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55 terms

Exam 3

Consider the following reaction: C6H12O6 (glucose) + 6O2 → 6 CO2 + 6H2O. Where is most of the water in this reaction produced?
electron transport chain
__________ generates the MOST ATP due to its earlier point of entry (Complex I of the ETC) in the electron transport chain
Cells that utilize ________ as the terminal electron acceptor in the electron transport chain are said to undergo _________ respiration.
oxygen; aerobic
In a eukaryotic cell, how much ATP is produced from one glucose molecule moving through a complete cycle of glycolysis, pyruvate processing, Kreb's cycle and the electron transport chain?
30 ATP and 32 ATP

(Both A and B)
In ________ fat mitochondria; the energy from the proton motive force generated from the electron transport chain is released as heat instead of utilization in ATP production.
During meiosis, Sister chromatids separate during ________.
anaphase II.
What is a major difference between meiosis II and mitosis?
Meiosis II takes place in a haploid cell, while mitosis takes place in diploid cells.
If a plant cell wanted to augment (increase) its ATP production, what type of energy production pathway would it choose?
cyclic photophosphorylation
Early detection is the key to successful treatment of most cancers. Why?
Cells from the primary tumor are less likely to have started secondary tumors
When an electron is excited by the absorption of light energy, and then "falls" back to the ground state without transferring the energy to another molecule, the absorbed energy is released as light and heat. This light energy is specifically called__________. When the energy is transferred to another pigment molecule in the antennae complex exciting that pigment's electrons, the energy exchange is referred to as _____________.
fluorescence; resonance
If meiosis produces haploid cells, how is the diploid number restored for those organisms that spend most of their life cycle in the diploid state?
The energy of electron transport serves to move (translocate) protons to the outer mitochondrial compartment. How does this help the mitochondrion to produce energy?
The translocation of protons sets up the electrochemical gradient that drives ATP synthesis in the mitochondria.
The chemiosmotic hypothesis is an important key to understanding general metabolism because ________.
it explains how ATP is synthesized by a proton motive force.
How many cycles of β-oxidation would you expect a 10 carbon fatty acid to undergo?
The electrons of photosystem II are excited and transferred to electron carriers. From which molecule or structure do the photosystem II replacement electrons come?
If a cell has accumulated DNA damage, it is unlikely to ________. (Hint: think about the steps in interphase)
pass the G2 checkpoint.
Regulatory proteins that serve to prevent a cell from entering the S phase under conditions of DNA damage are also known as ________.
tumor suppressors.
For cells to divide more rapidly, increased production would likely be required of each of the following proteins
except ________. (Hint: Which one is a tumor suppressor?)
The light-independent reactions of plants function to make organic molecules using carbon dioxide as a carbon source. What is the electron source that helps reduce carbon dioxide to sugars and other organic molecules?
Photorespiration is ________.
a process involving the addition of oxygen to ribulose-1,5-bisphosphate and the formation of the products 3-phosphoglycerate and 2-phosphoglycolate, decreasing the ability of the plant to reduce CO2 to sugar molecules
Which of the following organisms would be the most affected by a mutation that occurred at a single locus or allele on one chromosome?
a bacterium
What is a major difference between mitosis and meiosis I?
Sister chromatids separate in mitosis, and homologues separate in meiosis I.
A proton ionophore, a molecule that forms an artificial channel allowing hydrogen ions to cross membranes, will _____ the concentration of ATP in a cell. HINT: Consider what would happen if the concentrations of hydrogen ions on both sides of the inner mitochondrial membrane were equal.
The biochemical outcome of the activity of photosystem I is to:
reduce NADP+
A certain species of animal has six pairs of chromosomes. How many individual chromosomes do the nuclei of these animal's somatic cells have during G2 phase?
Mitotic spindle fibers are composed of what cellular structures?
Taxol is a drug that stabilizes microtubules in animal cells and prevents them from depolymerizing. Consequently cells treated with Taxol fail to complete mitosis. What event during the subphases of mitosis is most likely to be inhibited by this drug?
movement of the sister chromatids to their respective poles
Which of the following statements concerning crossing over is true?
Chromosomes that result from crossing over have a mixture of maternal and paternal alleles
The consequence of E2F inactivation (i.e. complexed with the Rb protein) is that:
cells would be unable to enter the S phase
As electrons are passed through the system of electron carriers associated with photosystem II, they lose energy. What happens to this energy?
It is used to establish and maintain a proton gradient.
Genetic recombination (the mixing of paternal/maternal chromosomes) takes place in which of the following processes?
crossing over
Under which conditions will the Krebs cycle be activated?
high levels of AMP and ADP
CAM plants function using crassulacean acid metabolism. Like C4 plants, CAM plants provide a preparatory step for the Calvin cycle. CAM plants are found in hot, dry environments; to prevent dessication, they keep their stomata closed during the day. They take in carbon dioxide at night while stomata are open. To increase the concentration of carbon dioxide available to the enzyme rubisco and minimize the degree of photorespiration, the CAM plants carboxylate ________.
organic acids
Once researchers understood that chromosomes are moved by the spindle microtubules, the next question they wanted to answer is how the microtubules function to bring about this process. They used fluorescent labels to make the chromosomes and the microtubular structures fluoresce. When anaphase began (centromeres split), they photobleached a section of microtubules. As chromosomes moved toward the poles of the daughter cells, the photobleached sections of the microtubules remained stationary. This result suggests that ________.
the microtubules elongate and shorten at their kinetochore (the "crown" apparatus attached to each sister chromatid) end.
The Z scheme models the interaction between photosystem I and photosystem II. What does the "Z" represent?
the changes that occur in potential energy of electrons as they move through the two photosystems.
The first gap in the cell cycle (G1) corresponds to ________.
normal growth and functioning.
The diploid number of a roundworm species is 4. You have a male and a female roundworm that are planning a family. Assuming there is no crossover, and random segregation of homologues during meiosis, how many different possible combinations of chromosomes might there be in the offspring?
Metaphase occurs prior to the splitting of centromeres. It is characterized by ________.
aligning of chromosomes on the equator.
FtsZ is a bacterial cytoskeletal protein that forms a contractile ring involved in bacterial cytokinesis. Its function is analogous to _____.
the cleavage furrow of eukaryotic animal cells
Nerve cells lose their ability to undergo mitosis. Instead, they are permanently stuck in ________.
Myosin is a motor protein involved in animal cell cytokinesis. It binds to ATP or ADP, causing the myosin to move with respect to actin. What is the effect of the interaction between myosin and actin?
The cleavage furrow deepens.
In the process of chromosome separation, how do microtubules maintain contact with the kinetochores and shorten at the same time?
Motor proteins move chromosomes down the microtubular structures of the mitotic spindle.
Following glycolysis and the Krebs cycle, but before the electron transport chain and oxidative phosphorylation, the carbon skeleton of glucose has been broken down to CO2 with some net gain of ATP. Most of the energy from the original glucose molecule at that point in the process, however, is in the form of _____.
Once a cell completes mitosis, molecular division triggers must be turned off. What happens to MPF during mitosis?
Cyclin is degraded; the concentration of cyclin-dependent kinase remains unchanged, but without cyclin, MPF is not formed.
If you were to add one of the eight Krebs cycle intermediates to the culture medium of yeast growing in the laboratory, what do you think would happen to their rates of ATP and carbon dioxide production?
The rates of ATP production and carbon dioxide production would both increase.
Stress that results in the damage of DNA activates the p53 protein, which in turn activates DNA repair pathways. However, if the DNA is unable to be repaired correctly, what other event can p53 induce in the cell?
The cells that produce sperm in humans contain 46 chromosomes. If one of these cells undergoes meiosis to form sperm cells, and chromosomal nondisjunction occurs in chromosome 22 during meiosis I, what is the chromosome number in each of the resulting sperm cells?
24, 24, 22 and 22
The M-phase checkpoint is designed to make sure all chromosomes are attached to the mitotic spindle. If this fails to happen, in which stage of mitosis would the cells be most likely to arrest?
Nondisjuction of chromosomes results in _______________.
Engelmann's experiment with Spyrogyra ( a filamentous algae) involved exposing these photosynthetic organisms to a prism, which divided sunlight into the individual components of the visible light spectrum. Aerobic bacteria grew best along the parts of the algae that were exposed to red and blue light. Why?
In these two areas photosynthesis was occuring and oxygen was produced.
American Idol called and your audition was a success. You quickly run up four flights of stairs to schedule a make-up quiz with your professor, and feel an odd burning sensation in your legs, which you haven't felt since you became addicted to text messaging during Bio1100. The burning results from a reaction that regenerates ___________, which is required to proceed into the ______________ of glycolysis.
NAD+; energy payoff phase
American Idol called and your audition was a success. You quickly run up four flights of stairs to schedule a make-up quiz with your professor, and feel an odd burning sensation in your legs, which you haven't felt since you became addicted to text messaging during Bio1100. The eventual soreness that you feel in your legs results from a buildup of ________ _______, and this buildup is a result of your muscle cells undergoing a metabolic reaction called _____________.
lactic acid; fermentation
When a sperm and egg combine, the resulting embryo has _____. HINT: What is the ploidy of sperm and egg cells?
half of the mother's genetic information and half of the father's
Why are fermentation reactions important for cells?
They regenerate NAD+ so that glycolysis can continue.
What is the final result of mitosis?
genetically identical 2n somatic cells