Biology: Life on Earth 7e
Chapter 3: Biological Molecules
Self Test
1. Functional groups are __________.
Student Self Test Questions and Answers a. groups of atoms in organic molecules that can participate in certain types of chemical reactions b. arrangements of cells into tissues c. classes of biological molecules with similar functions d. classifications of inorganic molecules based on their reactivity
2. In chemical reactions, the molecules that take part in the reaction are called reactants.
Conversely, molecules produced by a chemical reaction are called products.
During the process of polymerization (synthesis of biological polymers), water is a __________, and the reaction is consequently called a __________ reaction. a. reactant, dehydration b. reactant, hydrolysis c. by-product, dehydration d. product, hydrolysis
3. Carbohydrates are a class of biological molecules that include __________. a. sugars and polymers of sugars b. ring-shaped molecules that are soluble in water c. monosaccharides, disaccharides, and polysaccharides d. components of DNA and RNA e. All of the above.
4. The general class of biological molecules that contains large, nonpolar regions that make these molecules insoluble in water is called __________. a. phospholipids b. fats c. lipids d. waxes
5. Saturated fats __________. a. have no double covalent bonds b. are solid at room temperature c. contain the maximum number of hydrogen atoms possible d. Both the first and second answers above are correct. e. The first, second, and third answers above are correct.
6. Phospholipids contain a "head group" that is _________ and two fatty acid "tails" that are __________. a. hydrophobic, hydrophilic b. hydrophilic, hydrophobic c. hydrolyzed, nonhydrolyzed d. hydrophilic, hydrophilic
7. Proteins are polymers of __________. a. peptides b. amino acids c. nucleotides d. sugars
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Biology: Life on Earth 7e
8. Protein functions in cells include __________. a. storage and defense b. catalysis of biochemical reactions c. structure and movement d. transport and defense e. all of the above
Student Self Test Questions and Answers
9. A nucleotide is composed of __________. a. a sugar and a phosphate group b. a phosphate group and a nitrogen-containing base c. a sugar and a nitrogen-containing base d. a sugar, a phosphate group, and a nitrogen-containing base
10. Imagine that you see a diagram of molecular structures in which the atoms are shown as dots and covalent bonds are shown as lines between the dots. The molecules in the diagram have a variety of complex shapes, including long chains, branched chains, rings, and combinations of chains and rings. What type of molecules are these and what is the key atom in them? a. The complex structures of these molecules indicate that they are organic molecules and, therefore, contain carbon. b. The complex structures of these molecules indicate that they are inorganic molecules and, therefore, do not contain carbon. c. The complex structures of these molecules indicate that they are organic molecules and, therefore, do not contain carbon. d. The complex structures of these molecules indicate that they were created in a laboratory and, therefore, contain unnatural atoms.
11. At the gym one day, you notice a new "Energy Bar" being sold that advertises quick energy for your workout. To impress you further, it is claimed this bar contains only carbon, oxygen, and hydrogen atoms. What kind of biological molecule(s) would you be eating if you ate an "Energy Bar"? a. proteins and fats b. proteins c. DNA and RNA d. lipids e. carbohydrates
12. A scientist is studying the metabolism of proteins in yeast and wants to follow the formation of proteins from the earliest possible point. In her experiment, she will feed the yeast radioactive nutrients and follow the fate of the radioactivity in the cells. Which of the following atoms will allow her to exclusively follow proteins in the cell? a. radioactive carbon b. radioactive nitrogen c. radioactive oxygen d. radioactive sulfur
13. How are large organic molecules (macromolecules) synthesized? a. by hydrolysis of monomers b. by hydrolysis of polymers c. by a dehydration reaction utilizing monomers d. by a dehydration reaction utilizing polymers
14. Carbohydrates __________.
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Biology: Life on Earth 7e Student Self Test Questions and Answers a. can exist as monomers (monosaccharides), dimers (disaccharides), and polymers
(polysaccharides) b. have the general chemical formula of (CH
2
O) n c. can function as a source of energy or can function as an extremely durable structural material, depending upon the specific nature of their chemical bonds between subunits (monomers) d. all of the above
15. A cell membrane is primarily composed of __________. a. oils, which are liquid at room temperature b. saturated fats c. phospholipids d. steroids
16. Proteins are macromolecules that can perform many different functions within an organism. This diversity of function for this macromolecule is due to the unique nature of one of its four functional groups that is bound to a central carbon atom. Which functional group is responsible for the wide diversity of function attributed to proteins? a. the carboxyl group b. the amino group c. a hydrogen atom d. the R group
17. The quaternary level of protein structure __________. a. refers to a functional (biologically active) complex of two or more three-dimensional proteins
(e.g., hemoglobin) b. is demonstrated by the three-dimensional organization of a single polypeptide c. refers to the serial sequence, or arrangement, of amino acids that make up a protein d. none of the above
18. Nucleotides __________. a. are composed of a sugar, a salt, and a phospholipid b. are found only in nucleic acids, the molecules responsible for passing genetic information from generation to generation c. are found in nucleic acids, intracellular messenger molecules, and high-energy molecules d. Both the first and second answers above are correct.
19. All of the following are polysaccharides except __________. a. cellulose b. starch c. glycogen d. glucose
20. You have identified a protein that is unable to form disulfide bridges. This would affect which of the following? a. primary structure of the protein b. secondary structure of the protein c. tertiary structure of the protein d. dehydration synthesis
21. All of the following are proteins except __________.
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Biology: Life on Earth 7e a. cholesterol b. enzymes c. antibodies d. All of the above are proteins.
Student Self Test Questions and Answers
22. What types of biological molecules transport fat molecules through the human bloodstream? a. complex carbohydrates b. cholesterol c. phopholipids d. lipoproteins
23. Which of the following is not found in DNA? a. adenine b. guanine c. uracil d. cytosine e. thymine
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