Practice set 1 lecs 1-7

pdf

School

Binghamton University *

*We aren’t endorsed by this school

Course

501

Subject

Biology

Date

Jan 9, 2024

Type

pdf

Pages

Uploaded by ChefTitanium12870

Practice set 1: Covers lectures 1-7 Complete each set of questions as we advance through the course material. Every question in this exam is connected! In healthy individuals. ingested glucose is absorbed into the blood stream through membrane channels. Later, the glucose is transported via facilitated diffusion through Glucose Transporter proteins (GLUT) from the blood stream and into various cells of the body. These cells use the glucose as an energy source or store it for later use. Any glucose that remains in the blood eventually ends up in the filtrate which is fluid passing through the kidney that eventually becomes urine. Certain kidney cells contain Sodium Glucose Cotransporter membrane proteins (SGLTs). which transport glucose against its concentration gradient from the filtrate inside kidney cells and back into the blood. Sodium (Na”) also moves through the SGLT. This transport slightly and temporarily increases blood glucose levels. Patients with type II diabetes have malformed GLUT proteins so glucose cannot be transported from the blood and into the cells of the body. Thus. these patients experience constant elevated blood glucose levels. Further. the proper working of SGLT exacerbates elevated blood glucose levels. Questions 1-2 cover lectures 1-2: 1. Julia has just been diagnosed with type II diabetes so she reads the Wikipedia page for type IT diabetes. It states that, among other dietary changes. increasing one’s fiber intake to at least 25 grams per day improves health outcomes for those with type II diabetes. This statement is followed by a link to a peer reviewed scientific paper which describes how fiber affects blood glucose levels. The paper states that since fiber is an indigestible carbohydrate (not broken down into individual glucose units) it does not interact with Glucose Transporter (GLUT) proteins and s0 is not transported into the blood. Therefore, it does not increase blood glucose levels. The information in the peer reviewed paper is an example of a) Evidence b) Source ¢) Mechanism d) None, because it is not scientific enough 2. The authors of the paper. Sinclair et al. describe their experiment testing the effects of fiber on blood glucose levels as double blind. This means that the experimental and control participants were coded such that researchers collecting data were not aware of which individuals were in the experimental group and which individuals were in the control group. Further. the participants themselves did not know which group they were in. This methodology directly demonstrates which strength of science a) Scientists use each other’s work b) Only falsifiable hypotheses are used c) Scientists remain objective d) Conclusions change based on new evidence

Questions 3-10 cover lectures 1-5: 3. Sinclair et al cite many research studies in their paper. one of which measured the lifetime instances of contracting type II diabetes after being fed a high fiber diet from weaning to death. This study was conducted on mice. Compare the cells in the feet of the deer mouse who is native to a cool climate with the African pygmy mouse who is native to a hot climate: The deer mouse feet will have more phospholipids than the African pygmy mouse feet. The deer mouse feet will have permeability to CO2 compared to the permeability of H2O0 in the African pygmy mouse feet. a) Saturated. Equal. b) Saturated. Greater. ¢) Unsaturated. Less. d) Unsaturated. Greater. e) Unsaturated. Equal. 4. Next, Julia reads the Center for Disease Control (CDC) website on type II diabetes. The CDC bases its recommendations on the entire body of literature that has been published regarding type 1I diabetes. Therefore, it represents a) Scientific theory b) Scientific consensus ¢) Hypothesis d) Prediction 5. Julia has a conversation with her doctor about treatment options for her type II diabetes. Among other suggestions. her doctor recommends an SGLT inhibitor drug. Julia returns home and searches the internet to find out more about the SGLT inhibitor. She reads a peer reviewed scientific paper which tests the affect of the SGLT inhibitor on blood glucose levels. Which of the following is a proper hypothesis? a) SGLT inhibitors will reduce blood glucose levels in patients with type II diabetes. b) 10 mg of SGLT inhibitor taken daily will reduce blood glucose levels in patients with type II diabetes during a 30-day course of treatment. ¢) 10 mg of SGLT inhibitor taken daily along with 5 mg of insulin will reduce blood glucose levels compared to taking just insulin alone during a 30-day course of treatment. d) A.B.C e) BandC 6. The authors of the SGLT inhibitor paper seek to uncover if human patients already taking the drug Metformin would have an even greater reduction in blood glucose levels if they also took an SGLT inhibitor. The methods describe that there are 50 type II diabetes patients in the experimental group and 50 in the control group. The experimental patients take Metformin alone

for 30 days and then take Metformin with an SGLT inhibitor (inside a capsule) for another 30 days. Blood glucose levels are tested twice per day. What is the most scientifically robust procedure for the negative control group? a) Take neither drug. b) Take nothing for 30 days and then metformin with an empty capsule for 30 days. ¢) Take metformin for 60 days. d) Take metformin for 30 days and then metformin with an empty capsule for 30 days. 7. Results of the experiment can be seen below. Mean blood glucose levels over 60 days *% Mg/di e Contrcl ) = Experimental Day1 Day 45 Day 60 At which time point can the authors be most confident in their rejection of the null hypothesis? a) Day 1 b) Day 45 c) Day 60 d) Day 45 and day 60 equally 8. In which group did the authors achieve a sample mean that is closer to the population mean? a) Control b) Experimental c) Day45 d) Day 60 9. In which group is there most likely to be a wider range of responses to treatment? a) Control b) Experimental c) Day45 d) Day 60 10. Generally speaking. when standard deviation is narrow it means a) The experimental design was poor b) Sample size should be increased ¢) The population does not show a variable response

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

d) The population is more favorable to research Questions 11-16 cover lectures 5-6: 11. )J\ Jj\ Scale of electronegativi ~ 1.5-1.9 2.0-2.9 3.0-4.0 T H NH, Metformin’s chemical structure is shown below NH NH Be. AL Si H.B.C N.O.F Generally, how does N and H interact when forming a chemical bond? 12. 13. 14. 15. a) Ions. with a lost or gained electron. b) Metallic bond. with distanced valence electrons. ¢) Unequal sharing of electrons in the valence shells. d) Equal sharing of electrons in the valence shells. Theoretically speaking. what material would the drug be coated in so that it can get through the cell membrane on its own. a) Carbohydrate b) Nucleic acid ¢) Lipid Remember that Glucose Transporter protein (GLUT) is located embedded in the cell membrane of various cells of the body and moves glucose from the blood stream and into the cells via facilitated diffusion. Therefore, GLUT will be (most) active at which state? a) When there is a high concentration of glucose in the blood b) When there is a low concentration of glucose in the blood ¢) When there is a high concentration of glucose in the kidney d) When there is a low concentration of glucose in the kidney Remember that Sodium Glucose Cotransporter membrane proteins (SGLTSs) transport glucose against its concentration gradient from the filtrate in the kidneys and back into the blood. Sodium (Na") also moves through simultaneously. What kind of membrane transport is this? a) Passive diffusion b) Facilitated diffusion ¢) Primary active transport d) Secondary active transport In another paper that Julie reads the researchers are interested in understanding the mechanism of action of the SGLT inhibitor. They set up an experiment in which an artificial cell represents a kidney cell. It has a SGLT and aquaporins embedded in the cell membrane. The artificial cell is submerged in a beaker of water. At the start of the experiment. they put 9 M of glucose in the beaker fluid and 2 M glucose inside the artificial cell. Where should sodium be placed to prompt glucose to start moving? And once it does, in which direction will glucose move? a) A high concentration of sodium must be created inside the artificial cell. Glucose will move into the artificial cell.

b) A high concentration of sodium must be created in the beaker fluid. Glucose will move out of the artificial cell. ¢) A high concentration of sodium must be created inside the artificial cell. Glucose will move out of the artificial cell. d) A high concentration of sodium must be created in the beaker fluid. Glucose will move into the artificial cell. 16. Some time after glucose has moved. where will water move? a) Water will move out of the artificial cell b) Water will move into the artificial cell ¢) Water will not move Questions 17-20 cover lectures 4 & 7: 17. Remember that in people with type II diabetes. GLUT doesn’t work so blood glucose levels remain perpetually high. This problem is exacerbated by the proper working of SGLT which transports both glucose and sodium from the filtrate in the kidney and into the blood stream. The SGLT inhibitor Julia’s doctor recommended eliminates this exacerbation by binding to a site other than where glucose and sodium bind. What kind of inhibition is this? a) Allosteric: reversible b) Allosteric; nonreversible c) Competitive: reversible d) Competitive: nonreversible e) Cleaving amino acids: nonreversible 18. Amylose is a kind of carbohydrate found in many root vegetables. When it is eaten it is first broken down by the enzyme alpha-amylase into maltose, maltotriose and dextrin. All three of these substances get further broken down in the pancreas by the enzyme sucrase. A diagram of this metabolic pathway can be seen below. alplase SU Amylose — Maltose ~ — Glucose Maltotriose — Glucose Dextrin —+ Glucose Another kind of diabetic medication inhibits sucrase. What immediate affect does sucrase inhibition have on glucose levels? What immediate affect does sucrase inhibition have on alpha- amylase activity? a) Glucose levels increase. Alpha-amylase activity speeds up. b) Glucose levels increase. Alpha-amylase activity slows down. ¢) Glucose levels decrease. Alpha-amylase activity speeds up. d) Glucose levels decrease. Alpha-amylase activity slows down. 19. Type II diabetes can also increase the risk of urinary tract bacterial infections. Julia develops a urinary tract infection caused by the bacteria E. coli (generation 0). An antibiotic is prescribed. After five days. all the bacterial cells in Julia’s urethra have been killed except for one (generation 5). After ten days. there are many E. coli cells in Julia’s urethra. and they are all

20. resistant to the antibiotic (generation 10). Resistance is conferred by a mutation in a specific gene. In the generation of E. coli that lived before antibiotics were taken (generation 0) a) One or some cells had a resistance mutation. This mutation arose by chance. b) All the cells had a resistance mutation. This mutation arose by chance. c) One or some cells had a resistance mutation. This mutation arose because of exposure to the antibiotic. d) All the cells had a resistance mutation. This mutation arose because of exposure to the antibiotic. After ten days the entire E. coli population (generation 10) had evolved the resistance mutation. This most likely occurred because a) All the cells in the population independently acquired the resistance mutation by chance. b) The cells in the population inherited the mutation from surviving cells in previous generations. Answer: C. This mechanism is scientific. It mentions the GLUT proteins and how its lack of interaction with GLUT means that it is not brought into the blood as glucose. Answer: C. Sinclair et al are forcing themselves to be objective by setting up a double-blind study. Data collection will proceed in an unbiased way because the researchers collecting the data don’t know which participants are in which group. This is very different from what Andrew Wakefield did in the retracted paper we discussed in lecture. Answer: D. Deer mice live in a cool climate so they will compensate for that reduced permeability (due to temperature) by evolving more unsaturated phospholipids in the cell membrane of their feet. However. CO2 is always more permeable than H20 because it is small and nonpolar. So the deer mice will have greater permeability to CO2 compared to H20 in the African pygmy mouse feet. Answer: B. Scientific consensus is based on the full body of literature. It is an overall conclusion about a specific topic. It is true or the closet to true that we have gotten so far. A scientific theory is a framework that explains a broad phenomenon that we see in nature. Answer: A. This option is a broad statement. Options B and C are specific. measurable and include duration and dosage. These are predictions. Answer: D. The experiment seeks to uncover if the addition of SGLT2 to metformin will reduce blood glucose levels. Therefore. the negative control group should take the metformin for 30 days and then take metformin with an empty capsule (so no SGLT inhibitor) for another 30 days. This ‘way. they can compare the two groups and find out if the addition of SGLT inhibitor to metformin improves blood glucose levels. Answer: B. Day 45 has two asterisks and day 60 has one asterisk. More asterisks indicate less of a chance of being wrong in the rejection of the null hypothesis. Thus. we can be more confident in our rejection of the null hypothesis at day 45. Answer: B. Standard error bars are smaller. This indicates the sample mean is closer to the population mean.

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

10. 11. 12. 13. 14. 15. 16. 17. 18. 19. Answer: A. Because standard error bars are high. This means that the sample size was insufficient to capture the variation in the population. probably because standard deviation is wider. Answer: C. When standard deviation is narrow it means that the population does not show a variable response to the treatment. This means that you don’t need a large sample size to capture all the variation because there is none. Answer: C. N and H are in different electronegativity categories so the bond will be a polar covalent bond. This means electrons are shared unequally (with unequal force). Answer: C. Lipids are nonpolar. Nonpolar things can get into the cell membrane while polar things can not get in without getting stuck to the polar heads of the phospholipids. Polar things need assistance to get into the cell membrane. Answer: A. Facilitated diffusion moves solutes from high to low. So GLUT will be most operational when there is a high concentration in the blood and it is moving the glucose into the cells of the body. Answer: D. Both glucose and sodium are moving through the SGLT. but glucose is moving against its gradient. Therefore, this must be powered by sodium moving with its gradient. This is secondary active transport. Answer: C. SGLT moves glucose against its concentration gradient by harnessing the energy released by sodium moving with its gradient. SGLT needs to move glucose from inside the cell (representing the filtrate in the kidney cell) and into the beaker water (representing the blood). So The concentration of sodium needs to be high inside the cell to get glucose moving from inside to outside. Answer: A. After some time all of the glucose and sodium will have been moved out of the cell so water will move out of the cell. Answer: A. When the inhibitory molecule binds somewhere other than the active site it is called allosteric inhibition. This is reversible if the concentration of glucose gets very high. Answer: D. When sucrase is inhibited. it stops making glucose. So glucose levels decrease. Sucrase is no longer binding with maltose, maltotiose and dextrin so their levels increase. This causes alpha-amylase activity to slow down because there is more of its product (maltose, maltotiose and dextrin) compared to its reactant (amylose). Answer: A. All mutations arise by chance due to mistakes in DNA replication. Only one or some cells had the mutation at generation 0 because all but one are killed by the antibiotic after five days. If they all started out with the mutation then none would have died after 5 days of treatment.

20. Answer: B. This is how evolution works. Genetic mutations that survive changes in environment (in this case, antibiotic use) will pass those mutations on to their offspring. So subsequent generations will all have that mutation. Thus. the population has now evolved (changed).

Practice set 1 lecs 1-7

Related Documents