lipid (A lipid is a hydrophobic polymer, not a carbohydrate.)
question
Which of the following statements about monosaccharide structure is true?
answer
Monosaccharides can be classified according to the spatial arrangement of their atoms.
question
True or false? Peptidoglycan is a polysaccharide found only in bacteria.
answer
true
question
Which complex carbohydrate contains only a-1,4-glycosidic linkages?
answer
Amylose (Amylose is formed from a-1,4-glycosidic linkages of glucose.)
question
Which of the following complex carbohydrates is listed with its correct function?
answer
Cellulose: structural component of plant cell walls (Cellulose is indeed the main structural component of plant cells walls.)
question
Which polysaccharide contains a modified monosaccharide?
answer
Peptidoglycan (The N-acetylglucosamine and N-acetylmuramic acid units that make up peptidoglycan are composed of modified glucose monomers.)
question
You isolate an organic molecule that contains C, H, O, N, and S. This molecule _____.
answer
could be a glycoprotein (can't rule out glycoprotein because both sugars and proteins have C, H and O.)
question
What is the difference between an aldose sugar and a ketose sugar?
answer
the position of the carbonyl group
question
Which of the following linkages would you expect to find at a branch point in glycogen or amylopectin?
answer
Ξ±-1,6-glycosidic linkage
question
What is the major structural difference between starch and glycogen?
answer
the amount of branching that occurs in the molecule
question
Which of these best reflects the following relationship: monosaccharide versus polysaccharide?
answer
glucose versus glycogen
question
Which of the following molecules would you expect to have the most free energy per gram?
answer
one with carbon and hydrogen atoms only
question
Bacteria, insects, and plants use carbohydrates to build structures. Which of the following is true of structural carbohydrates?
answer
Structural carbohydrates are long strands of monomers; the strands are chemically linked together to form a network
question
Use the following paragraph to answer the corresponding question.
Masatomo Kawakubo et al. reported in Science in August 2004 that the human stomach contains a natural, carbohydrate-based antibiotic that probably protects a large portion of the population from various diseases caused by the bacterium Helicobacter pylori. This bacterium has been linked to peptic ulcers, gastritis, and stomach cancer. This naturally occurring antibiotic is described by Kawakubo as having a terminal 1,4-linked N-acetylglucosamine (NAG), and it acts by inhibiting the biosynthesis of a major component of the cell wall in H. pylori. [Source: M. Kawakubo et al., Science 305 (2004): 1003.]
Refer to the paragraph about Kawakubo's group. Kawakubo's group created a glycoprotein with a terminal NAG (i.e., a protein with NAG attached to its end). Their hypothesis is that the terminal NAGand not the protein component-is responsible for the damage to the cell wall in H. pylori. What would be the most appropriate control for testing this hypothesis?
answer
Grow H. pylori in a test tube with glycoprotein that has its terminal NAG removed. (This question includes concepts from Chapter 1. If the instructor has not yet discussed experimental controls, this question would make an excellent introduction to the subject.)
question
Which statement best summarizes a key difference in the structure of polysaccharides that function in energy storage versus structural support (in that order)?
answer
Built from -glycosidic linkages; form straight chains that bond with adjacent chains.
question
Glucose-6-phosphate dehydrogenase deficiency (G6PD) is inherited as a recessive allele of an X-linked gene in humans. A woman whose father suffered from G6PD marries a normal man. (a) What proportion of their sons is expected to be G6PD? (b) If the husband was not normal but was G6PD deficient, would you change your answer in part (a)?
answer
(a) 1/2; (b) no
question
The _____ functional group can always be found in a carbohydrate molecule.
answer
carbonyl
question
Which of the following classes of macromolecules always contains a carbohydrate portion?
answer
nucleic acids
question
A monosaccharide that has the chemical formula C5 H10 O5 would be characterized as a _____.
answer
pentose
question
A glycosidic linkage is a covalent bond that links two _____.
answer
monosaccharides
question
Both carbohydrates and fats are used as fuel in cells, but fats store twice as much energy per gram as carbohydrates. Which statement best explains why?
answer
Fats have more and bonds with high free energy, and fewer bonds with low free energy. (Fats store more chemical energy per gram than do carbohydrates.)
question
Carbohydrates that function as structural molecules withstand pulling and pushing forces well. Which structural feature best explains why?
answer
Structural polysaccharides exist as sets of long, parallel strands that are linked to one another. (These structural features result in tough fibers.)
question
Where are carbohydrates found in relationship to the cell?
answer
They are found both inside and outside the cell.
question
Which of the following chemical bonds have the lowest free energy?
answer
C-O bonds
question
Different types of glycosidic linkage cause glucose polymers to form a helix (e.g., in glycogen) versus a straight chain (e.g., in cellulose). Which statement best explains why?
answer
The geometry of the -1,4-glycosidic linkage results in a flipped orientation of adjacent glucose monomers; the -1,4-glycosidic linkage does not. (The flipped orientation results in a linear polymer, whereas the unflipped orientation results in a helix.)
Haven't found what you need?
Search for quizzes and test answers now
Quizzes.studymoose.com uses cookies. By continuing you agree to our cookie policy
