Ch. 5 The Structure and Function of Large Biological Molecules
Which of the following statements is true regarding the molecule illustrated in Figure 5.2?
It is a saturated fatty acid, a diet rich in this molecule may contribute to atherosclerosis
Which of the following statement is/are true regarding the chemical reaction illustrated in Figure 5.5?
It results in a peptide bond
For this pair of items, choose the option that best describes their relationship. (A) the probability of finding chitin in fungal cell walls (B) The probability of finding chitin in arthropod exoskeletons
Item (A) is exactly or very approximately equal to item (B)
For this pair of items, choose the option that best describes their relationship
Item (A) is greater than item (B)
For this pair of items, choose the option that best describes their relationship. (A) The probability that amino acids with nonpolar side chains are hydrophobic. (B) The probability that amino acids with side chains containing a carboxyl group are hydrophobic.
Item (A) is greater than item (B)
For this pair of items, choose the option that best describes their relationship. (A) The number of cis double bonds in saturated fatty acids (B) The number of cis double bonds in unsaturated fatty acids
Item (A) is less than item (B)
For this pair of items, choose the option that best describes their relationship. (A) The number of alpha glucose 1-4 linkages in cellulose (B) The number of alpha glucose 1-4 linkages in starch
Item (A) is less than item (B)
Roger Kornberg used this method for elucidating the structure of RNA polymerase
X-ray crystallography
What is a triacylgylcerol?
a lipid made with three fatty acids and glycerol
Which of the following descriptions best fits the class of molecules known as nucleotides?
a nitrogenous base, a phosphate group, and pentose sugar
Large organic molecules are usually assembled by polymerization of a few kinds of simple subunits. Which of the following
a steroid
What method did Frederick Sanger use to elucidate the structure of insulin
analysis of amino acid sequence of small fragments
Polysaccharides, lipids, and proteins are similar in that they
are synthesized from monomers by dehydration reactions
Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified?
as a disaccharide
Which of the following uses the amino acid sequences of polypeptides to predict a protein's three-dimensional structure?
bioinformatics
A molecule with the chemical formula C₆H₁₂O₆ is probably a
carbohydrate, lipid, and monosaccharide
On food packages, to what does the term "insoluble fiber" refer?
cellulose
What is the term used for a protein molecule that assists in the proper folding of other proteins?
chaperonin
Which of the following polymers contain nitrogen?
chitin
All of the following contain amino acids except
cholesterol
What is the structural feature that allows DNA to replicate?
complementary pairing of the nitrogenous bases
The difference between the sugar in DNA and the sugar in RNA is that the sugar in DNA
contains one less oxygen atom
Which of the following are nitrogenous bases of the pyrimidine type?
cytosine and uracil
What is the chemical mechanism by which cells make polymers from monomers?
dehydration reactions
The function of each protein is a consequence of its specific shape. What is the term used for a change in a protein's three-dimensional shape or conformation due to disruption of hydrogen bonds, disulfide bridges, or ionic bonds?
denaturation
There are 20 different amino acids. What makes one amino acid different from another?
different side chain (R groups) attached to an alpha carbon
A strong covalent bond between amino acids that functions in maintaining a polypeptide's specific three-dimensional shape is a (an)
disulfide bond
a molecule with the formula C₁₈H₃₆O₂ is probably a
fatty acid
Of the following functions, the major purpose of RNA is to
function in the sythesis of protein
Which of the following is not a polymer?
glucose
All of the following are polysaccharides except
glycogen
The enzyme amylase can break gylcosidic linkages between glucose monomers only if the monomers are the a form. Which of the following could amylase break down?
glycogen
In the double helix structure of nucleic acids, cytosine hydrogen bonds to
guanine
Which of the following are nitrogenous bases of the purine type?
guanine and adenine
Which of the following descriptors is true of the molecules shown in Figure 5.1?
hexose and glucose
Human can digest starch but not cellulose because
human have enzymes that can hydrolyze the alpha glycosidic linkages of starch but not the beta glycosidic linkages of cellulose
Which type of interaction stabilizes the alpha helix and the beta pleated sheet structures of proteins?
hydrogen bonds
A new organism is discovered in the forests of Costa Rica. Scientists there determine that the polypeptide sequence of hemoglobin from the new organism has 72 amino acid differences from humans, 65 differences from a gibbon, 49 differences from a rat, and 5 differences from a frog. These data suggest that the new organism
is more closely related to frogs than to humans
Which of the following is true of cellulose?
it is a major structural component of plant cell walls
Which of the following is a diverse group of hydrophobic molecules?
lipids
If 2 molecules of the general type in Figure 5.1 were linked together, carbon 1 of the molecule to carbon 4 of the other, the single molecule that would result would be
maltose
Which of the following statements is true regarding the molecule illustrated in Figure 5.3?
molecules of the type are usually liquid at room temperature
The element nitrogen is present in all of the following except
monosaccharides
Which of the following store and transmit hereditary information?
nucleic acids
Altering which of the following levels of structural organization could change the function of a protein?
primary, secondary, tertiary, quaternary
Enzymes are
proteins
The bonding of two amino acid molecules to form a larger molecule requires which of the following?
removal of a water molecule
The hydrogenation of vegetable oil results in which of the following?
saturated fats and unsaturated fat with trans double, an increased contribution to atherosclerosis, and the oil (fat) being a solid at room temperature
The alpha helix and the pleated sheet are both common polypeptide forms found in which level of protein structure?
secondary
What is the structure shown in Figure 5.4?
steroid molecule
At which level of protein structure are interactions between the side chains (R groups) most important?
tertiary
Which of the following statements about 5' end of a polynucleotide strand of DNA is correct?
the 5' end has a phosphate group attached to the number 5 carbon of ribose
DNAase is an enzyme that catalyzes the hydrolysis of the covalent bonds that join nucleotides together. What would first happen to DNA molecules treated with DNAase?
the phosphodiester bonds between deoxyribose sugars would be broken
What would be an unexpected consequence of changing one amino acid in a protein consisting of 325 amino acids?
the primary structure of the protein would be changed, the tertiary structure of the protein might be changed, the biological activity or function of the protein might be altered
Which of the following is an example of hydrolysis?
the reaction of a fat, forming glycerol and fatty acids with the utilization of water
The bonding of two amino acid molecules to form a larger molecule requires
the release of a water molecule
Which of the following is true of both starch and cellulose
they are both polymers of glucose
Which of the following statements is false for the class biological molecules known as lipids?
they are soluble in water
Why are sex hormones considered to be lipids?
they are steroids, which are not soluble in water
Which of the following is true regarding saturated fatty acids?
they are the principal molecules in lard and butter
All of the following statements concerning saturated fats are true except
they have multiple double bonds in the carbon chains of their fatty acids
Dehydration reactions are used in forming which of the following compounds?
triacyglycerides, polysaccharides, proteins
The tertiary structure of a protein is the
unique three-dimensional shape of the fully folded polypeptide
The molecule shown in Figure 5.3 is a
unsaturated fatty acid
How many molecules of water are needed to completely hydrolyze a polymer that is 11 monomers long?
10
A double-stranded DNA molecule contains a total of 120 purines and 120 pyrimidines
120 thymine and 120 adenine molecules
How many different kinds of polypeptides, each composed of 12 amino acids, could be synthesized using the 20 common amino acids?
20¹²
If one strand of a DNA molecule has the sequence of bases 5' ATTGCA 3', the other complementary strand would have the sequence
3'TAACGT5'
If a DNA sample were composed of 10% thymine, what would be the percentage of guanine?
40
Upon chemical analysis, a particular polypeptide was found to contain 100 amino acids. How many peptides bonds are present in this protein?
99
The R group or side chain of the amino acid serine is -CH₂-OH. The R group or side chain of the amino acid alanine is -CH₃. Where would you expect to find these amino acids in a globular protein in aqueous solution?
Alanine would be in the interior, and serine would be on the exterior of the globular protein
Misfolding of polypeptides is a serious problem in cells. Which of the following diseases are associated with an accumulation of misfolded proteins?
Alzheimer's, Parkinson's
The molecular formula for glucose is C6H12O6. What would be the molecular formula for a molecule made by linking three glucose molecules together by dehydration reactions?
C₁₈H₃₀O₁₅
Which of the following statements best summarizes the structural differences between DNA and RNA?
DNA nucleotides contain a different sugar than RNA nucleotides
Which of the following best describes the flow of information in eukaryotic cells?
DNA→RNA→proteins
Which of the following best summarizes the relationship between dehydration reactions and hydrolysis?
Dehydration reactions assemble polymers, and hydrolysis reactions break down polymers and macromolecular synthesis occurs through the removal of water and digestion occurs through the water
