Exam 5: An Introduction to Carbohydrates

Glucose (C6H12O6) has a single carbonyl group (-C=O) in its linear form. Based on the number of oxygen atoms in glucose, how many hydroxyl groups (-OH) would you expect glucose to have?

Starch and cellulose ________.

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 α-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 NAG, and 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?

Why do plants require sunlight?

If two molecules of the general type shown in the accompanying figure were linked together, carbon-1 of one molecule to carbon-4 of the other, the single molecule that would result would be ________.

You isolate an organic molecule that contains C, H, O, N, and S. This molecule ________.

Which polysaccharide is an important component in the structure of many animals and fungi?

Cell walls are used by many different organisms for protection from their environment and structural support. These cell walls must obviously be insoluble in water; otherwise, they would dissolve the first time an organism got wet. Which of the following carbohydrates would you expect to be most soluble in water?

Which of the following is NOT a polymer?

A molecule with the chemical formula C6H12O6 is probably a ________.

A glycosidic linkage is analogous to which of the following in proteins?

Which of the following best explains why "carbs" (carbohydrates) are advertised by manufacturers of candy bars and sports drinks as a "quick energy boost"?

Bacteria, insects, and plants use carbohydrates to build structures. Which of the following is TRUE of structural carbohydrates?

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?

If you were going to develop a new antibiotic against bacteria, you would probably need to become an expert on which of these carbohydrates?

A primary function of carbohydrates attached to the glycoproteins and glycolipids of animal cell membranes is to ________.

Which of the following would you expect to have the most free energy per gram? The most free energy per gram would be found in a molecule with ________.

Enzymes that readily break starch apart cannot hydrolyze the glycosidic linkages found in cellulose. Why is this logical?

Which of these best reflects the following relationship: monosaccharide versus polysaccharide?

Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified?