\( \qquad \) 9 Which statement about enzymes is false? a) Enzymes are organic catalysts b) Enzymes are Composed mostly of protein c) Enzymes raise the activation energy needed to start a reaction d) Enzymes may be damaged by high temperature \( \qquad \) 10. Which of the following is true regarding the concentration of solutions a) To calculate molarity one must know the atomic number of the solute b) Molarity is one mole of solute per 1000 ml of solution c) To calculate molarity, one must know the atomic weight of the solvent.d) percent solutions are parts per 1000 parts \( \qquad \) 11. Many plasma proteins may function as \( \qquad \) . a) Buffers b) antibodies c) structural proteins d) oxygen transport vesicles \( \qquad \) 12. The ATP molecule is not used in \( \qquad \) . a) Pigment b) mechanical work c) transport d) chemical work \( \qquad \) 13. Select the most correct statement regarding nucleic acids. a) Three forms exist DNA, RNA, and tDNA b) TDNA is considered a molecular servant of DNA c) RNA is a long single-stranded molecule made up of the bases A,T,G, and C. d) DNA is a long double stranded molecule made up of \( A, T, G \), and \( C \) bases \( \qquad \) 14. \( \qquad \) is a suspension. a) Blood b) rubbing alcohol c) saltwater d) cytoplasm \( \qquad \) 15. Select the correct statement about isotopes. a) Isotopes occur only in the heavier elements b) Isotopes of the same element have the same atomic number but differ in their atomic mass. c) all of the isotopes of an element are radioactive d) all the isotopes of an element have the same number of neutrons \( \qquad \) 16. The four elements that make up about \( 96 \% \) of body matter are \( \qquad \) . a) Cárbon,oxygen,hydrogen, nitrogen b) carbon, oxygen, phosphorus,calciúm c) nitrogen, hydrogen, calcium, sodium d) sodium, potassium, hydrogen,oxygen \( \qquad \) 17. \( \qquad \) is fat-soluble, produced in the skin on exposure to UV radiation, and necessary for normal bone growth and function. a) Vitamin A b) Vitamin D c) Vitamin K d) Cortisol \( \qquad \) 18, In liquid \( X Y Z \), you notice that light is scattered as it passes thru. There is no precipitant in the bottom of the beaker, though it has been sitting for several days. This liquid must be a \( \qquad \) a). Solution b) colloid c) mixture d) suspension \( \qquad \) 19. Atom \( X \) has seventeen protons,. How many valence electrons would it have ? a) 10 , b) 7 c) 5 d) 3 \( \qquad \) 20. If an atom were to have two protons, then it would \( \qquad \) . a) be very stable