BIO - EXAM 2 REVIEW
What must happen to amino acids before they can be used in catabolic reactions? A. They must be decarboxylated B. They must be deoxygenated C. They must be dehydrogenated D. They must be deaminated
D
When oxygen is unavailable during heavy exercise what process do muscle cells use for energy generation? A. Glycolysis coupled with alcohol fermentation B. Anaerobic respiration C. Aerobic respiration D. Glycolysis coupled with lactate fermentation
D
You are assembling a model of a chromosome, but begin having some trouble when you get to the step of forming chromatin loops. If you are unable to resolve this problem, what step of chromosome structure would you be unable to achieve? A. Histone/DNA complex B. Nucleosome C. Solenoid D. Rosettes
D
The physical distribution of cytoplasmic material into the two daughter cells in plant cells is referred to as: A. The gap phase B. Cytokinesis C. Binary fission D. Interphase
B
A particular chemical reaction is exergonic. What can you say about the relationship between the reactants and the products in this exergonic reaction? A. The reactants have more free energy than the products B. The reactants are likely more disordered and the products are likely more ordered C. The reactants cannot spontaneously react to generate the products D. The reactants likely have lower enthalpy than the products
A
As electrons move along the electron transport chain, they lose potential energy. How is the energy that is released used by the cell? A. The energy is used to transport protons against their concentration gradient B. The energy is used to pump electrons along the electron transport chain C. The energy is converted directly into ATP D. The energy is used to pump NAD+ into the cytoplasm so it can be used in glycolysis
A
Embryonic cell cycles allow the rapid division of cells in the early embryo. These mitotic cell cycles are much shorter in length than the mitotic cell cycles of cells in a mature organism. In the embryonic cell cycles, mitosis takes approximately the same amount of time as it does in the cell cycles of mature cells. What do you think is a result of the embryonic cycle? A. Resulting daughter cells are smaller than the mother cell in the embryonic cell cycles. B. Resulting daughter cells do not contain the same genetic information as the mother cell in the embryonic cell cycles. C. Resulting daughter cells cannot form a mitotic spindle in the embryonic cell cycle. D. Mother cells in the embryonic cell cycle spend the majority of their time in G0.
A
For a particular chemical reaction, the enthalpy of the reactants is -400 kJ. The enthalpy of the products is -390 kJ. The entropy of the reactants is 0.2 kJ/K. The entropy of the products is 0.3 kJ/K. The temperature of the reaction is 25oC. What can you conclude about this reaction? A. It is exergonic B. It is endergonic C. it is a redox reaction D. It is being catalyzed by an enzyme
A
Glycolysis is a metabolic process that is done by all cells. However, not all cells make use of another metabolic process called the Krebs cycle. What does this tell you about the evolution of these processes? A. As a metabolic process, glycolysis likely evolved prior to the Krebs cycle B. As a metabolic process, the Krebs cycle likely evolved prior to glycolysis C. Both the Krebs cycle and glycolysis likely evolved at the same time
A
Hexokinase is an enzyme that binds specifically to glucose and converts it into glucose 6-phosphate. The activity of hexokinase is suppressed by glucose 6-phosphate, which binds to hexokinase at a location that is distinct from the active site. This is an example of what? A. Feedback inhibition B. Competitive inhibition C. Cofactor binding D. Allosteric activation
A
If there are 32 sister chromatids in a normal somatic cell, what is the haploid number for that cell? A. 8 B. 16 C. 32 D. 64
A
If there were no suppression of DNA replication between meiotic divisions but cytokinesis proceeded normally, what is the most likely outcome of meiosis? A. 4 diploid cells B. 2 diploid cells C. 4 haploid cells D. 2 haploid cells E. 2 diploid cells and 2 haploid cells
A
In G2, there are typically high levels of the mitotic cyclin. Why is cdc2 not active during G2 if the mitotic cyclin is present? A. Cdc2 is also regulated by phosphorylation. B. Cdc2 does not bind to the mitotic cyclin. C. Cdc2 requires ubiquitination to be activated. D. Cdc2 also has to bind to cohesin to be activated.
A
It is summer, and you are excited about going to your local amusement park, and specifically about riding the new roller coaster that was just built. You imagine waiting at the top of the stairs for the roller coaster to pull into the station, climbing into the car, strapping yourself into the seatbelt, and pulling down the harness. You can imagine the cars slowly chugging up to the top of the first hill, coming down on the other side, and the excitement you expect to feel as you go along for the ride. Of all of the things that you have imagined, which is an example of potential energy? A. Waiting at the top of the stairs for the roller coaster to pull into the station B. Climbing into the car C. Pulling down the harness D. The roller coaster car going up the first hill
A
Kinases are enzymes that can phosphorylate (transfer phosphate groups onto) macromolecules such as proteins. A particular kinase, Kinase 1 is known to promote cell division. It promotes cell division by phosphorylating Protein X. Phosphorylation of Protein X activates Protein X. Once activated, Protein X stimulates the production of other proteins such as Protein Y and Z that directly promote cell division. In order to function, Kinase 1 requires the presence of Metal A. However, in the presence of Protein A, Kinase 1 is nonfunctional. From the description, what is considered the substrate of Kinase 1? A. Protein X B. Protein Y C. Protein Z D. Metal A E. Protein A
A
One way to generate acetyl-CoA is to convert pyruvate into acetyl-CoA by stripping off a C02 molecule. The removal of CO2 is referred to as what type of reaction? A. Decarboxylation B. Glycolytic C. Carboxylation D. Acetylation
A
RNA molecules that also act as enzymes are given the name: A. ribozymes B. cofactors C. coenzymes D. allosteric enzymes
A
The drug Taxol, or Paclitaxel, is used to treat patients with a variety of cancers, including breast, lung and ovarian cancers. The drug works by stabilizing microtubules, and preventing their disassembly. The goal of the drug is to prevent dividing cells from being able to complete mitosis. As a result, cancerous cells can no longer divide. In a cell treated with Taxol, at what stage of mitosis will the cells arrest? A. Prior to metaphase B. Anaphase C. Telophase D. Cytokinesis
A
The fusion of a male gamete with a female gamete is called A. syngamy. B. meiosis. C. mitosis. D. recombination. E. synapsis.
A
The progress of the eukaryotic cell cycle is regulated primarily by what proteins? A. Cyclins B. Histone proteins C. Condensins D. FtsZ
A
The term oxidation is derived from the name of the element oxygen. This is reasonable, because oxygen: A. attracts electrons very strongly. B. can be oxidized by accepting electrons. C. contains more electrons than are needed. D. passes electrons to many other types of molecules.
A
The ultimate source of energy for humans comes from what source? A. The sun B. Plants C. Water D. Air E. Animals
A
This process is common to all living cells: A. Glycolysis B. Alcohol fermentation C. The Krebs cycle D. Electron transport chain reactions E. Pyruvate oxidation
A
What is one of the roles of the APC/C during anaphase? A. To directly target the mitotic cyclins for destruction. B. To directly target cohesin for destruction. C. To directly target separase for destruction. D. To directly target microtubules for destruction.
A
What molecule can oxidize NADH? A. Acetaldehyde B. Lactate C. Ubiquinone D. Glucose E. Isocitrate
A
While standing at the top of the stairs, you have a potential energy of 40 Joules. If you walk all the way down the stairs, what would your potential energy be at the bottom of the stairs? A. 0 Joules B. 20 Joules C. 40 Joules D. 80 Joules
A
Why are the components of the electron transport chain embedded in the inner mitochondrial membrane rather than floating freely in the cytoplasm of mitochondrial matrix? A. To generate and maintain the proton gradient essential for ATP production. B. To separate the ATP from the ADP. C. Because electrons cannot float in the matrix. D. Because NADH cannot localize to the mitochondrial matrix.
A
Why is the energy generated from the catabolism of sugars and other macromolecules ultimately harnessed to generate ATP? A. ATP can be used by cells to drive endergonic reactions B. ATP can be used to make RNA, which is an energy storage molecule in the cell C. ATP synthesis is an exergonic reaction D. ATP is required to generate the proton gradient in the intermembrane space of mitochondria
A
ou are leading a team of researchers at a pharmaceutical company. Your goal is to design drugs that help fight cancer. Specifically, you want to focus on drugs that bind to and inactivate certain proteins, thereby halting cell cycle progression. One of your team members suggests targeting the retinoblastoma (Rb) protein and inhibiting this protein. Will this approach be successful? Why or why not? A. This approach will not be successful. Rb is tumor-suppressor protein, and functions to inhibit the action of a number of cell cycle regulatory proteins. A drug designed to inactivate the Rb protein would essentially create the same situation as in as a cell that lacks both copies of the Rb gene. Lack of Rb activity would release the inhibition of cell cycle regulatory proteins, thereby promoting cell cycle progression, rather than halting it. B. This approach will be successful. Rb is an oncogene, and functions to activate a number of cell cycle regulatory proteins. A drug designed to inactivate the Rb protein would halt the cell cycle in cells that contain an active Rb. As a result, cancer cells expressing a constitutively active Rb protein would be good targets for this type of therapeutic. C. This approach will be successful. Rb is tumor-suppressor protein, and functions to inhibit the action of a number of cell cycle regulatory proteins. A drug designed to inactivate the Rb protein would activate cell cycle inhibition. Lack of Rb activity would therfore inhibit the cell cycle regulatory proteins. D. This approach will not be successful. Rb is an oncogene, and functions to activate a number of cell cycle regulatory proteins. A drug designed to inactivate the Rb protein would actually activate cell cycle progression. As a result, this drug would likely make this situation worse for patients whose cancer cells contain mutant Rb.
A
A duplicate copy of all of the hereditary information contained in the nucleus of eukaryotic cells is made during what stage of the cell cycle? A. G1 B. S C. G2 D. Mitosis E. Cytokinesis
B
A human cell has a mutation in the gene that encodes the enzyme that generates lactate from pyruvate, rendering that enzyme completely non-functional. Assuming that there is ample glucose present, how would this cell generate energy in the presence of oxygen?
B
A new antibiotic has been developed that inhibits the activity of an enzyme by competitive inhibition. What effect will this have on the activation energy of the enzyme-catalyzed reaction? A. The activation energy required for the reaction in the presence of the antibiotic would be greater than the activation energy required in the absence of the antibiotic B. The activation energy required for the reaction in the presence of the antibiotic would be less than the activation energy required in the absence of the antibiotic C. The activation energy required for the reaction in the presence of the antibiotic will be the same as the activation energy required in the absence of the antibiotic
B
A person whose cells all contain a chromosome number of 2n+1 most likely has what type of condition? A. Monosomy B. Trisomy C. Cancer D. Obesity E. None, this is the normal chromosome number for humans.
B
During this stage of mitosis, the chromosomes become attached to the spindle at their kinetochores. A. Prophase B. Prometaphase C. Metaphase D. Anaphase E. Telophase
B
Enzyme 1 converts substrate A into product B. Is this an example of a metabolic pathway? A. Yes. This is a metabolic pathway that includes feedback inhibition. B. No. This only describes one chemical reaction. A metabolic pathway includes multiple chemical reactions. C. Yes. This is a simple metabolic pathway. D. No. A metabolic pathway must include an inhibitory step.
B
Eukaryotic chromosomes are composed of a complex of 60% protein and 40% DNA. This complex is referred to as: A. The histone complex B. Chromatin C. The kinetochore D. Cohesin
B
If citrate levels are high in the cell, but ATP levels are low, what do you think will happen in the cell? A. In the presence of glucose, glycolysis will run to generate energy for the cell, but the Krebs cycle will be inhibited. B. Glycolysis will be inhibited, but the Krebs cycle will be functional, allowing it to be utilized to breakdown acetyl-CoA generated from beta-oxidation. C. The electron transport chain will be inhibited, causing a build-up of NADH and FADH2. This will inhibit the Krebs cycle, but in the presence of glucose, glycolysis will still run coupled with fermentation to regenerate NAD+. D. Glycolysis and the Krebs cycle will both be inhibited, thus under these conditions there will be no mechanism to generate ATP.
B
If you take into account the amount of ATP generated by ATP synthase per molecule of NADH produced in aerobic respiration, the net number of ATP molecules produced by substrate-level phosphorylation, and the fact that NADH molecules produced in the cytoplasm have to be transported into the mitochondria, what is the predicted energy yield of glycolysis in eukaryotic cells? A. 2 ATP B. 5 ATP C. 7 ATP D. 32 ATP E. 30 ATP
B
In a chemical reaction, 1,3-bisphosphoglycerate + ADP yields 3-phosphoglycerate plus ATP. What is the delta G for this reaction? A. Greater than zero. B. Less than zero. C. Equal to zero. D. Cannot be determined
B
Many types of cancer cells have been detected to secrete significant levels of lactate. Do you think these cells are likely undergoing beta-oxidation? A. Yes, because beta-oxidation can generate intermediates that would lead to the production of lactate. B. No, because if lactate is being produced, the cell is not likely making use of the pathways needed to make use of the products of beta-oxidation. C. Yes, because lactate stimulates beta-oxidation. D. No, because lactate is consumed in beta-oxidation
B
Phosphofructokinase is regulated by a number of factors, including high levels of ATP. Why is this enzyme regulated by ATP levels? A. If ATP levels are high, this provides a mechanism to directly inhibit the Krebs cycle, thus preventing further generation of NADH, FADH2 and ATP molecules that are not needed. B. If ATP levels are high, it is important to directly inhibit the reaction that commits the substrate to glycolysis to allow the substrate to be available for other reactions, since the cell has ample energy. C. If ATP levels are high, it is important to inhibit ATP synthase, and phosphofructokinase directly inhibits ATP synthase. D. If ATP levels are high, this provides a mechanism to directly inhibit the electron transport chain, thus preventing the formation of a proton gradient in the intermembrane space of mitochondria.
B
Tacrolimus (FK-506) is a drug that inhibits an enzyme called calcineurin. Calcineurin is a protein phosphatase. This is an enzyme that dephosphorylates (removes phosphate groups from) proteins. When added to cells, tacrolimus can inhibit the dephosphorylation of a protein called NFAT, but it cannot prevent the dephosphorylation of a protein called CDK1. What is the most likely explanation for this finding? A. Calcineurin requires an additional cofactor to dephosphorylate NFAT B. NFAT is a substrate of calcineurin, but CDK1 is not C. Tacrolimus is a competitive inhibitor of calcineurin for NFAT, but not for CDK1 D. Tacrolimus changes the optimum pH for calcineurin
B
The accommodation of the very long DNA strands that are part of a chromosome into the limited space of the nucleus is achieved by coiling the DNA around beads of histones into repeating subunits. These DNA-wrapped histones are called: A. Solenoids B. Nucleosomes C. Chromatin loops D. Rosettes
B
The amount of energy available to do work is called: A. activation energy B. free energy C. kinetic energy D. potential energy
B
The two copies of each type of chromosome found in normal somatic (body) cells in an organism, throughout the cell cycle, are called: A. Sister chromatids B. Homologous chromosomes C. Daughter chromosomes D. Kinetochores
B
This protein or protein complex functions in the cell to stop cell division if the cell has experienced extensive DNA damage: A. APC/C B. p53 C. FtsZ D. Condensin
B
What are the products of one turn of the Krebs cycle? A. 1 CO2, 2 NADH, 1 FADH2, 1 ATP B. 2 CO2, 3 NADH, 1 FADH2, 1 ATP C. 2 CO2, 6 NADH, 2 FADH2, 2 ATP D. 4 CO2, 6 NADH, 2 FADH2, 2 ATP E. 4 CO2, 12 NADH, 4 FADH2, 4 ATP
B
What happens during Anaphase B? A. Kinetochores are pulled toward the poles. B. The spindle poles move apart. C. The spindle apparatus disassembles. D. The nuclear envelope reforms. E. The APC/C gets activated for the first time.
B
What important metabolic intermediate does not cross the inner membrane of the mitochondria? A. ATP B. Acetyl-CoA C. Pyruvate D. Oxygen
B
What is different about the way that NADH and FADH2 donate electrons to the electron transport chain? A. NADH is oxidized and FADH2 is reduced. B. NADH contributes its electrons to the first transmembrane complex in the electron transport chain and FADH2 contributes its electrons after the first transmembrane complex. C. More protons are transported into the intermembrane space of the mitochondria in response to one molecule of FADH2 as compared to the number of protons transported in response to one molecule of NADH. D. The electrons from NADH ultimately go on to reduce oxygen to generate water, whereas the electrons from FADH2 are used to reduce pyruvate to lactate.
B
What would be the ATP yield for a molecule that is catabolized to form one molecule of pyruvate in a eukaryotic cell? A. 10 ATP B. 12.5 ATP C. 25 ATP D. 30 ATP E. 32 ATP
B
What would you expect to happen if the anaphase-promoting complex/cyclosome (APC/C) failed to ubiquitinate securin? A. The cohesin complex will be destroyed, and the cell will remain in metaphase. B. The cohesin complex will persist, preventing the cell from entering anaphase. C. Separase will be marked for degradation by securin, preventing the cell from entering anaphase. D. Securin will remain intact and therefore will degrade cohesin, allowing the cell to enter anaphase.
B
Why is it so important that all of the chromosomes align on the metaphase plate during metaphase? A. This is the only place in the cell where the cyclins and Cdks are located. B. If they cannot, it suggests that they aren't properly attached to the spindle microtubules, and thus won't separate properly during anaphase. C. This is the location where the chromosomes can become attached to the spindle microtubules. D. This allows asters to form. E. This allows sister chromatids to form.
B
You are studying cell cycle progression in yeast cells. If you could prevent cdc2 from associating with the mitotic cyclin, the cells would: A. arrest in G1. B. arrest in G2. C. arrest in S. D. arrest in prometaphase. E. arrest in metaphase.
B
You return home to find that your baby brother has scattered his toy trains and trucks all over the floor of your room. As you begin to pick up the toys and put them away, you realize that even though he is just a baby, he has clearly mastered: A. the first law of thermodynamics. B. the second law of thermodynamics. C. potential energy. D. free energy.
B
How many oxidation reactions occur during the Krebs cycle? A. 1 B. 2 C. 3 D. 5 E. 8
C
If ATP synthase had a mutation in the F1 complex portion of the protein, what function of ATP synthase would most likely be affected? A. The rotation of the rotor. B. The flow of protons through the channel. C. The conversion of ADP and Pi to ATP. D. The insertion of the enzyme into the membrane.
C
A molecule that closely resembles the shape of a substrate for an enzyme would most likely serve as a: A. noncompetitive inhibitor B. allosteric inhibitor C. competitive inhibitor D. allosteric activator
C
AMP-activated protein kinase (AMPK) is an enzyme that is activated by high levels of AMP in cells. If levels of AMP are high in cells, that means that levels of ATP are low. Once active, AMPK activates catabolic pathways and inhibits anabolic pathways in the cell. Why do you think that is the case? Choose the answer that best explains the role of AMPK. A. High levels of AMP indicate that there is a high amount of energy stored in the cell, thus activating catabolic pathways and inhibiting anabolic pathways are mechanisms to use stored energy. B. By inhibiting anabolic pathways, AMPK provides a mechanism to generate heat for the cell, which is important if AMP levels are high in the cell. C. By activating catabolic pathways, AMPK provides a mechanism to activate exergonic pathways, which is important if AMP levels are high in the cell. D. Activating catabolic pathways and inhibiting anabolic pathways will ultimately lead to higher consumption of ATP, which is important if AMP levels are high in the cell.
C
Cytochromes contain a heme group similar to that in hemoglobin. The iron atom (Fe) in the center of the group can be oxidized and reduced. If someone was suffering from iron deficiency anemia, what stage of cellular respiration would be most affected? A. Glycolysis B. The Krebs cycle C. The electron transport chain D. Fermentation
C
Glucose is converted into glucose 6-phosphate by hexokinase. Glucose 6-phosphate then serves as the substrate for the enzyme phosphoglucose isomerase, which converts this reactant into fructose 6-phosphate. Fructose 6-phosphate serves as the substrate for phosphofructokinase, which converts fructose 6-phosphate into fructose 1,6-bisphosphate. Based on the information provided, this is an example of what? A. Feedback inhibition B. Allosteric regulation C. A metabolic pathway D. Enzyme inhibition
C
In aerobic respiration, chemiosmotic generation of ATP is driven by: A. Pi transfer through the plasma membrane. B. the Na+/K+ pump. C. a difference in H+ concentration on the two sides of the inner mitochondrial membrane. D. osmosis of macromolecules. E. large quantities of ADP.
C
In an enzyme-catalyzed reaction, the reactant is called the: A. coenzyme B. catalyst C. substrate D. product
C
In the reaction catalyzed by aconitase, the conversion of citrate to isocitrate is inhibited by fluoroacetate. Fluoroacetate is used as a pesticide. Why is this an effective pesticide? A. It inhibits glycolysis B. It inhibits pyruvate oxidation C. It inhibits the Krebs cycle D. It inhibits the electron transport chain E. It inhibits ATP synthase
C
In the reaction: C4H6O4 + FAD C4H4O4 + FADH2, what type of reaction took place to remove the protons from C4H6O4? A. Decarboxylation B. Reduction C. Dehydrogenation D. Oxidation
C
Many metabolic pathways are ultimately concerned with ATP; either with the generation of ATP, or with the requirement of ATP for that pathway to function. Why is ATP so important to metabolism? A. Hydrolysis of ATP is used to drive exergonic reactions B. Hydrolysis of the bond between adenine and ribose in ATP is commonly used to release energy that can be used to drive other cellular reactions C. The phosphate groups of ATP are held together by unstable bonds that can be broken to release energy D. ATP is a protein that serves as the energy currency of cells
C
Regardless of the electron or hydrogen acceptor used, one of the products of fermentation is always: A. ADP B. ATP C. NAD+ D. pyruvate E. alcohol
C
The point of connection between two sister chromatids, before anaphase II of meiosis separates them, is called the A. centriole B. kinetochore. C. centromere. D. spindle apparatus. E. centrosome.
C
This stage of the cell cycle is characterized by growth and it contains a checkpoint to verify that all of the DNA has been replicated prior to mitosis. A. G1 B. S C. G2 D. Mitosis E. Cytokinesis
C
To form NADH from NAD+, two electrons and a proton are removed from an organic molecule. What term best describes the reaction in which electrons and a proton are removed from an organic molecule? A. Condensation B. Reduction C. Dehydrogenation D. Decarboxylation E. Isomerization
C
Under standard conditions, ATP can release for every molecule converted to ADP A. less than 1 cal of energy. B. 1 to 2 cal of energy. C. 7.3 Kcal of energy. D. different amounts of energy depending on the cell.
C
What is separase? A. A protein that marks a protein called securin for destruction. B. A protein that is part of the cohesin complex. C. A protein that destroys cohesin through its protease activity. D. A protein that targets the mitotic cyclin for degradation
C
When substrate-level phosphorylation occurs, it means that: A. NAD+ is converted into NADH. B. ATP is converted into ADP plus a phosphate group. C. ADP is converted into ATP by the addition of a phosphate group. D. NADH is converted into NAD+ plus a proton.
C
While conducting an experiment, you realize that a competitive inhibitor was interfering with your reaction. How could you overcome this problem? A. Add a non-competitive inhibitor to the reaction. B. Add a cofactor to the reaction. C. Increase the concentration of the correct substrate in the reaction. D. Add an allosteric activator to the reaction.
C
You decide to go on vacation in the mountains, where you are staying in a cabin. Unfortunately, when you turn on the water in the cabin you smell hydrogen sulfide (H2S) gas. After some research, you find out that the H2S may be due to the presence of sulfur bacteria living in your pipes. What molecule do these bacteria use as an electron acceptor? A. O2 B. H20 C. SO4 D. H2S
C
A somatic cell from a corn plant normally contains 20 chromosomes. How many sister chromatids would that cell contain during G2 of the cell cycle? A. 0 B. 10 C. 20 D. 40
D
Arsenic poisoning can lead to organ failure and death. Though arsenic can inhibit or interfere with a number of cellular enzymes, arsenic poisoning is thought to be mainly due to indirect inhibition of enzymes involved in both pyruvate oxidation and the Krebs cycle. As a result, this compound must be able to enter what cellular compartment? A. The cytoplasm B. The nucleus C. The intermembrane space of the mitochondria D. The mitochondrial matrix E. The endoplasmic reticulum
D
As a forensic pathologist, you have just completed an autopsy of a poisoning victim. After a thorough examination, you conclude that the victim died of cyanide poisoning. You know that cyanide binds to the cytochrome oxidase complex, and therefore list the official cause of death as suffocation due to cyanide exposure. However, if you wanted to provide a more technical explanation as to the cause of death, what process was specifically inhibited directly by cyanide? A. The reduction of NAD+ B. The oxidation of FADH2 C. All proton pumping into the intermembrane space D. The formation of water from oxygen E. ATP synthesis
D
At what checkpoint(s) does the cell arrest in response to DNA damage? A. G1/S B. G2/M C. spindle D. G1/S and G2/M E. G2/M and spindle
D
Cardiac muscle cells need to generate significant amounts of ATP to allow for constant contractile activity. As a result, they primarily depend upon beta-oxidation of fatty acids, which has a higher energy yield than the catabolism of glucose. What would be the ATP yield for beta-oxidation of a hypothetical 10-carbon fatty acid? A. 32 ATP B. 35 ATP C. 50 ATP D. 62 ATP E. 65 ATP
D
What happens to the oxygen that is used in cellular respiration? A. It is converted to carbon dioxide B. It is used to make glucose C. It is used to make Krebs cycle intermediates D. It is reduced to form water E. It is converted to acetyl-CoA
D
Does ADP contain the capacity to provide energy for the cell? A. No. ADP does not contain any bonds that can be broken to provide energy for the cell. B. Yes. ADP has the same capacity to provide energy for the cell as ATP. C. Yes. Cleaving the bond between the ribose sugar and the two phosphate groups can provide energy for the cell. D. Yes. Cleaving the bond between the terminal phosphate and the phosphate attached to the ribose sugar can provide energy for the cell.
D
Following S phase, a human cell would have how many pairs of sister chromatids and individual DNA molecules? A. 23 pairs of sister chromatids and 46 individual DNA molecules B. 23 pairs of sister chromatids and 92 individual DNA molecules C. 46 pairs of sister chromatids and 46 individual DNA molecules D. 46 pairs of sister chromatids and 92 individual DNA molecules E. 46 pairs of sister chromatids and 184 individual DNA molecules
D
Glucose is broken down through cellular respiration, which involves a large number of chemical reactions. At the end of the cellular respiration process, a large number of ATP molecules are generated, but yet, not all of the possible energy that is contained in a molecule of glucose can be harnessed through these chemical reactions to generate ATP. In other words, during cellular respiration, not all of the energy that is contained in a molecule of glucose is converted into the energy stored in ATP. What happened to the remaining energy? A. It is destroyed B. It is used to drive exergonic reactions C. It is donated to molecules in the cellular respiration process to reduce them D. It is lost as heat
D
If the G of a reaction was -31.45 kJoules, you would know that: A. the products have more free energy than the reactants. B. the reaction requires an energy input of 31.45 kJoules to proceed. C. the reaction most likely leads to development of a more ordered system. D. the reaction is spontaneous.
D
If you take into account the amount of ATP generated by ATP synthase per molecule of NADH and per molecule of FADH2 produced, and the number of ATP molecules produced by substrate-level phosphorylation, what is the predicted energy yield of the Krebs cycle, per molecule of glucose in eukaryotic cells? A. 1 ATP B. 2 ATP C. 10 ATP D. 20 ATP E. 30 ATP
D
In order to lose weight and reduce body fat, a friend of yours has decided to eliminate all fat from his diet, while consuming unrestricted amounts of carbohydrates. What do you think of this idea? A. It is a good idea, because if your friend doesn't eat any fat, he cannot store any additional fat. B. It is a bad idea, because consumption of fat is required to provide cofactors for the electron transport chain. C. It is a good idea, because under conditions where ATP levels are low in cells, carbohydrates will be stored, and fat stores will be catabolized via beta-oxidation to generate energy. D. It is a bad idea, because if ATP levels are high in cells, excess acetyl-CoA from the metabolism of carbohydrates can be used for fatty acid synthesis.
D
It is thought that the oldest stage of cellular respiration from an evolutionary perspective is: A. The Krebs cycle B. The electron transport chain C. Fermentation D. Glycolysis
D
Kinases are enzymes that can phosphorylate (transfer phosphate groups onto) macromolecules such as proteins. A particular kinase, Kinase 1 is known to promote cell division. It promotes cell division by phosphorylating Protein X. Phosphorylation of Protein X activates Protein X. Once activated, Protein X stimulates the production of other proteins such as Protein Y and Z that directly promote cell division. In order to function, Kinase 1 requires the presence of Metal A. However, in the presence of Protein A, Kinase 1 is nonfunctional. From the description, what is considered a cofactor of Kinase 1? A. Protein X B. Protein Y C. Protein Z D. Metal A E. Protein A
D
Many of the antiviral drugs currently used to treat HIV/AIDS also interfere with an enzyme that helps mitochondria multiply. Treatment can therefore result in a decrease in the number of mitochondria found in certain tissues. Given this information, what might you expect to see in patients treated with antiviral drugs? A. An increase in oxidative phosphorylation B. An increase in phosphofructokinase activity C. An increase in NADH dehydrogenase activity D. An increase in lactic acid levels
D
Phosphofructokinase (PFK) is an enzyme that converts fructose 6-phosphate to fructose 1,6-bisphosphate, by adding a phosphate group. This is the first committed step of the metabolic pathway of glycolysis, and thus it is very tightly regulated. AMP binds to PFK at a site distinct from the binding site for fructose 6-phosphate, and stimulates the formation of fructose 1,6-bisphosphate. ATP binds to PFK at a site distinct from the binding site for fructose 6-phosphate, and inhibits the formation of fructose 1,6-bisphosphate. There are other regulators of this enzyme as well. What is the role of AMP in this example? A. Competitive inhibitor B. Noncompetitive inhibitor C. Allosteric inhibitor D. Allosteric activator E. Catalyst
D
The Krebs cycle occurs in the mitochondria. There are nine biochemical reactions involved in the Krebs cycle, and they are highly ordered. Select the correct order from the following choices. (Note: These are abbreviated and do not show NAD, ADP, ATP, or FAD.) A. acetyl-CoA joins the Kreb cycle and unites with oxaloacetate forming citrate which forms beta-ketoglutarate which forms succinyl-CoA which forms succinate which forms fumarate which forms malate which forms oxaloacetate B. acetyl-CoA joins the Kreb cycle and unites with oxaloacetate forming citrate which forms alpha-ketoglutarate which forms succinyl-CoA which forms succinate which forms malate which forms fumarate which forms oxaloacetate C. acetyl-CoA joins the Kreb cycle and unites with oxaloacetate which forms alpha-ketoglutarate forming citrate which forms succinyl-CoA which forms succinate which forms fumarate which forms malate which forms oxaloacetate D. acetyl-CoA joins the Kreb cycle and unites with oxaloacetate forming citrate which forms alpha-ketoglutarate which forms succinyl-CoA which forms succinate which forms fumarate which forms malate which forms oxaloacetate
D
The energy released in the mitochondrial electron transport chain is used to transport protons where? A. Into the mitochondrial matrix B. Into the cytoplasm C. Into the endoplasmic reticulum D. Into the intermembrane space of the mitochondria E. Into the nucleus
D
The number of chromosomes characteristic of diploid eukaryotic cells, in general: A. is 46. B. can be predicted by the size of the organism. C. changes as each organism grows and ages. D. varies considerably from 2 to over 1000 in different species.
D
Your friend is having difficulty keeping track of the energy flow from glucose through glycolysis, the Krebs cycle and electron transport. Your best advice would be to: A. follow ATP production. B. follow the protons. C. follow NAD+ production. D. follow the electrons.
D
If a drug that inhibited transport from the trans face of the Golgi was applied to plant cells, which stage of the cell cycle would be directly affected? A. G2 B. S C. Metaphase D. Anaphase E. Cytokinesis
E
The equation for cellular respiration is: C6H12O6 + 6O2 6CO2 + 6H2O. At what specific point in the cellular respiration process has glucose been broken down completely from a six carbon molecule to 6 molecules of CO2? A. During the priming reactions in glycolysis B. During the oxidation and ATP formation reactions in glycolysis C. During pyruvate oxidation D. During the condensation reaction in the Krebs cycle E. During the second oxidation in the Krebs cycle
E
The zygote has A. one copy of each chromosome. B. one full haploid complement of chromosomes. C. chromosomes identical to those of a sperm cell. D. chromosomes identical to those of an egg cell. E. two copies of each chromosome.
E
When amino acids are degraded in cells, into what intermediate(s) of the aerobic respiration process are the carbon skeletons of amino acids primarily converted? A. Pyruvate B. Acetyl-CoA C. Krebs cycle intermediates D. Pyruvate and acetyl-CoA E. Pyruvate and Krebs cycle intermediates
E