front 1 Carbohydrates, more commonly known as sugars, are made up of carbon, oxygen, and hydrogen atoms. The smallest unit of a carbohydrate is a monosaccharide. Two monosaccharides make up a disaccharide, and many monosaccharides make up a polysaccharide. Disaccharides and polysaccharides can be hydrolyzed back into the individual monosaccharide units. Select the statement that is incorrect.: A. Complex sugars are carbohydrates. B. All carbohydrates have the general formula Cn(H2O)n. C. Simple sugars are carbohydrates. D. Simple sugars contain only carbon, oxygen, and hydrogen atoms. | back 1 B. All carbohydrates have the general formula Cn(H2O)n. |
front 2 Glycogen is _____. A. a polysaccharide found in plant cell walls B. a transport protein that carries oxygena source of saturated fat C. a polysaccharide found in animals the form in which plants store sugars D. a source of saturated fat E. the form in which plants store sugars | back 2 C. a polysaccharide found in animals the form in which plants store sugars |
front 3 Which of these is a polysaccharide? A. glucose B. sucrose C. lactose D. galactose E. cellulose | back 3 E. cellulose |
front 4 Which of these is NOT a lipid? A.phospholipid B.RNA C.cholesterol D.steroids E.wax | back 4 B.RNA |
front 5 A function of cholesterol that does not harm health is its role _____. A. as a component of animal cell membranes B. All of cholesterol's effects cause the body harm. C. as the primary female sex hormone D. the most abundant male sex hormone E. in calcium and phosphate metabolism | back 5 A. as a component of animal cell membranes |
front 6 Which polymers are composed of amino acids? A. Nucleic acids B. Carbohydrates C. Proteins D. Monomers | back 6 C . proteins |
front 7 Which of the following is not attached to the central carbon atom in an amino acid? A. An oxygen B. A side chain ("R group") C. An amino functional group D. A carboxyl functional group | back 7 A. An oxygen |
front 8 Which monomers make up RNA? A. Polymers B. Nucleotides C. Simple sugars D. Amino acids | back 8 B. Nucleotides |
front 9 Which of the following statements about the formation of polypeptides from amino acids is true? A. A bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid. B. Polypeptides form by condensation or hydrolysis reactions. C. The reaction occurs through the addition of a water molecule to the amino acids. D. A bond can form between any carbon and nitrogen atom in the two amino acids being joined. | back 9 A. A bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid. |
front 10 The organic molecule called DNA is an example of .... A. a polymer made of amino acids. B. a polymer made of nucleotes. C. a polymer made of nucleotides. D. a protein. E. a monomer. | back 10 C. a polymer made of nucleotides. |
front 11 Which molecule is not a carbohydrate? A. Lipid B. Starch C. Glycogen D. Cellulose | back 11 A. Lipid |
front 12 Which of the following statements about monosaccharide structure is true? A. All monosaccharides contain carbon, hydrogen, oxygen, and nitrogen atoms. B. Aldoses and ketoses differ in the position of their hydroxyl groups. C. A six-carbon sugar is called a pentose. D. Monosaccharides can be classified according to the spatial arrangement of their atoms. | back 12 D. Monosaccharides can be classified according to the spatial arrangement of their atoms. |
front 13 Which of the following complex carbohydrates is listed with its correct function? A. Cellulose: structural component of plant cell walls B. Chitin: constituent of bacterial cell walls C. Starch: primary energy-storage molecule in animals D. Amylose: main component of plant starch | back 13 A. Cellulose: structural component of plant cell walls |
front 14 Which polysaccharide contains a modified monosaccharide? A. Peptidoglycan B. Glycogen C. Starch D. Cellulose | back 14 A. Peptidoglycan |
front 15 Polymers that contain sugars ... A. (a) may store hereditary information. B. (b) may store energy. C. (c) may protect cells.Both D. (b) and (c). E. (a), (b), and (c). | back 15 E. (a), (b), and (c). |
front 16 Which statement is true of sucrose?
(b) It contains glucose. (c) It's table sugar .Both (a) and (c) .(a), (b), and (c). | back 16 .(a), (b), and (c). |
front 17 Dr. Haxton told one of his students, "To move in the bloodstream, fats need the help of phospholipids." What would a good student say? A. Yes. Nonpolar molecules aren't compatible with water. B. Sorry, Dr. Haxton! Help comes from cholesterol, not phospholipids C. Not so. Fats are small enough to travel easily without help. D. You have it backwards. Fats help phospholipids to travel E. Right. Fats are too polar to travel alone in water. | back 17 A. Yes. Nonpolar molecules aren't compatible with water. |
front 18 The presence of many C-C and C-H bonds causes fats to be ... (a) rich in energy. (b) insoluble in water. (c) low in energy. Both (a) and (b). Both (b) and (c). | back 18 Both (a) and (b). |
front 19 In fat synthesis,________and fatty acids combine to make fats plus________. A. phosphate; glycerol B. glucose; phosphate C. esters; water D. glycerol;water E. esters; phosphate | back 19 D. glycerol; water |
front 20 In the reaction that builds a fat,________ groups react with ________ groups. A. sulfhydryl; carboxyl B. hydroxyl; phosphate C. phosphate; amino D. hydroxyl; carboxyl E. carboxyl; amino | back 20 D. hydroxyl; carboxyl |
front 21 Triglycerides vary with respect to the number of ... (a) hydrocarbon tails. (b) C atoms in the tails. (c) double bonds in the tails. Both (b) and (c). All of the above. | back 21 Both (b) and (c). |
front 22 A food company hydrogenated a barrel of fat. The treatment ... (a) made the fat less fluid. (b) made the fat less saturated. (c) lengthened the fat tails. (d) put more bends (kinks) in the fat tails. Both (a) and (d). | back 22 (a) made the fat less fluid. |
front 23 The most unsaturated fats have ... A. the longest hydrocarbon tails. B. the fewest double bonds. C. the most double bonds. D. the highest ratio of H to C. E. the shortest hydrocarbon tails. | back 23 C. the most double bonds. |
front 24 What do DNA, proteins, and fats have in common? A. They contain nitrogen. B. They are polymers. C. They are polar. D. They contain phosphorus. E. They contain carbonyl groups. | back 24 E. They contain carbonyl groups. |
front 25 Phospholipids are most important for ... | back 25 preventing leakage from cells. |
front 26 To find the best source of phospholipids, look at ... A. cell walls. B. nasal mucus. C. membranes. D. surfaces of leaves. E. storage droplets. | back 26 C. membranes. |
front 27 What do phosphoglycerides and fats have in common? A. A strongly polar group. B. A tendency to form bilayers. C. Ester linkages. D. A role in membrane structure. E. Three fatty acid tails. | back 27 C. Ester linkages. |
front 28 Which statement is true of phospholipids? (a) Their synthesis uses fatty acids. (b) Some of their tails have double bonds. (c) They all ionize. All the above. Both (a) and (b). | back 28 All the above. |
front 29 Which fact is most important in causing phospholipids to behave as they do in water? A. Hydrocarbons attract one another. B. Nonpolar groups repel water C. Phosphate groups can bind together. D. Hydrogen is more electronegative than oxygen. E. Water molecules make hydrogen bonds. | back 29 E. Water molecules make hydrogen bonds. |
front 30 In a membrane, the________of the phospholipids in one monolayer face the________of the phospholipids in the other monolayer. | back 30 (c) tails; tails |
front 31 It is difficult for molecules to pass through the phospholipid bilayer because ... A. hydrocarbons repel water. B. polar molecules attract one another. C. proteins hold phospholipids in place. D. cholesterol holds phospholipids in place. E. there is a water film between the monolayers. | back 31 polar molecules attract one another. |
front 32 Which lipid is most amphipathic? | back 32 Phospholipid |
front 33 What does cholesterol have in common with sex hormones? Four linked rings. Strong polarity .Fatty acids. Causes heart disease. Ester linkages. | back 33 Four linked rings. |
front 34 Proteins are polymers of _____. A. nucleotides B. CH2O units C. glycerol D. hydrocarbons E. amino acids | back 34 E. amino acids |
front 35 What type of bond joins the monomers in a protein's primary structure? A. ionic B. peptide C. S - S D. hydrophobic E. hydrogen | back 35 peptide |
front 36 The secondary structure of a protein results from _____. A. hydrophobic interactions B. hydrogen bonds C. ionic bonds D. peptide bonds E. bonds between sulfur atoms | back 36 B. hydrogen bonds |
front 37 Tertiary structure is NOT directly dependent on _____. A. bonds between sulfur atoms B. hydrophobic interactions C. hydrogen bonds D. peptide bonds E. ionic bonds | back 37 D. peptide bonds |
front 38 Which biological activity does NOT directly involve proteins? A. Changing the shape of a cell. B. Defending cells against viruses. C. Breaking food polymers into smaller molecules. D. Sensing light. E. None of the above; proteins are involved in all of them. | back 38 E. None of the above; proteins are involved in all of them. |
front 39 A major limitation of the ribbon model of a protein is:
(b) It can't show the orientation of key side chains. (c) It gives a false sense of open space in the protein. Both (a) and (c). (a), (b), and (c). | back 39 (c) It gives a false sense of open space in the protein. |
front 40 The human myoglobin protein contains 153 amino acids. If you take one guess at the amino acid sequence, what is your chance of being right? One chance in 20x153. One chance in 153. One chance in 15320. One chance in 18153. One chance in 20153. | back 40 One chance in 20153. |
front 41 A biochemist modified a protein so the amino acid lysine occurred where the amino acid aspartic acid previously occurred. This change could ... a) alter the protein's secondary structure without affecting the primary structure. (b) alter the protein's tertiary structure. (c) affect the protein's backbone. Both (b) and (c). (a), (b), and (c). | back 41 (b) alter the protein's tertiary structure. |
front 42 Identify the empirical formula of a free amino acid whose side chain is just H. A. C2H5O2N B. C2H5ON C. CH6O2N D. C2H4O2N E. NONE OF The ABOVE | back 42 A. C2H5O2N |
front 43 A certain amino acid side chain ionizes at low pH but not at very high pH. What else is true of this side chain? A. It donates H+ to water at low pH B. It is acidic. C. It contains an amino group D. It is one of 7 kinds of amino acids that share this property. E. It contains a carboxyl group. | back 43 C. It contains an amino group |
front 44 In a protein, peptide bonds connect ... C-R to N-H. C=O to N-H. N-H to C-H. C=O to C-R .All the above. | back 44 C=O to N-H. |
front 45 Amino acids are called "acids" because they ... | back 45 contain carboxyl groups in the backbone part. |
front 46 A residue in the middle of a polypeptide has −CH3 as its side chain or R group. How many atoms does the residue contain? 7 9 10 12 13 | back 46 10 |