1Chapter 2: The Molecular Composition of Plant CellsMultiple-Choice Questions1. Introduction; p. 18; easy; ans: eWhich substance makes up more than half of all living matter and more than 90 percent of the weight of most plant tissues?a. Proteinb. Cellulosec. Starchd. Triglyceridee. Water2. Carbohydrates; p. 19; easy; ans: bThe most abundant organic molecules in nature are:a. proteins.b. carbohydrates.c. lipids.d. nucleic acids.e. water molecules.3. Carbohydrates; p. 19; easy; ans: a _________ is a monosaccharide, and ______________ is a disaccharide.a. Fructose; lactoseb. Maltose; ribosec. Cellulose; sucrosed. Sucrose; glucose e. Maltose; lactose4. Carbohydrates; p. 19; easy; ans: e________ is composed of two sugar subunits linked covalently.a. Celluloseb. Fructosec. Ribosed. Glucosee. Sucrose5. Carbohydrates; p. 19; moderate; ans: aThe common transport form of sugar in plants is ______ and in animals is ______.a. sucrose; glucoseb. glucose; sucrosec. starch; sucrosed. maltose; lactosee. fructose; maltose6. Carbohydrates; p. 20; moderate; ans: eThe formation of ______ from ______ occurs by dehydration synthesis.a. glucose and fructose; sucroseb. glucose; starchc. monomers; polymersd. glucose; cellulosee. sucrose; glucose and fructose7. Carbohydrates; p. 20; moderate; ans: bWhich of the following statements about hydrolysis reactions is FALSE?a. They are energy-yielding reactions.b. They are a type of condensation reaction.c. They involve the addition of a molecule of water.d. An example is the conversion of a polymer to its monomers.e. An example is the conversion of disaccharides to monosaccharides.8. Carbohydrates; p. 20; moderate; ans: cThe principal polysaccharide in the plant cell wall is:a. starch.b. fructan.c. cellulose.d. glycogen.e. sucrose.9. Carbohydrates; p. 20; easy; ans: aWhat is the most abundant organic compound known?a. celluloseb. sucrosec. DNAd. phospholipide. starch10. Carbohydrates; p. 21; moderate; ans: dWhich of the following consists of beta-glucose subunits?a. amyloseb. amylopectinc. chitind. cellulosee. glycogen11. Carbohydrates; pp. 21-22; moderate; ans: bThe matrix of the plant cell wall contains:a. microfibrils and pectins.b. pectins and hemicelluloses.c. hemicelluloses and oligosaccharins.d. cellulose and chitin.e. chitin and glycogen.12. Carbohydrates; p. 22; moderate; ans: eWhich stabilize the cell wall by forming hydrogen bonds with it?a. pectinsb. starchesc. chitinsd. lipidse. hemicelluloses13. Carbohydrates; p. 22; difficult; ans: bWhich comprise most of the middle lamella? a. hemicellulosesb. pectinsc. lipidsd. chitinse. starches14. Carbohydrates; p. 22; easy; ans: bThe principal component of the cell walls of fungi is:a. cellulose.b. chitin.c. starch.d. protein.e. phospholipid.15. Carbohydrates; p. 22; easy; ans: dThe monomer of ___________ is N-acetylglucoseamine.a. microfibrilsb. enzymesc. storage polysaccharidesd. chitine. fats16. Lipids; p. 22; moderate; ans: eWhen an oil undergoes hydrolysis, the products are:a. 1 amino acid and 3 glycerolsb. many glucose monomersc. 1 fatty acid and 3 glycerolsd. 1 sucrose and 3 fatty acidse. 1 glycerol and 3 fatty acids17. Lipids; pp. 22-23; easy; ans: aWhich are examples of triglycerides?a. oils and fatsb. fats and steroidsc. oils and starchesd. starches and proteinse. proteins and fats18. Lipids; pp. 22-23; difficult; ans: cA fat differs from a phospholipid in that a fat contains:a. a phosphate groupb. 1 glycerolc. 3 fatty acidsd. a steroide. a wax19. Lipids; p. 23; moderate; ans: bThe main function of cutin and suberin is to:a. serve as structural components of cellular membranes.b. prevent water loss.c. catalyze chemical reactions.d. provide strength to the cell wall.e. serve as hormones.20. Lipids; p. 23; moderate; ans; cWhich lipid is a major component of cork cell walls?a. phospholipidb. cutinc. suberind. steroide. lignin21. Lipids; pp. 23-24; difficult; ans: cWho am I? I give cell walls a lamellar appearance?a. phospholipidb. cutinc. suberind. waxe. lignin22. Lipids; p. 24; moderate; ans: bThe most water-repellant of the lipids are:a. steroidsb. waxesc. cellulosesd. suberinse. cutins23. Lipids; p. 24; easy; ans: aWhich of the following is characterized by the presence of four interconnected hydrocarbon rings? a. steroids b. lignin c. epicuticular wax d. phospholipids e. triglycerides24. Lipids; p. 24; moderate; ans: eIn all organisms except prokaryotes, an important role of sterols is to:a. serve as storage forms of energy.b. prevent water loss.c. catalyze chemical reactions.d. provide strength to the cell wall.e. stabilize the phospholipid tails in cell membranes.25. Proteins; p. 25; easy; ans: bThe monomers of proteins are:a. monosaccharides.b. amino acids.c. glycerol and fatty acids.d. nucleotides.e. fused hydrocarbon rings.26. Proteins; p. 25; easy; ans: cHow many different kinds of amino acids are used to build proteins?a. 5b. 10c. 20d. 50e. 10027. Proteins; p. 27; easy; ans: aA peptide bond occurs between the ______ groups of adjacent amino acids in polypeptides.a. amino and carboxylb. sulfhydryl c. amino and phosphated. carboxyl and hydroxyle. amino28. Proteins; p. 27; moderate; ans: bWhen a polypeptide undergoes hydrolysis, the products are:a. glycerols and fatty acidsb. amino acidsc. monosaccharidesd. nucleotidese. polysaccharides29. Proteins; p. 27; easy; ans: aThe linear sequence of amino acids is called the ______ structure of a protein.a. primary b. secondaryc. tertiaryd. quaternarye. helix30. Proteins; p. 28 and Fig. 2–16; difficult; ans: bA common ______ structure of proteins involves a hydrogen bond between the amino group of one amino acid and the carboxyl group of an amino acid farther along the peptide chain.a. primary b. secondaryc. tertiaryd. quaternarye. pentenary31. Proteins; p. 28; difficult; ans: eThe tertiary structure of a protein is a result of all of the following EXCEPT:a. the folding of the secondary structure.b. the linear sequence of amino acids.c. the formation of disulfide bridges.d. interactions among the R groups of a single polypeptide.e. interactions between two or more polypeptide chains.32. Proteins; p. 29; easy; ans: dThe ______ structure of a protein involves interactions between two or more polypeptide chains.a. primary b. secondaryc. tertiaryd. quaternarye. pentenary33. Proteins; p. 29; easy; ans: eWhich of the following statements about enzymes is FALSE?a. They are globular proteins.b. They enable cells to carry out chemical reactions at room