2. Lactase is an enzyme secreted into the digestive tract. Answer the following ...

2. Lactase is an enzyme secreted into the digestive tract. Answer the following questions related to lactase (hint: enzymes are specialized proteins): a. Begin with the general role of DNA and RNA in the nucleus in making lactase (1 mark). b. Name three organelles that would be involved in the production and processing of this enzyme and list the function of each organelle (3 marks). c. If there was an extreme change in pH, what might happen to the lactase enzyme (1 mark)? 3. ATP is essential for life, as our cells need it to do cell work. a. Which part of the ATP molecule is used to do cell work (1 mark)? b. List 3 different types of cell work and provide a specific example for each (3 marks). c. We recycle over 40kg of ATP per day! Use a diagram or equation to show how the ATP cycle makes this possible (1 mark). 4. Cellular respiration generates ATP for our cells. a. Write the complete equation for cellular respiration, including the total number of ATP produced (1 mark). b. Which step(s) in cellular respiration is/are anaerobic, how many ATP are produced, and is oxygen required (1.5 marks)? c. Which step(s) in cellular respiration is/are aerobic, how many ATP are produced, and is oxygen required (1.5 marks)? d. Why do hockey players have such short shifts (45 seconds) on the ice (hint: which pathway are they primarily using to generate ATP) (1 mark). 5. ‘Form fits function’ is a key concept in biology. Use this concept to answer the following questions: ​a.​What is the general purpose of cell junctions in our body (1 mark)? ​b.​What junctions do we find in high proportions in the bladder (1 mark)? Describe the ​structure and function of these junctions and explain how their structure fits their ​function in the bladder (3 marks). ​ 6. As you have learned, our organ systems are interconnected. List the 3 organ systems that are involved in acquiring energy and explain the most important function of each organ system in doing so (3 marks). Pick one of these organ systems, and explain the effect that it would have on the other 2 if it stopped functioning (2 marks). 7. You are standing outside on a cold day and start to shiver. What major physiological process is taking place to make sure you don’t get too cold (1 mark)? What type feedback loop is involved (1 mark)? Using the terms receptor, control centre and effector, and providing specific examples of each, describe how your body protects itself from getting too cold (3 marks). 8. Mutations can be spontaneous or caused by environmental factors. a. Explain the difference between a substitution mutation and a frameshift mutation (2 marks). b. Are mutations always harmful? Explain using the following DNA sequence as your template: TAC ACC TTG (3 marks). Show your work. You will be given the Genetic Code on the test. 9. You are training for the 10 k run at the Ottawa Race weekend in May and are concerned about your nutrition. Use this scenario to explain the following: a. When you ‘carb’ load the night before, which polysaccharide will your skeletal muscles and liver store to help fuel your run? What are the specific monomers of this polysaccharide, and what reaction links them together? Is the formation of this polysaccharide an example of anabolic or catabolic metabolism? (3 marks) b. What snack would be a more beneficial source of energy before your training sessions: a banana rich in glucose or a high fibre salad? Explain (2 marks). 10. After transcription, mRNA is processed before it can exit the nucleus. a. Using a diagram, explain the steps involved in mRNA processing (4 marks). b. What would happen if an mRNA transcript left the nucleus without first being processed (1 mark)?