grasses that are commonly grown in yards.
In the energy-harvesting steps, ___________and__________ ions are removed from the substrates and captured by NAD+, producing two NADH.
electrons and hydrogen ions
the movement of protons through ATP synthase occurs from the __________. matrix to the intermembrane space matrix to the cytoplasm intermembrane space to the matrix intermembrane space to the cytoplasm cytoplasm to the intermembrane space
intermembrane space to the matrix
The terminal electron acceptor in the electron transport chain is water.
false The terminal electron acceptor in the electron transport chain is oxygen, which produces water.
The cycle turns twice per original molecule of glucose, resulting in ______ carbon dioxide, six NADH, two FADH₂, and ________ ATP.
four, two
Light from the sun can best be described as having both wave and particle nature. large units called particles. small units called electrons. waves called oscillations.
having both wave and particle nature
Proteins in the electron transport chain pump __________ ions across a membrane.
hydrogen
Cytochromes can best be described as __________. electron carriers that help catalyze reactions energy currency for the cell metabolites produced in the first stages of cellular respiration membrane proteins that house the electron transport chain
membrane proteins that house the electron transport chain
CAM photosynthesis limits CO2 fixation to nighttime hours in order to allow water to enter leaf spaces during the daylight hours. allow NADPH and ATP to enter leaf spaces. limit the Calvin cycle reactions to nighttime only. limit water uptake from the soil during daytime hours. open stomata only at night, limiting water loss because of heat and low humidity.
open stomata only at night, limiting water loss because of heat and low humidity. Explanation CAM photosynthesis partitions the processes by time, performing Calvin cycle reactions only when stomata open at night to let in CO2 from the air. This minimizes water loss because of the extreme heat and low humidity.
Which of the following is a function specific to photosystem I? split water to release electrons combine hydrogen ions with an electron to form water produce NADPH build water molecules give off oxygen when stimulated by light
produce NADPH Explanation In both photosystems, electrons are passed from one chlorophyll molecule to another until they ultimately end up in one central chlorophyll a molecule. Besides energizing the central Chlorophyll a molecule, photosystem I also produces NADPH.
A product of glycolysis is __________. Multiple Choice acetyl-CoA carbon dioxide FADH2 pyruvate oxygen
pyruvate Explanation During glycolysis, a six-carbon glucose molecule is broken down into two 3-carbon molecules of pyruvate.
ATP synthase derives energy for the generation of ATP from solar energy captured by the light reactions changing the shape of the enzyme. the movement of hydrogen ions against their concentration gradient into the thylakoid space. the movement of hydrogen ions down their concentration gradient from the thylakoid space to the stroma. the splitting of H2O, which releases electrons. electrons transferred from NADPH causing the enzyme to change shape.
the movement of hydrogen ions down their concentration gradient from the thylakoid space to the stroma. Explanation As hydrogen ions diffuse down their concentration gradient through ATP synthase, ATP is produced. The hydrogen protons are pumped against their concentration gradient by the action of the electron transport chain to set up this gradient.
Inside the chloroplasts, chlorophyll is found in the thylakoid membrane stroma. thylakoid space. cytoplasm. mesophyll.
thylakoid membrane Explanation Chlorophyll molecules are found within the photosystem complexes that are embedded within the thylakoid membrane.
The light-harvesting complexes of a chloroplast are located in the ________; the enzymes of the Calvin cycle reactions are located in the ________. thylakoid space; stroma stroma; thylakoid space stroma; thylakoid membrane thylakoid space; thylakoid membrane thylakoid membrane; stroma
thylakoid membrane; stroma Explanation The photosystems are located in the thylakoid membrane; the Calvin cycle reactions occur within the semifluid stroma of the chloroplast.