BIOS100 Chapter 5

Which complex carbohydrate contains only a-1,4-glycosidic linkages?

Amylose

The _____ functional group can always be found in a carbohydrate molecule.

hydroxyl

What is the difference between an aldose sugar and a ketose sugar?

the position of the carbonyl group

Which of the following do starch and cellulose have in common?

the size of their monosaccharide subunits

Which of the following complex carbohydrates is listed with its correct function?

Cellulose: structural component of plant cell walls

Which of the following polysaccharides composes the cell wall of fungi?

Chitin - is a structural polysaccharide that forms the cell wall of fungi and is also found in the exoskeleton of insects.

Dairy cattle were unknown in Thai culture until recently, and 97 percent of Thai people are lactose intolerant as adults. Which explanation for such widespread lactose intolerance is most likely correct?

Evolutionarily, producing an enzyme to break down a sugar that will never be encountered is wasteful.

Which feature is shared by all monosaccharides?

In their linear forms, they all contain a carbonyl and several hydroxyl functional groups.

Which molecule is not a carbohydrate?

Lipid

Which of the following statements about monosaccharide structure is true?

Monosaccharides can be classified according to the spatial arrangement of their atoms.

Which polysaccharide contains a modified monosaccharide?

Peptidoglycan

Which statement best summarizes a key difference in the structure of polysaccharides that function in energy storage versus those used in structural support?

Polysaccharides that function in energy storage are built from α glycosidic linkages, whereas polysaccharides used in structural support form straight chains that bond with adjacent chains

How do the α and β forms of glucose differ?

Their ring structures differ in the location of a hydroxyl group.

Which of the following structural features is common to cellulose, chitin, and peptidoglycan?

They can all form bonds between polymer chains that create parallel strands.

True or false? Peptidoglycan is a polysaccharide found only in bacteria.

True

Cellulose is _____.

a major structural component of plant cell walls

Glycogen is _____.

a polysaccharide found in animals

Cells of which organisms lack cell walls?

animals

Starch and cellulose _____.

are polymers of glucose

Which of these is a polysaccharide?

cellulose

The bond that joins two monosaccharides into a disaccharide is a(n) _____.

glycosidic bond

What type of bond is formed between two sugars in a disaccharide?

glycosidic linkage

glucose + glucose —> _____ by _____.

maltose + water ... dehydration synthesis

A sugar that has the chemical formula C5H10O5 would be characterized as a(n) _____.

pentose

Which of the following polysaccharides contains peptide bonds?

peptidoglycan -is a structural polysaccharide found in bacterial cell walls. The sugars are modified with amino acids that can form peptide bonds to covalently link adjacent strands.

What is the major structural difference between starch and glycogen?

the amount of branching that occurs in the molecule

Which of the following linkages would you expect to find at a branch point in glycogen or amylopectin?

α-1,6-glycosidic linkage