Biology 12 DNA and Protein Synthesis Practice Name: 1. DNA is often called the "code of life". Actually it contains the code for a) the sequence of amino acids in a protein b) the sequence of base pairs c) producing mutations d) making a recipe 2. a) Name the molecule indicated by X. b) Where in a human cell does the process shown occur? c) What is the result of the process shown? d) After this process, cell division will occur. Why does the process need to occur before cell division? 3. Fill in the following chart that compares DNA and RNA: # of strands type of sugar location in cell bases types DNA ONLY ONE TYPE OF DNA RNA 4. Protein Synthesis using the DNA instructions to make a protein Location in cell where it occurs Types of RNA associated with this Transcription Translation Product
Metabolism Practice Section 1: What is an enzyme? 1. Which of the following statements is true about enzymes? a) 3D shape can vary and still be active b) they may catalyze only 1 specific reaction c) boiling temps do not affect activity d) they are unaffected by changes in ph 2. Enzymes a) give energy to metabolic reactions b) speed up metabolic reactions c) change the direction of reactions d) act as a buffer in metabolic reactions 3. Enzymes are specific. This means that they a) have a preferred ph b) have a preferred temperature c) have a particular substrate d) are only in certain cells 4. Most enzymes a) keep the speed of the chemical reaction constant b) inhibit the speed of the chemical reaction c) speed up the chemical reaction d) have no effect on the speed of the chemical reaction 5. Most enzymes are a) lipids b) carbohydrates c) proteins d) nucleic acids 6. One enzyme a) allows a chemical reaction in a cell to occur at moderate temperatures b) raises the energy of activation of a reaction c) speeds up 2 or more reactions in a cell d) cannot be used after the reaction 7. Each enzyme has a particular substrate because enzymes a) increase the energy of activation b) decrease the productivity of the cell c) always require coenzymes d) have active sites complementary in shape 8. Which of the following can be used to determine the rate of enzyme-catalyzed reactions? a) increase in activation energy b) increase in enzyme over time c) increase in product over time d) increase in coenzyme over time
Section 2: How Do Enzymes Work Lock and Key Theory 9. During enzymatic action, the enzyme a) becomes the product b) and substrate form a permanent complex c) is used up d) and substrate form a temporary complex 10. The maximum enzymatic rate occurs when of the active site is filled with substrate. a) 0% b) 25% c) 50% d) 100% 11. The place where the substrate fits onto the enzyme is called the a) active site b) inhibitor site c) receptor site d) E - S complex 12. Which of the following can be used to determine the rate of enzyme-catalyzed reactions? a) increase in activation energy b) increase in enzyme over time c) increase in product over time d) increase in coenzyme over time 13. a) If the following enzyme is a dehydration synthesis enzyme, which order would the diagrams have to be placed? b.) If the diagram represents a hydrolytic reaction, which order would the diagrams have to be placed? c.) In the diagrams above, what name would you give to the darker colored square?
14. If peptidase were added to side A, what would occur? (Peptidase is an enzyme that breaks peptides into amino acids) Section 3: Factors That Affect the Rate of Enzyme Catalyzed Reactions 15. Initially, as the substrate concentration is increased and there is a lot of enzyme, the reaction rate a) slows down b) speeds up c) stays the same d) speeds up then decreases 16. The graph shows the effect of ph on three different enzyme-catalyzed reactions. Which of the following would best describe the effect of ph on enzyme-catalyzed reactions? a) enzyme action increases as ph increases b) enzyme action decreases as ph increases c) enzymes work best in an acid environment d) each enzyme works best within a specific ph range 17. The diagram below represents the shapes of reacting molecules in a living system. When molecule X was added to the system, the amount of product decreased. Molecule X must be acting a) as a coenzyme. b) to denature the reactants. c) as a competitive inhibitor. d) to synthesize more of molecule W.
18. An experiment was performed to determine the effect of changing temperature on the speed enzyme activity. Substrate was placed in test tubes. The tubes were then placed in water baths of various temperatures. The substrate concentration in each tube was then measured. The results are graphed below. 10 C 40 C 50 C Give the amount of substrate in the tube at 10 C, 40 C and 50 C and explain why these substrate concentrations are different at each temperature. 19. The following data show the rate of an enzyme catalyzed reaction at various temperatures. a. Graph the data on the grid provided. b. Use the graphed data to describe the effect of temperature on the rate of enzyme activity. i. From 15 38 C ii. at 38 C iii. 38 43 C
c. Describe what would happen if the ph of the enzymes was changed from 7 to 2 d. Describe what would happen if a heavy metal was added to the enzyme 20. The graph shows the change in the rate of an enzyme-catalyzed reaction over time. a) Explain why the rate became constant at time X. b) Which labeled line correctly illustrates what would occur if more enzyme was added at time Y. Explain your answer. Section 4: Metabolism and Metabolic Pathways 21. If represents a metabolic pathway, then letter E would be a) a substrate b) a product c) an end product d) an enzyme 22. In a metabolic pathway a) product of 1 reaction becomes substrate of next reaction b) ATP is always released c) the same enzyme is used for all reactions d) the end product is never formed 23. Which of the following statements is false? a) metabolism is the sum of all chemical activities inside a cell b) a metabolic pathway involves only one chemical reaction c) one metabolic pathway may lead into another metabolic pathway d) the reactants in an enzymatic reaction are called substrates 24. An experiment investigating enzyme activity was carried out. A test tube was prepared containing substrate solution W and enzyme solutions 1 and 2. The reactions that occur in the test tube are summarized below: The letters represent substrates and products and the numbers represent enzymes. a. State two ways to increase the rate of production of product Y. b. A substance is added to the test tube containing substrate W. As a result, no product is formed. Suggest what this substance may be and explain how it achieves these results.
25. An experiment investigating enzyme activity is carried out. A test tube is prepared containing substrate solution W and enzyme solutions 1, 2 and 3. The reactions that occur in the test tube are summarized to the right. a) Describe two ways in which the rate of production of product Y can be increased. b) A substance is added to the test tube. As a result, no product Y is formed, but product Z is still formed. Explain why. Section 5: Cellular Respiration and ATP 26. ATP is the energy currency of cells because it a) is a large molecule b) carries a positive charge c) contains high energy phosphate bonds d) is made from glucose 27. What is the common energy currency in cells for the synthesis of molecules? a) glucose b) proteins c) lipids d) ATP 28. ATP contains a) 1 phosphate b) 2 phosphates c) 3 phosphates d) no phosphates 29. The high energy bond in ATP is found in or between a) adenine base b) cytosine base c) adenosine d) the phosphate groups 30. When ATP is broken down a) ADP is formed b) ADP + phosphate is formed c) ADP + phosphate + energy is formed d) Lactic acid is formed 31. Which of the following would be considered normal energy sources for ATP production? a) Carbohydrates, fats and proteins b) Carbohydrates and fats c) Carbohydrates only d) Carbohydrates and proteins 32. Which of the following statements is the most likely to be incorrect? A breakdown of protein to produce ATP may occur under the following conditions. a) The individual is exercising at an extreme level b) The individual has a low body fat percentage c) The individual is not very fit and works out too hard d) An individual does not do any exercise
33. During exercise, most ATP is made a) During aerobic cellular respiration b) During anaerobic cellular respiration c) When muscle cells contain low numbers of mitochondria d) When muscle cells contains low concentrations of mitochondrial enzymes 34. Which substrate can provide the highest theoretical ATP production? a) Carbohydrates b) Triglycerides (fats) c) Nucleic acids d) Proteins 35. The diagram below represents a molecule found in all living cells. a) What is this molecule called? b) What occurs if one phosphate is removed? Why? c) Name one cellular function that requires the above molecule. Section 6: Higher Level Thinking Question (application of knowledge) 36. The cells of the thyroid gland are able to take in iodine atoms and may contain iodine concentrations up to 25 times that of the surrounding tissue fluid. In an experiment designed to study factors affecting the rate of iodine intake, thyroid cells were cultured and placed in a medium containing normal blood concentrations of iodine. Temperature and glucose concentrations were varied and the effects recorded. The results of the study are shown in the table below. a) Explain the observed results for sample A. b) Explain the observed results for sample B. c) Explain how the movement of amino acids into the cells would be affected by the conditions in sample B