Unit 2: The Properties of Water, Organic Macromolecules, Enzymes, Digestion (questions)

Transcription

1 Table 1: ph Values of Common Substances 1. Observe Table 1, which substance has the highest concentration of H+ ions? a. Water b. Baking soda solution c. Lemon juice d. Sodium hydroxide solution 2. Which substance in Table 1 is neutral? a. Vinegar b. Lemon juice c. Baking soda solution Figure 2.3: Enzyme action d. Water Use Figure 2.3 to answer the following questions 3. What is the function of an enzyme? a. To break apart the reactants in a reaction b. To raise the activation energy of a reaction c. To break apart the products in a reaction d. To lower the activation energy of a reaction 4. How could you best describe the reaction in Fig. 2.3? a. It is a synthesis or building reaction that releases energy b. It is a neutralization reaction that releases energy c. It is a decomposition or breaking apart reaction that releases energy d. It is a synthesis or building reaction that stores energy 5. Water molecules are held together by a specific type of bond called a a. Hydrogen bond b. Oxygen bond c. Ionic bond d. James Bond

2 6. The monomer of a protein is called a(n) a. Monosaccharide b. Nucleotide c. Peptide d. Amino acid Fig What macromolecule is represented in Fig. 2.5? a. Lipid b. Nucleic acid c. Protein d. Carbohydrate 8. A map of eastern North America, showing the ph of rainfall in the various states, indicates that the ph of rain in New York State varies from 4.22 to According to these figures, the most acidic rainfall in New York State has a ph of. a b c d Amino acid is to protein as a. Fat is to lipid b. DNA is to RNA c. Sugar is to fat d. Simple sugar is to starch 10. Identify the reactant(s) in the chemical reaction, CO 2 + H 2 O H 2 CO 3. a. CO 2, H 2 O, and H 2 CO 3 b. CO 2 and H 2 O c. H 2 CO 3 d. CO 2

3 11. In a water molecule, shared electrons spend more time around the oxygen atom than the hydrogen atoms. As a result, the oxygen atom is? a. slightly negative b. very negative. c. slightly positive. d. very positive. 12. Enzymes affect the reactions in living cells primarily by changing the a. Products of the reaction b. Speed of the reaction c. Temperature of the reaction to a lower temperature d. ph of the reaction 13. Solutions that contain concentrations of OH- ions in excess a. Have ph values below 7 b. Are acids c. Are bases d. Are enzymes 14. Which of the following statements about enzymes is NOT true? a. Enzymes work best at a specified ph b. All enzymes have the same shape as their substrates c. Enzymes are proteins d. The the three dimensional shape of an enzyme (active site) allows it to catalyze reactions Figure Using Tables and Graphs According to Figure 2 5, at what temperature do the two enzymes have the same amount of activity? 16. Using Tables and Graphs According to Figure 2 5, which enzyme has an optimum temperature of 40 C?

4 17. Which statement is true? a. Simple sugars are made of polysaccharides like starch b. Glycerol is made of fatty acids c. RNA molecules are made of nucleotides d. Amino acids are made of proteins 18. Plants use special forces to move water through their bodies. These forces are a. Adhesion, cohesion and van der waals forces b. Adhesion and cohesion only c. Adhesion, cohesion and capillary action d. Adhesion and capillary action only 19. Plants use stomata to regulate gas exchange. Which of the following statements is correct with regards to how gases move into and out of the stomata? a. Oxygen moves in and Carbon dioxide moves out b. Oxygen moves out and Carbon dioxide moves in c. Carbon dioxide moves in and Oxygen moves in d. Carbon dioxide moves out and Oxygen moves out 20. What macromolecule is represented in Fig. 27.2? Fig 27.2 a. Nucleic acid b. Protein c. Carbohydrate d. Lipid 21. What is the monomer of this macromolecule? a. Glucose b. Nucleotide c. Polypeptide d. Disaccharide

5 22. This diagram represents the lock and key model of an enzyme with its substrate. Which molecule is used up during this chemical reaction? a. Maltose b. Enzyme c. Glucose d. Active site 23. Is this reaction a synthesis or decomposition reaction? a. Synthesis b. Decomposition 24. It is known that enzymes are ph, temperature and substrate specific. If an enzyme works best at a basic ph and low temperature and is put into an acidic ph and high temperature. How would the enzyme s active site be affected? a. Nothing would happen and the active site would remain unchanged b. The active site would change shape and stop working (become denatured) c. The substrate would change and the active site would continue to work d. None of the above 25. The accessory organs in the digestive system include all of following except a. Tongue b. Liver c. Pancreas d. Stomach See answers below!

6 ANSWERS: 1. C (Lower ph = more acidic therefore more H+ ions) 2. D (Ph 7 = neutral) 3. D (enzyme = catalyst = lowers energy to run reaction) 4. C (start with polymer = proteins and breaks down into monomers - amino acids) 5. A (see diagrams in book) 6. D 7. A 8. B (the lower the values, the more acidic the substance) 9. D (monomer to polymer) 10. B (what you START the reaction with) 11. A 12. B (enzyme = catalyst) 13. C (more OH- ions makes a substance more basic) 14. B 15. About 45 degrees Celsius 16. X 17. C (polymer made of monomers) 18. C 19. B 20. A 21. B 22. A (maltose is clearly the substrate) 23. B (breaking substrate down) 24. B 25. D (stomach is the only organ listed where food passes through)