SCI-228 Week 4 Midterm

SCI-228 Week 4 Midterm Grading Summary Grade Details - All Questions Page: 1 2 Question 1. Question : (TCO 1) Control subjects in a double-blind test of a new drug are Student Answer: informed of what drug they are getting. informed of what drug they are getting but their private physicians are not. given larger doses of the drug. infected with a different disease than the experimental subjects. not given the experimental drug but are otherwise treated the same as the experimental subjects. Instructor Explanation: Chapter 1 Points Received: 4 of 4 Comments: Question 2. Question : (TCO 1) A scientific theory Student Answer: becomes static. cannot be challenged. is subject to modification. cannot be changed. is irrefutable. Instructor Explanation: See Chapter 1. Scientific theories continue to be tested and sometimes may be modified or discarded. Points Received: 4 of 4 Comments: Question 3. Question : (TCO 1) Each of the following is a testable hypothesis, except Student Answer: avoiding contact with other people reduces the chance of catching a cold. taking zinc lozenges at the first sign of cold symptoms reduces throat irritation. being a good driver makes you less likely to catch a cold. sleeping 8 hours a night reduces the severity of a cold. All of the above Instructor Explanation: Chapter 1 Points Received: 4 of 4 Comments: Question 4. Question : (TCO 2) Which particles are found in the nucleus of an atom? Student Answer: Only neutrons Protons and electrons Protons and neutrons Only electrons Only protons Instructor Explanation: Chapter 3 Points Received: 4 of 4 Comments: Question 5. Question : (TCO2) Which of the following is not an example of a pure substance? Student Answer: K2CO3 Water Orange juice Aluminum foil Mercury in a thermometer Instructor Explanation: Chapter 3 Points Received: 4 of 4 Comments: Question 6. Question : (TCO 2) Which of the following is a physical property of both liquids and solids? Student Answer: Has its own shape Has slow moving particles Has strong interactions between its particles Has randomly arranged particles Has large spaces between the molecules Instructor Explanation: Chapter 2 Points Received: 4 of 4 Comments: Question 7. Question : (TCO 2) Which of the following is a not a homogeneous mixture? Student Answer: 5% glucose IV solution Iced tea Salt water Skim milk Ice cream float Instructor Explanation: Chapter 3 Points Received: 4 of 4 Comments: Question 8. Question : (TCO 3) Atom X forms a -2 anion. Atom Y forms a +1 cation. Which is the overall charge of the polyatomic ion XY4? Student Answer: 0 -1 +4 +2 +1 Instructor Explanation: See Chapter 4. One X ion has an overall charge of -2. Four Y ions have a charge of +4. -2 + 4 = +2. Points Received: 4 of 4 Comments: Question 9. Question : (TCO 3) Emily has a box that contains 0.01 mole of aluminum. How many particles of aluminum are in the box? Student Answer: 6.02 3.01 × 1021 3.01 × 1022 6.02 × 1022 6.02 × 1021 Instructor Explanation: Chapter 5 Points Received: 4 of 4 Comments: Question 10. Question : (TCO 3) Which of the statements about transition metals is true? Student Answer: Transition metals can gain or lose electrons to form anions or cations. Transition metals can gain a variable number of electrons to form two or more different anions. All transition metals form at least two different ions. All of the above None of the above Instructor Explanation: Chapter 4 Points Received: 4 of 4 Comments: Question 11. Question : (TCO 4) An unknown solution has a pH of 2. This solution is Student Answer: extremely acidic. moderately acidic. neutral. slightly basic. extremely basic. Instructor Explanation: Chapter 7 Points Received: 4 of 4 Comments: Question 12. Question : (TCO 4) In water, a substance that doesn’t ionize in solution is called a Student Answer: nonelectrolyte. strong electrolyte. base. acid. weak electrolyte. Instructor Explanation: Chapter 6 Points Received: 4 of 4 Comments: Question 13. Question : (TCO 4) How much 0.70 M HNO3 could you make from 200 mL of 1.40 M HNO3? Student Answer: 100 mL 196 mL 400 mL 83 mL 0.075 mL Instructor Explanation: See Chapter 6. V1C1 = V2C2. 200 mL × 1.40 M = V2 × 0.70 M. V2 = (200 mL × 1.40 M) ÷ 0.70 M = 400 mL. Points Received: 4 of 4 Comments: Question 14. Question : (TCO 5) When a -COOH group is substituted for a hydrogen atom in hydrocarbon, the hydrocarbon becomes Student Answer: a carboxylic acid. a protein. hydrophobic. an alcohol. an amine. Instructor Explanation: Chapter 8 Points Received: 4 of 4 Comments: Question 15. Question : (TCO 5) The presence of more than one polypeptide chain is described as _____ protein structure. Student Answer: primary secondary tertiary quaternary infinite Instructor Explanation: Chapter 8 Points Received: 4 of 4 Comments: Question 16. Question : (TCO 6) Where does photosynthesis occur in a eukaryotic cell? Student Answer: Smooth endoplasmic reticulum Mitochondrion Ribosome Chloroplast Nucleolus Instructor Explanation: Chapter 9 Points Received: 4 of 4 Comments: Question 17. Question : (TCO 6) Active transport _____. Student Answer: does not require an energy source moves solutes down their concentration gradients does not require the cell to expend energy All of the above None of the above Instructor Explanation: Chapter 9 Points Received: 4 of 4 Comments: Question 18. Question : (TCO 6) Which of the following statements is true? Student Answer: Most enzymes are lipids. An enzyme's function is never affected by antibiotics. Enzymes are the reactants in a chemical reaction. Enzymes catalyze specific reactions. An enzyme's function requires inhibitors. Instructor Explanation: Chapter 9 Points Received: 4 of 4 Comments: Question 19. Question : (TCO 7) The first stage of aerobic respiration is _____. Student Answer: the Calvin cycle the electron transport chain the citric acid cycle lactic acid fermentation glycolysis Instructor Explanation: Chapter 11 Points Received: 4 of 4 Comments: Question 20. Question : (TCO 7) Anaerobic respiration occurs _____. Student Answer: without bacteria without ATP without CO2 with O2 without O2 Instructor Explanation: Chapter 11 Points Received: 4 of 4 Comments: Question 21. Question : (TCO 7) Which of the following is (are) produced during cellular respiration? Student Answer: Water Carbon dioxide Glucose Water and carbon dioxide Water and glucose Instructor Explanation: Chapter 11 Points Received: 4 of 4 Comments: Question 22. Question : (TCO 7) Which of the following statements is incorrect? Student Answer: Oxygen is a product of photosynthesis; carbon dioxide is a product of cellular respiration. Oxidation is the gain of electrons; reduction is the loss of electrons. Lactic acid is a product of anaerobic respiration; ethyl alcohol is a product of fermentation. Oxidation is the loss of electrons; reduction is the gain of electrons. Glucose is a product of aerobic respiration; lactic acid is a product of anaerobic respiration. Instructor Explanation: Chapter 11 Points Received: 4 of 4 Comments: Question 23. Question : (TCO 7) Which of the choices below best describes metabolism? Student Answer: Metabolism is converting simpler compounds to more complex compounds. Metabolism is the rate at which cells use energy. Metabolism is the rate at which cells release heat. Metabolism is converting complex compounds to simpler compounds. Metabolism is all chemical processes that occur within cells. Instructor Explanation: Chapter 11 Points Received: 4 of 4 Comments: Question 24. Question : (TCO 7) Cellular respiration releases energy from glucose. Which form does this energy take? Student Answer: ATP and heat Oxygen only Heat only ATP and NADH ATP only Instructor Explanation: Chapter 11 Points Received: 4 of 4 Comments: Question 25. Question : (TCO 7) How is respiration (the act of breathing) different from cellular respiration? Student Answer: Respiration produces ATP; cellular respiration is gas exchange. Respiration is gas exchange; cellular respiration produces ATP. Respiration produces glucose; cellular respiration produces oxygen. Respiration uses glucose; cellular respiration produces glucose. Respiration produces glucose; cellular respiration is gas exchange. Instructor Explanation: Chapter 11 Points Received: 4 of 4 Comments: Page: 1 2 * Times are displayed in (GMT-07:00) Mountain Time (US & Canada) Grading Summary These are the automatically computed results of your exam. Grades for essay questions, and comments from your instructor, are in the "Details" section below. Date Taken: 7/31/2016 Time Spent: 2 h , 03 min , 26 secs Points Received: 120 / 120 (100%) Question Type: # Of Questions: # Correct: Multiple Choice 25 25 Short 2 N/A Essay 1 N/A Grade Details - All Questions Page: 1 2 Question 1. Question : (TCO 6) What are the differences and similarities between prokaryotic and eukaryotic cells? You must list both differences and similarities for full credit. Student Answer: Differences between prokaryotic and eukaryotic cells: For Prokaryotic cells: -no nucleus -no membrane-bound organelles -abundant -unicellular -cells have sticky capsule -have cell wall -live in most environments -usually smaller than eukaryotes -divide through binary fission, which is simple cell division For Eukaryotic cells: -have a nucleus that contain DNA -cells have organelles -can be either unicellular or multicellular -has a cytoskeleton -some eukaryotes have a cilia -usually bigger than prokaryotes -undergo mitosis Similarities: -both have ribosomes -both have unique DNA -both have a cytoplasm -both havea cell membrane -both prokaryotic cells and eukarotic cells have some cells that have flagella Instructor Explanation: See Chapter 9. Prokaryotes are structurally simpler than eukaryotic cells. They lack a nucleus and membrane-bound organelles. Prokaryotes have a cell wall (such as plant cells, unlike animal cells). Prokaryotes are 10–100 times smaller than eukaryotic cells. Features in common include a cell membrane, DNA, and ribosomes. Points Received: 5 of 5 Comments: Question 2. Question : (TCO 3). What is the molar mass of calcium sulfate, CaSO4? You must show your work for full credit. Student Answer: 1 Ca is 40.078 = calcium 1 S is 32.065 = sulfur 1 O is 16.00, but since there are 4 of them we multiply by 4 so it's 64.00 = oxygen 40.078 + 32.065 + 64.00 = 136.143 g/mol Answer: 136.14 g/mol Instructor Explanation: See Chapter 5. The atomic masses are Ca = 40.08, S = 32.06, and O = 16.00. The molar mass is 40.08 + 32.06 = (4 × 16.00) = 136.14 g. Points Received: 5 of 5 Comments: Question 3. Question : (TCO 7) Compare fermentation and aerobic cellular respiration. Include details regarding the reactions that take place and the location in the cell where these reactions occur. Student Answer: Fermentation is a metabolic process where carbohydrates like sugar are converted into alcohol or acid. There are two types of fermentation, which is ethanol fermentation and lactic acid fermentation. Ethanol fermentation is used to produced beer, wine, and bread. Lactic acid fermentation is used to convert lactose into lactic acid when producing yogurt. Fermentation is a method for harvesting chemical energy without the use of oxygen or any other electron transport chains. When oxygen is absent, cells would use fermentation to produce ATP by substrate-level phosphorlytation. Pyruvate would serve as an electron acceptor for oxidizing NADH back to NAD+, which would be reused in glycolysis. Fermentation takes place in the cell's cytoplasm. In prokaryotic cells, the metabolic processes all take place in the cytoplasm, but in eukaryotic cells, fermentation takes place in the cytoplasm, then the other forms of respiration take place in the mitochondria. Aerobic cellular respiration, however, is the process which our cells get energy to function through the use of oxygen. Oxygen allows for a larger amount of energy to be produced. Aerobic cellular respiration occurs mainly in eukaryotic cells, and takes place mostly inside the mitochondria. Aerobic cellular respiration goes through the stages of glycolysis, prepatory reaction, citric acid cycle, and electron transport train. The main thing both processes have in common are that both go through glycolysis, but without oxygen, fermentation cannot proceed to the electron transport chain. Instructor Explanation: Cellular respiration requires oxygen to harvest 36–38 molecules of ATP from the breakdown of each molecule of glucose. The reaction of cellular respiration includes glycolysis, which occurs in the cytoplasm of the cell; the reactions of the citric acid cycle, which occur in the lumen of the mitochondria; and the electron transport chain, which is built into the inner membranes of the mitochondria. The redox reactions of the electron transport chain power a proton pump that is responsible for the bulk of the ATP generated. Fermentation, on the other hand, is a process that occurs in the absence of oxygen. Like respiration, it begins with the reactions of glycolysis, but the end product of glycolysis, two molecules of pyruvic acid, are then reduced to either lactic acid or ethanol, depending upon the organism. This bypasses the major ATP-generating steps of respiration and yields only the two ATP produced by glycolysis from the breakdown of glucose. Points Received: 10 of 10 Comments: Page: 1 2