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BIO-CHEM MODULE 4 EXAM QUESTIONS WITH VERIFIED CORRECT ANSWERS
ALREADY PASSES & GRADED A+
"lactose is made from linking galactose and glucose. when this happens: a. a polysaccharide is formed b. gas is eliminated c. an epimer is formed d. an anomeric carbon is formed on carbon-
e. lactose forms by a condensation reaction - CORRECT ANSWER e. lactose forms by a
condensation reaction" "lactose is made from linking galactose and glucose. when this happens: a. gas is eliminated b. an anomeric carbon is formed on carbon- c. water is released d. an epimer is formed
e. an aldose is formed - CORRECT ANSWER c. water is released"
"which monosaccharide is not a 6-carbon monosaccharide? a. idose b. glucose c. galactose d. dihydroxyacetone
e. allose - CORRECT ANSWER d. dihydroxyacetone"
"which monosaccharide is not a 6-carbon monosaccharide? a. fructose b. ribose c. mannose d. galactose
e. glucose - CORRECT ANSWER b. ribose"
"what are the 2 monosaccharides shown below? - CORRECT ANSWER aldose (1 C2OH group)
ketose (2 C3OH groups)" "the 2 monosaccharides shown below could be best described as:
a. anomers b. aldoses c. ketoses d. epimers
e. pentoses - CORRECT ANSWER d. epimers
*epimers = D/l anomers = alpha/beta"
"what is an anomeric carbon? - CORRECT ANSWER the new chiral center formed in ring
closure; it was the carbon containing the carbonyl in the straight-chain form attached to an -OR group, -OH group, C, and H" "the polysaccharide cellulose is most chemically similar to: a. glycogen b. dextrose c. glucose d. chitin
e. starch - CORRECT ANSWER d. chitin"
"which of the following is the most common monosaccharide on earth? a. ribose b. cellulose c. chitin d. sucrose
e. glucose - CORRECT ANSWER e. glucose"
"the "D" in D-carbohydrates stands for: a. 3-dimensional b. dextrorotatory c. derivative d. design
e. double - CORRECT ANSWER b. dextrorotatory"
"which compound does not fit the formal definition of a carbohydrate? a. C6H12O
"What is the difference between amylose and amylopectin? - CORRECT ANSWER Amylose is a
linear chain of glucose joined together in alpha 1-->4 bonds in one continuous chain with no branching. These chains have a few thousand to a million glucose molecules bonded together and are referred to as the main chain. Like amylose, amylopectin has a long chain of glucose bonded together, but it also has branches every 24 to 30 glucose molecules apart from the main chain. These branches then have large numbers of residues connected by alpha 1-->4 connections. The branch points permit amylopectin to form larger compounds."
"what is the difference between epimer and anomer? - CORRECT ANSWER Epimers are
monosaccharides that differ in the orientation at only one carbon position. Anomers are the alpha and beta forms that differ only in the -OH orientation about the anomeric carbon that forms the hemiacetal group."
"polysaccharide vs. oligosaccharide - CORRECT ANSWER Polysaccharides are LONG chains of
20 or more monosaccharides joined together. Oligosaccharides consists of SHORT chains of monosaccharides joined together."
"what are Fischer projections? - CORRECT ANSWER 2D structures that represent 3D
carbohydrates or other organic molecules"
"what is a non-reducing end? - CORRECT ANSWER the end without a free anomeric carbon
that contains an o-glycosidic linkage" "Which of the following monosaccharides is a ketose? a. glucose b. fructose c. galactose
d. mannose - CORRECT ANSWER b. fructose"
"Which of the following monosaccharides is an aldose a. glucose b. galactose c. mannose d. ribose
e. all of them - CORRECT ANSWER e. all"
"Which of the following monosaccharides is a ketose? a. arabinose b. ribose c. xylose d. lyxose
e. none of them - CORRECT ANSWER e. none of them"
"The simplest aldotriose is: a. acetone b. dihydroxyacetone c. glyceraldehyde
d. threose - CORRECT ANSWER c. glyceraldehyde"
"Epimers are a. stereoisomers that differ from each other in their configuration at two or more carbon atoms. b. stereoisomers that differ from each other in their configuration at a single carbon atom. c. the α and βforms of cyclic sugars.
d. two related compounds, pyran and furan. - CORRECT ANSWER b. stereoisomers that differ
from each other in their configuration at a single carbon atom." "How many enantiomeric pairs are possible for a aldohexose? a. 2 b. 4 c. 8
d. 16 - CORRECT ANSWER c. 8"
"Sugars which differ in chirality only around one carbon are most specifically called a. anomers. b. diastereoisomers. c. enantiomers. d. epimers.
e. none of these - CORRECT ANSWER d. epimers"
"Aldoses can form which type of cyclic structure? a. Hemiacetal b. Hemiketal c. Both hemiacetal and hemiketal
d. Neither hemiacetal and hemiketal - CORRECT ANSWER a. hemiacetal"
b. glucose only c. fructose only d. galactose and glucose e. glucose and fructose
f. galactose and fructose - CORRECT ANSWER e. glucose and fructose"
"Maltose is composed of the following simple sugars: a. galactose only b. glucose only c. fructose only d. galactose and glucose e. glucose and fructose
f. galactose and fructose - CORRECT ANSWER b. glucose only"
"The difference between cellobiose and maltose is: a. one contains glucose and the other fructose b. they contain different monosaccharides c. they both contain glucose units but are connected together at different carbons d. one has an á linkage and the other a â linkage
e. there is no difference between the two - CORRECT ANSWER d. one has an á linkage and the
other a â linkage" "Which of the following is not a reducing sugar? a. glucose b. fructose c. sucrose d. maltose
e. lactose - CORRECT ANSWER c. sucrose"
"Which of the following is a disaccharide? a. sucrose b. lactose c. maltose d. cellobiose
e. all of them - CORRECT ANSWER e. all of them"
"Lactose intolerance a. arises from inability to metabolize the disaccharide lactose b. depends on a deficiency of sucrose in the diet c. is based on the composition of lactose, consisting glucose and fructose in glycosidic linkage
d. arises because lactose is a dimer of galactose - CORRECT ANSWER a. arises from inability to
metabolize the disaccharide lactose" "Which of the following disaccharides cannot be digested by mammals? a. cellobiose b. sucrose c. maltose
d. lactose - CORRECT ANSWER a. cellobiose"
"Which of the following statements associated with cellulose is false? a. It's a linear polymer of glucose. b. The glycosidic linkage is β(1 → 4). c. Hydrolysis is accomplished enzymatically by cellulase.
d. Most animals can easily digest this compound. - CORRECT ANSWER d. Most animals can
easily digest this compound." "Cellulose is indigestible to most animals because a. animals do not have the enzymes needed to hydrolyze ester linkages between the monomer units b. animals do not have the enzymes needed to hydrolyze the α-glycosidic linkages between the monomer units c. animals do not have the enzymes needed to hydrolyze the β-glycosidic linkages between the monomer units
d. its molecular weight is too high for it to be degraded by enzymes - CORRECT ANSWER c.
animals do not have the enzymes needed to hydrolyze the β-glycosidic linkages between the monomer units" "Humans are not able to digest cellulose as a food source because: a. Cellulose is very insoluble. b. It is more important that the cellulose is used as fiber in our bodies. c. We lack the enzyme to break the βlinkage in the cellulose. d. Cellulose is insoluble and we lack the enzyme to break the βlinkage in the cellulose.
e. All of these are reasons why we cannot digest cellulose. - CORRECT ANSWER d. Cellulose is
insoluble and we lack the enzyme to break the βlinkage in the cellulose." "In bacterial cell walls a. polysaccharides form nonspecific mixtures with proteins b. polysaccharides are hydrogen bonded together c. peptides form crosslinks between polysaccharides
d. oligosaccharides form crosslinks between proteins - CORRECT ANSWER c. peptides form
crosslinks between polysaccharides"
b. False - CORRECT ANSWER a. True"
"Glycogen is sometimes called animal starch a. True
b. False - CORRECT ANSWER a. true"
"Plant starch includes amylopectin and cellulose a. True
b. False - CORRECT ANSWER b. False"
"A bacterial cell wall is composed of: a. A polysaccharide consisting of a single type of monosaccharide unit and cross-linking oligopeptides. b. A polysaccharide consisting of 2 types of monosaccharide units and cross-linking oligopeptides. c. A polysaccharide consisting of 3 types of monosaccharide units and cross-linking oligopeptides.
d. Two different polysaccharides and 1 type of oligopeptide, which are cross-linked. - CORRECT
ANSWER b. A polysaccharide consisting of 2 types of monosaccharide units and cross-linking
oligopeptides." "There are two forms of starch: a. amylose and glycogen, both of which are highly branched polysaccharides b. glycogen and chitin, both of which are linear polysaccharides c. amylopectin and glycogen, both of which are linear polysaccharides
d. amylose, which is a linear polysaccharide, and amylopectin, which is highly branched -
CORRECT ANSWER d. amylose, which is a linear polysaccharide, and amylopectin, which is
highly branched" "The blue color in a well-known test for the presence of starches is due to a. the formation of crosslinks between molecules of starch, caused by the addition of Cu2+ b. the reaction of the silver-ammonia complex ion with the hydroxyl groups of the starch c. the formation of a complex between iodine and amylose
d. none of these - CORRECT ANSWER c. the formation of a complex between iodine and
amylose" "Amino or acid derivatives of sugars are very important in which of the following biological functions? a. Structural roles b. Lubricating fluids c. Cell surface sugars used in cell identity d. Both structural roles and lubricating fluids.
e. All of the above are functions of amino and acid sugar derivatives. - CORRECT ANSWER e. All
of the above are functions of amino and acid sugar derivatives." "Cell walls a. occur in plants, animals, and bacteria b. are found in plants and bacteria, but have different chemical compositions c. have the same chemical composition in plants and bacteria
d. have the same chemical composition in plants and animals - CORRECT ANSWER b. are
found in plants and bacteria, but have different chemical compositions" "One major difference between bacterial and plant cell walls is that bacterial cell walls have polysaccharides that are crosslinked by peptides. a. True
b. False - CORRECT ANSWER a. True"
"Insoluble fiber in the diet is better at binding toxic substances than soluble fiber. a. True
b. False - CORRECT ANSWER b. false"
"The most common biopolymer on earth is this carbohydrate: a. Glucose b. Cellulose c. Starch d. Chitin
e. None of these carbohydrates is very common - CORRECT ANSWER b. Cellulose"
"Insoluble fiber in the diet is better at better at providing bulk and stimulating peristaltic action than soluble fiber. a. True
b. False - CORRECT ANSWER a. True"
"Polysaccharides used in cell wall structure contribute rigidity to the wall due to covalent cross- linking between the fibers. a. True
b. False - CORRECT ANSWER b. false"
"Chitin, which forms the exoskeletons of insects, is composed of a. α(1−4) linked N-acetylglucosamine residues
a. the presence or absence of a certain protein sequence. b. the presence or absence of a certain sugar. c. the presence or absence of an acetyl group on a sugar.
d. all of these - CORRECT ANSWER b. the presence or absence of a certain sugar."
"Which of the following is true about the ABO blood groups? a. all three of the blood groups have an á-L-fucose group attached b. type O blood is the universal donor because it has an á-L-fucose group c. type A blood has a â-N-acetylgalactosamine group
d. type AB blood is the universal donor - CORRECT ANSWER a. all three of the blood groups
have an á-L-fucose group attached" "Which of the following types of carbohydrates are made up of sugars linked by glycosidic bonds? a. Monosaccharides b. Aldoses c. Oligosaccharides
d. Ketoses - CORRECT ANSWER c. Oligosaccharides"
"The preferred energy source of the brain is __________. A) Fructose B) Glucose C) Arabinose D) Maltose
E) Sucrose - CORRECT ANSWER B"
"12) The two most common deoxy sugars are deoxyribose and _________. A) L-Fucose B) Deoxyglucose C) Deoxyarabinose D) L-Sorbose
E) D-Sorbose - CORRECT ANSWER A) L-Fucose"
"Which of the following sugars contains a -1,4-linkage? A) Cellulose B) Glucose C) Amylose D) Sucrose
E) Maltose - CORRECT ANSWER A) Cellulose"
"Oligosaccharides usually contain between ________ and ______simple sugar units. A) 6, 8
B) 2, 10
C) 1, 10
D) 3, 10
E) 7, 10 - CORRECT ANSWER B) 2, 10"
"Amylopectin is a form of ________. A) Cellulose B) Lactose C) Starch D) Glycogen
E) Amylose - CORRECT ANSWER C) Starch"
"The most abundant organic substance on earth is ______. A) Starch B) Cellulose C) Sucrose D) Glucose
E) Both B and D are correct - CORRECT ANSWER B) Cellulose"
"Which of the following is not a homoglycan? A) Cellulose B) Glycogen C) Starch D) Heparin
E) Amylose - CORRECT ANSWER D) Heparin"
"Which of the following polysaccharides can bind exceptionally large amounts of water? A) Cellulose B) Glycogen C) Starch D) Heparin
E) Amylose - CORRECT ANSWER D) Heparin"
"Carbohydrate is thought to enhance the stability of protein molecules by: A) Changing the protein's shape to better resist denaturation. B) Protecting the underlying protein from the action of proteolytic enzymes C) Using hydrogen bonding to increase the stability of the protein D) Both A and B are correct
E) All of the above are correct - CORRECT ANSWER B) Protecting the underlying protein from
the action of proteolytic enzymes"
D) A form of plant starch
E) Both C and D are correct - CORRECT ANSWER B) Main carbohydrate reserve of animals"
"Lactose intolerance arises from A) Bacteria in the intestine that produce toxic metabolites B) The inability of intestinal enzymes to cleave the lactose C) A sensitivity to galactose D) A sensitivity to glucose
E) An allergic reaction to glucose - CORRECT ANSWER B) The inability of intestinal enzymes to
cleave the lactose" "Glycoconjugates result from the covalent linkage of carbohydrate to proteins or
A) Amino acids B) Lipids C) Nucleotides D) Both A and B are correct
E) None of the above is correct - CORRECT ANSWER B) Lipids"
"The three most common homoglycans found in nature are cellulose, starch, and __________. A) Amylose B) Lactose C) Fructose D) Glycogen
E) Sucrose - CORRECT ANSWER D) Glycogen"
"29) The two polysaccharides used to store glucose as an energy reserve are starch and _____________. A) Glycogen B) Cellulose C) Fructose D) Sucrose
E) Maltose - CORRECT ANSWER A) Glycogen"
"The principal structural carbohydrate of plants is _________ A) Starch B) Glycogen C) Cellulose D) Amylose
E) Xylulose - CORRECT ANSWER C) cellulose"
"The accumulation of AGEs is linked to which of the following diseases? A) Atherosclerosis B) Arthritis C) Diabetes D) Both A and B are correct
E) All of the above are correct - CORRECT ANSWER E) All of the above are correct"
"N-Glycans are linked via a ______ link between the carbohydrate and the amino acid. A) alpha-Glycosidic B) beta-Glucosidic C) Ester D) Amide
E) Both A and B are correct - CORRECT ANSWER B) beta-Glucosidic"
"33) Which of the following is not a common sugar found in N-glycans? A) Mannose B) Glucose C) Maltose D) Fucose
E) Galactose - CORRECT ANSWER C) Maltose"
"Which of the following is an example of posttranslational modification of proteins? A) Phosphorylation B) Acetylation C) Proteolytic cleavage D) Glycosylation
E) All of the above are examples of posttranslational modification - CORRECT ANSWER E) All
of the above are examples of posttranslational modification" "The glycome is A) The total set of sugars and glycans that an organism produces B) The total set of sugars that an organism produces C) The total set of glycans that an organism produces D) The glycoforms produced by a single sugar
E) None of the above is correct - CORRECT ANSWER A) The total set of sugars and glycans that
an organism produces" "The production of the glycan components of each type of glycoprotein as a series of slightly different forms is referred to as A) Glycoformation B) Glycolation C) Microheterogeneity
B) Savory C) Sour D) Salty
E) A and B - CORRECT ANSWER A) Sweet"
"Savory taste detects which of the following? A) Sugars B) Amino acids C) Toxicity D) Electrolytes
E) Acids - CORRECT ANSWER B) Amino acids"
"44) Glycomics is defined as: A) Investigation of the structure and function of all glycans in a cell. B) Glycosidology C) Glycology D) Lipology
E) Saccariology - CORRECT ANSWER A) Investigation of the structure and function of all
glycans in a cell." "In an aldohexopyranose how many methyl groups will be incorporated on treatment with methyl iodide? A) One B) Two C) Three D) Four
E) Five - CORRECT ANSWER E) Five"
"Which of the following sugars lacks a chiral center A) Glucose B) Glyceraldehyde C) Dihydroxyacetone D) Ribose
E) Fructose - CORRECT ANSWER C) Dihydroxyacetone"
"Is the following molecule an aldose or ketose, briefly explain. - CORRECT ANSWER ketose.
There is a C=O on the third carbon from the top." "Which carbon in erythrose would tell you if the monosaccharide is D or L? Give the carbons
number in your answer. - CORRECT ANSWER On carbon 3, which is the penultimate carbon"
"Glucose and mannose are epimers. Name another epimer of glucose besides mannose. -
CORRECT ANSWER galactose"
"Is the following structure a D or L carbohydrate? Briefly explain. - CORRECT ANSWER L. The -
OH group is on the left side on the penultimate carbon."
"Does the compound C7H14O8 fit the formal definition of a carbohydrate? Explain. - CORRECT
ANSWER No. This compound has does not fit the formula CnH2nOn as indicated in the module.
There is one additional oxygen in this compound."
"Which of the following is carbon number 3? (Indicate by the appropriate letter.) - CORRECT
ANSWER C"
"Which carbon in this molecule is the anomeric carbon? (Indicate by the appropriate letter.) -
CORRECT ANSWER A"
"Is the following a furan or pyran ring? Briefly explain. - CORRECT ANSWER furan. There are
only five atoms in the ring: one oxygen and four carbons."
"When is the α 1→6 connection typically found in carbohydrates? - CORRECT ANSWER The α
1→6 bond is found in polysaccharides when branching occurs."
"Is the following an α 1→4 or β 1→4 connection? Briefly explain. - CORRECT ANSWER This is a
β 1→4 because the molecule on the left has the oxygen in the up, or beta, position." "What are the similarities and differences between amylose and amylopectin? Explain in at least
three complete sentences. - CORRECT ANSWER Similarities: Both of are homopolysaccharides
of glucose. They each have α1 → 4 connections between glucose. They each are part of starch. Differences: Amylopectin has branching with α1→6 linkages. Amylose does not. Amylopectin is typically larger than amylose."
"How is chitin different from cellulose? - CORRECT ANSWER Chitin has glucose with
derivatives attached. -NH-CO-CH3 is connected to each glucose."
"Where are α 1 → 6 bonds found in carbohydrates? - CORRECT ANSWER They are found where
glycogen and amylopectin branch."
