The Building Blocks of Life

The Building Blocks of Life Chapter Diagnostic Question 1. Which of the following particles is negatively charged? a) Electron b) Isotope c) Neutron d) Proton 2. Isotopes are created by a change in the number of what particle of an atom? a) Electrons b) Neutrons c) Protons d) Ions 3. Identify the proteins that speed up the rate of chemical reactions. a) Substrates b) Enzymes c) Ions d) Reactants 4. What particles are in an atom’s nucleus? a) Neutrons and electrons b) Protons and electrons c) Protons and neutrons 5. What causes the charge of an atom to be zero? a) An equal number of protons and neutrons b) An equal number of protons and electrons c) An equal number of neutrons and electrons 6. What type of substance is water? a) A compound b) An element c) An isotope d) A mixture 7. What provides the energy for all living processes? a) Chemical bonds b) Ionic compounds c) Radioactive isotopes d) Van der Waals forces 8. Which is a chemical reaction? a) A match burning b) Salt dissolving c) Water boiling d) Gasoline evaporating 9. Which chemical reaction is endothermic? a) b) 10. How does an enzyme increase the rate of a chemical reaction? a) It acts as a reactant. b) It reduces the amount of heat produced. c) It increases the amount of product. d) It lowers the activation energy. 11. What occurs at the active site in the enzyme substrate complex? a) An exothermic chemical reaction takes place. b) Chemical bonds are broken and new bonds are formed. c) The enzyme gets used up in the reaction. d) The substrates provide energy for the enzyme. 12. Why is water able to dissolve a wide variety of solutes? a) It acts as a catalyst. b) Its pH is neutral. c) It is a polar molecule. d) It is an ionic compound. 13. What type of bonds attracts water molecules to each other and to other substances? a) Covalent bonds b) Double bonds c) Hydrogen bonds d) Ionic bonds 14. Which ion, when released in water, causes a solution to be basic? a) 𝐶𝐼 − b) 𝑶𝑯− c) 𝐻 + d) 𝑁𝑎+ 15. What is the name for a substance that keeps the pH in cells within the 6.5 to 7.5 pH range? a) Alkali b) Antacid c) Buffer d) Neutralizer 16. Which element do almost all biological molecules contain? a) Carbon b) Nitrogen c) Phosphorus d) Sodium 17. How many covalent bonds can carbon from with other atoms? a) 1 b) 2 c) 4 d) 8 18. What type of biological molecule is an enzyme? a) Hormone b) Nucleic acid c) Protein d) Steroid 19. What are fats, oils, and waxes composed of? a) Lipids b) Nucleotides c) Polypeptides d) Sugars 20. What are the monomers that make up proteins? a) Amino acids b) Fatty acids c) Glycerol’s d) Nucleotides 21. Which biological molecule transports substances between cells? a) Carbohydrate b) Lipid c) Nucleic acid d) Protein 22. Look at the following figure. Determine what the upward curve represents. a) Activation energy b) Reactants c) Products d) Enzymes 23. Look at energy levels in the atom. What is the maximum number of electrons energy level two can hold? a) 2 b) 4 c) 6 d) 8 24. Explain why chemical equations must be balanced. Answer: Chemical reactions require balance of mass. Therefore, the number of atoms of each element on the reactant side must equal the number of atoms of the same element on the product side. 25. Which is a result of van der Waals forces? a) Atoms sharing electrons b) Table salt dissolving in water c) Ionic compounds forming crystals d) Water molecules forming droplets 26. What is true of this chemical reaction? a) Energy is not needed to start the chemical reaction. b) Heat and/or light energy are released in this reaction. c) The activation energy is greater than the energy released. d) The energy of the products and the reactants is the same. 27. Which fruit contains a higher concentration of hydrogen ions? a) Tomatoes b) Bananas 28. What do cellulose and chitin have in common? a) They are energy- storing polymers. b) They are found in the cells of animals. c) They are structural polysaccharides. d) They are composed of repeating sucrose units. 29. Which polysaccharide stores energy in muscle and liver tissue? a) Gluten b) Glycogen c) Starch d) Sucralose 30. What is the function of this biological macromolecule? a) Communicate signals between cells b) Produce vitamins and hormones c) Provide support and protection d) Store and transmit genetic information 31. Which is a characteristic of all lipids? a) They are saturated triglycerides. b) They do not dissolve in water. c) They are liquid at room temperature. d) They store less energy than carbohydrates.