BIOL113 Practice Set 1 lectures 1-7

docx

School

Binghamton University *

*We aren’t endorsed by this school

Course

BIOL-113

Subject

Biology

Date

Feb 20, 2024

Type

docx

Pages

Uploaded by ColonelRiver2701

While completing this practice set, mimic the testing environment as much as possible. Check your answers with the key on the last pages only after completing the entire set. Refer to the exam prep videos for more information on how to make the most of the practice sets. Riboflavin (also called vitamin B2) is an essential vitamin that the human body cannot synthesize on its own but must ingest. When a healthy person ingests riboflavin in their food, it travels through the stomach and into the small intestine. There, the riboflavin is absorbed into the blood vessels that surround the small intestine, moving through the riboflavin cotransporter protein (RFVT3). Sodium, Na+, moves in the same direction also through RFVT3 from a low concentration to a high concentration in the blood vessels. Once absorbed by the cells of the body, riboflavin acts as a coenzyme, which means it helps enzymes perform chemical reactions. If RFVT3 cotransporters become mutated, riboflavin cannot be sufficiently absorbed so enzymes in cells all over the body are not able to perform many chemical reactions. Thus, a condition called riboflavin transporter deficiency neuronopathy (neuron degradation) ensues. People suffering from this condition have neurological symptoms such as muscle weakness in the face and limbs and hearing loss. 1. Celeste is diagnosed with riboflavin transporter deficiency neuronopathy. She reads about the condition on the website for the National Organization for Rare Diseases, rarediseases.org. This is her first time encountering this organization. What is one way she can determine if this organization is a reliable source of scientific information about her condition? a) The website includes a patient assistance program, which helps patients find highly rated doctors where they live. b) The website sites (and links to) peer reviewed scientific journal articles in their summaries and recommendations. c) The website includes testimonials from patients that have been participating in a clinical trial for a new treatment. d) The website describes in great scientific detail the cellular mechanism which causes the condition and its symptoms. 2. Celeste is interested in participating in a clinical trial that uses genetic engineering technology to fix the SLC52A2 gene, which codes for the riboflavin cotransporter protein (RFVT3). This particular genetic engineering method was first used to cure Sickle Cell Anemia several years ago. The primary investigators of this clinical trial are using the same method. This demonstrates which strength of science? a) Conclusions change based on new evidence. b) Scientists use each other’s work. c) Scientific consensus is the result of testing the same hypothesis many times. d) Experiments are designed to be blind and/or double blind. 3. Genetic engineering is a relatively new medical technique that is being used to attempt to cure genetic diseases. Sickle Cell Anemia has indeed been cured by using this technique and other

research shows promise for other genetic diseases. As the research mounts for the ability of genetic engineering to cure genetic diseases the scientific community gets closer to a) A scientific consensus b) A scientific conclusion c) Controversy in the general public d) Acceptance in the general public 4. While reading about the clinical trial, Celeste clicks on and reads one of the peer reviewed scientific articles that the clinical trial is based on. In this experiment, the authors test the genetic engineering method on mice that have the condition. The authors expect that the genetic engineering treatment will improve riboflavin transport from the small intestine to the blood vessel. Which of the following is (a) prediction(s) for this experiment? Select all. a) The treatment will increase the concentration of riboflavin in the blood. b) After one injection of the treatment over 50% of mice will show statistically improved facial muscle tone. c) After one injection of the treatment over 50% of mice will show statistically improved facial muscle tone, measured precisely in cm by the facial grading system, after 15 days and after 30 days. d) After an injection of the treatment on day 1 and again on day 2, over 85% of mice will have a statistically increased concentration of riboflavin in blood samples after 15, 30, and 60 days. 5. There are 30 randomly chosen 25-day-old female mice in the experimental group and 30 in the negative control group. All the mice have nonfunctioning riboflavin cotransporter proteins. On day 0 of the experiment all mice have their blood drawn and the concentration of riboflavin is measured. In the experimental treatment the mice are given an injection of the genetic treatment on day 1 and again on day 2. On day 15, 30 and 60 blood is taken and riboflavin concentration is measured. What is the most scientifically robust procedure for the negative control group? a) Give a supplement of riboflavin on day 1 and day 2. Blood drawn on day 15, 30 and 60. b) Give a supplement of riboflavin on day 1 and day 2. Blood not drawn. c) Injection without treatment on day 1 and day 2. Blood not drawn. d) No injection. Blood drawn on day 15, 30 and 60. e) Injection without treatment on day 1 and day 2. Blood drawn on day 15, 30 and 60. 6. Below is a graphical depiction of the results of the experiment. Here is a series of select individual measurements (not all measurements).

a b c d 560 600 150 100 550 495 160 140 576 550 138 200 550 527 160 170 Which of these series of individual measurements is most likely to be taken from the experimental treatment on day 15? 7. Hypothetically, if between 31 and 60 days, 14 mice in the control group died and 1 mouse in the experimental group died, this change in sample size would most likely affect which feature of the results at 60 days? a) Scientific consensus b) Standard deviation c) Statistical conclusion d) Standard error 8. What statistical conclusion can be made from these results? a) Reject the null hypothesis. There is a significant statistical difference between day 0 and day 15, 30 and 60. The genetic treatment increases riboflavin concentration in the blood. b) Fail to reject the null hypothesis. There is a significant statistical difference between day 0 and day 15, 30 and 60. The genetic treatment increases riboflavin concentration in the blood. c) Reject the null hypothesis. There is not a significant statistical difference between the control treatment and the experimental treatment. The genetic treatment has no effect on the riboflavin concentration in the blood. d) Fail to reject the null hypothesis. There is not a significant statistical difference between the control treatment and the experimental treatment. The genetic treatment has no effect on riboflavin concentration in the blood. e) Reject the null hypothesis. There is a significant statistical difference between the control treatment and the experimental treatment. The genetic treatment increases riboflavin concentration in the blood. 9. The strain of mice used in this experiment are derived from a population of Tundra mice that evolved in the cold climate of northern Canada. Tundra mice have more ______ phospholipids in

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

the cell membranes of the cell that make up their feet compared to rainforest mice that evolved in a warm climate. Which species would have greater (faster) permeability to CO2? a) Saturated. Permeability to CO2 would be equal. b) Saturated. Tundra mice would have greater permeability to CO2. c) Unsaturated. Permeability to CO2 would be equal. d) Unsaturated. Rainforest mice would have greater permeability to CO2. 10. In addition to neurological symptoms, patients with riboflavin transporter deficiency neuronopathy also suffer from a weakened immune system. Celeste experiences this as a series of strep throat infections that stop responding to antibiotics. Strep throat is caused by the group A Streptococcus bacteria species. The initial mutation which conferred resistance to antibiotics arose ______. a) Randomly, due to a mutation during reproduction. b) Randomly, due to the application of antibiotics. c) Via natural selection. The bacteria detected the antibiotic and needed to develop resistance. d) Via natural selection. The antibiotic killed all the susceptible bacterial cells, leaving only resistance cells. 11. The entire population of Streptococcus bacteria in Celeste’s throat eventually developing antibiotic resistance occurred ______. a) Randomly, due to a mutation during reproduction. b) Randomly, due to the application of antibiotics. c) Via natural selection. The bacteria detected the antibiotic and needed to develop resistance. d) Via natural selection. The antibiotic killed all the susceptible bacterial cells, leaving only resistance cells. 12. The genetic engineering treatment Celeste reads about is composed of several chemical structures including an N bound to an O. N What kind of bond will N and O make? B C N O F Al Si P S Cl a) Ionic bond, where electrons are transferred completely. b) Polar covalent bond, where electrons are shared unequally. c) Nonpolar covalent bond, where electrons are shared equally. d) Polar covalent bond, where electrons are shared equally. e) Nonpolar covalent bond, where electrons are unequally.

13. Remember that normally, ingested riboflavin is absorbed into the blood vessels that surround the small intestine, moving through the riboflavin cotransporter protein (RFVT3). Sodium, Na+, moves in the same direction also through RFVT3 from a low concentration to a high concentration in the blood vessels. What kind of membrane transport is RFVT3 operating? a) Simple diffusion b) Facilitated diffusion c) Primary active transport d) Secondary active transport 14. Why does Na+ require transport through a protein channel to get out of the small intestine cell? a) Because it is highly charged and will get stuck interacting with the polar heads of the phospholipids. b) Because it is not charged and will be attracted to the nonpolar tails of the phospholipids. c) Because it is a polar covalent bond and will be repelled by the polar heads of the phospholipids. d) Because it is a nonpolar covalent bond and will get stuck interacting with the polar heads of the phospholipids. 15. The study that Celeste reads which tests the efficacy of the genetic treatment on mice cites a different paper that tested the same treatment directly on faulty RFVT3 cotransporters that were embedded in artificial cells and suspended in beakers of water. Inside of the artificial cell represented the small intestine and the water represented the blood vessels. The authors began the experiment with starting osmotic concentrations of riboflavin and Na+ which mimic the operation of a properly functioning RFVT3 cotransporter. Considering only the concentration of Na+, inside the artificial cell is __________ compared to the surrounding water. a) Isotonic b) Hyperosmotic c) Hypoosmotic 16. Half of the flasks in the experiment receive the genetic treatment and the other half does not. Imagine that in the negative control flasks, Na+ is added to the experiment according to your answer to the previous question. Riboflavin is not added. Aquaporins are present. Where will water immediately move? a) Most will move into the surrounding water. None will move into the cell. b) Most will move into the surrounding water. Alittle will move into the cell. c) Most will move into the artificial cell. None will move out of the cell. d) Most will move into the artificial cell. A little will move out of the cell. 17. In a healthy individual, when the level of riboflavin in the small intestine drops close to zero, the RFVT3s degrade. Only when riboflavin is present again do new RFVT3s form. For a short time during their formation, the new RFVT3 are shaped as a spiraling alpha helix. Which level of structure does this refer to? At this level of structure can RFVT3 function to move sodium and riboflavin? a) Primary; no b) Secondary; no c) Secondary; yes d) Tertiary; no

e) Tertiary; yes 18. Riboflavin transporter deficiency neuronopathy is usually caused by a RFVT3 that is mutated because of a genetic mutation. However, sometimes it is caused by a RFVT3 that is nonfunctional because the environmental toxin HYU is acting as an inhibitor which changes it’s shape. What type of inhibition is this? What is its immediate effect? a) Cleavage of peptide bonds; neither HYU nor RFVT3 can bind. b) Competitive; riboflavin is physically and directly blocked from binding RFVT3. c) Competitive; HYU binds somewhere other than the active site. Riboflavin can’t bind. d) Allosteric; riboflavin is physically and blocked from binding RFVT3. e) Allosteric; HYU binds somewhere other than the active site. Riboflavin can’t bind. 19. Remember that riboflavin acts as a coenzyme for many enzymes in the cell. This means that it is necessary for the enzyme functioning. Two such enzymes are called glutathione synthetase alpha and beta. Glutathione synthetase alpha catalyzes the conversion of L-glutamate and cysteine to gamma-glutamylcysteine. Then glutathione synthetase beta binds gamma-glutamylcysteine together with a glycine to make glutathione (an antioxidant). These steps are outlined in the diagram below. If the primary structure of Glutathione synthetase alpha is severed, the concentration of which molecule will immediately increase? a) Glutathione b) gamma-glutamylcysteine c) L-glutamate 20. How will the rate of Glutathione synthetase beta be immediately affected? a) It will slow down b) It will speed up c) It will not be effected Key:

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

1. Answer: B. One way to know if an organization is a reliable source is to see if it sites peer reviewed scientific journal articles. Another way would be to find out if the organization has a long history of reliably summarizing the available peer reviewed journal articles. Mechanism is something you should notice when evaluating a specific claim. It is not related to if a source is reliable. When evaluating a claim you should look for mechanism, evidence and source. This question is only asking you about what to notice about a source. 2. Answer: B. Scientists use each other’s work and this helps the scientific process to be self- corrective because if there is an issue with the original work, it gets discovered. 3. Answer: A. The more research on a topic the more the scientific community can reach a firm statement regarding a particular topic, this is scientific consensus. A scientific conclusion is a statement regarding the statistical results of a single experiment. 4. Answer: C and D. Both have measurement, dose and duration. A is missing dose and duration. B is missing measurement and duration. 5. Answer: E. The negative control should have the exact same conditions as the experimental procedure except for the one variable that your testing in this case the genetic treatment. Mode of delivery must be the same so there must still be an injection (just without the treatment) and must still draw blood. 6. Answer: B. The experimental group on day 15 has a higher standard error than the control group. Since the sample size is the same on day 15 the only thing that could be driving this is a greater standard deviation. This would be reflected by a greater variability in measurements. 7. Answer D: Reducing sample size in the control group means there is less likelihood of capturing all the variation in the population/the range of the SD…standard error is measurement of how well sample size captured the SD, so if sample size is reduced, standard error will be affected. 8. Answer: E. In an experiment you are comparing the control and the experimental treatments. So the first two answer choices are not correct. There are asterisks above days 15, 30 and 60 indicating a significant statistical difference between control and experiment on all the days that blood was taken during the course of treatment. Thus, we reject the null (which says there is no effect) and can conclude that the genetic treatment increases riboflavin concentration in the blood. 9. Answer: C. Tundra mice evolved in a cold climate which reduces permeability. Thus, they evolved more unsaturated phospholipids in the cells membranes of the cells that make up their feet to increase permeability (offset the cold) back into the range that can sustain life. Rainforest mice evolved in a warm climate which increases permeability. Thus, they evolved more saturated phospholipids in the cell membranes of the cells that make up their feet to reduce permeability back into the range that can sustain life. Thus, the species has a different evolutionary strategy to keeping permeability in the homeostatic range so their permeability to CO2 is equal. 10. Answer: A. Genetic variation arises by chance due to mistakes during cellular reproduction. The initial mutation that conferred resistance happened by chance…..but the entire population evolving resistance occurred because the antibiotic killed all the susceptible bacterial cells leaving only the resistance cells to reproduce.

11. Answer: D. Genetic variation arises by chance due to mistakes during cellular reproduction. The initial mutation that conferred resistance happened by chance…..but the entire population evolving resistance occurred because the antibiotic killed all the susceptible bacterial cells leaving only the resistance cells to reproduce. 12. Answer: C. N and O are in the same electronegativity category. So they will share electrons equally. 13. Answer: D. Two solutes are moving through the same cotransporter. Na+, is moving from a low concentration to a high concentration. So this must mean that riboflavin is moving from a high concentration to a low concentration. The riboflavin movement is providing the power for Na+ to move. 14. Answer: A. Ions are highly charged so they can never get through the cell membrane on their own because they get stuck interacting with the partial charges on the polar heads of the phospholipids. 15. Answer: C. This is secondary active transport, and you are already told that Na+ is moving from a low concentration to a high concentration. Riboflavin must be moving from a high concentration to a low concentration. The two solutes are moving in the same direction, from the small intestine (artificial cell) to the blood vessel (beaker water). So there must be a lower concentration of Na+ inside the artificial cell compared to the surrounding water. 16. Answer: A. The starting concentration inside the artificial cell will be lower than in the surrounding water. (See previous explanation) Water moves to areas of higher solute concentration, so water will move into the surrounding water. No water will move into the cell because no solute are moving into the cell. 17. Answer: B. The alpha helix and beta pleated sheet are at the secondary level of structure. Proteins are only function when they reach the tertiary level. (Although there are some proteins that need the quaternary level to be functional). 18. Answer: E. When an inhibitor binds changes the shape of an enzyme it does so by binding somewhere other than the active site. This prevents the substrate from binding to the active site. 19. Answer: C. If Glutathione synthetase alpha is not functioning the concentrations of its reactants (substrates) will increase. So L-glutamate and cysteine will increase because Glutathione synthetase alpha is not binding to them. Every product/substrate downstream will decrease in concentration because none of these substances can now be made. 20. Answer: A. Every product/substrate downstream of Glutathione synthetase alpha will decrease in concentration because none of these substances can now be made. Gamma- glutamylcysteine will decline in concentration and this is one of the reactants of Glutathione synthetase beta. When the concentration of the reactant decrease, the rate of the enzyme slows down.

BIOL113 Practice Set 1 lectures 1-7

Related Documents