Mastering Biology 4

Which molecule is not a carbohydrate? Starch Cellulose Glycogen Lipid

A lipid is a hydrophobic polymer, not a carbohydrate.

Which polysaccharide contains a modified monosaccharide?

Peptidoglycan

Which statement is true of polymers? They are often made by a hydrolysis process. Their synthesis generally consumes water. They are always made by condensation reactions. They are always made of monomers. None of the above.

They are always made of monomers

True or false? Enzymes in the digestive tract catalyze hydrolysis reactions.

True

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

True

Which of these is a source of lactose? milk starch potatoes sugar cane sugar beets

milk

Which complex carbohydrate contains only a-1,4-glycosidic linkages? Amylopectin Cellulose Amylose Glycogen

Amylose

Which of the following is not attached to the central carbon atom in an amino acid? A carboxyl functional group An oxygen An amino functional group A side chain ("R group")

An oxygen

Which of the following statements about monosaccharide structure is true? All monosaccharides contain carbon, hydrogen, oxygen, and nitrogen atoms. Monosaccharides can be classified according to the spatial arrangement of their atoms. A six-carbon sugar is called a pentose. Aldoses and ketoses differ in the position of their hydroxyl groups.

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

Which monomers make up RNA? Polymers Amino acids Simple sugars Nucleotides

Nucleotides

Polymers that contain sugars ... (a) may store hereditary information. (b) may store energy. (c) may protect cells. Both (b) and (c). (a), (b), and (c).

a b and c

The organic molecule called DNA is an example of .... a protein. a polymer made of amino acids. a polymer made of nucleotides. a monomer. a polymer made of nucleotes.

a polymer made of nucleotides

Glycogen is _____. a transport protein that carries oxygen a polysaccharide found in plant cell walls a source of saturated fat a polysaccharide found in animals the form in which plants store sugars

a polysaccharide found in plant cell walls

Starch and cellulose _____. are used for energy storage in plants are structural components of the plant cell wall are polymers of glucose are cis-trans isomers of each other

are polymers of glucose

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 hexose as a disaccharide as a monosaccharide as a polysaccharide

disaccharide

The molecule shown in the accompanying figure is _____. a hexose fructose a pentose maltose

hexose

Humans can digest starch but not cellulose because _____. starch monomers are joined by covalent bonds and cellulose monomers are joined by ionic bonds humans have enzymes that can hydrolyze the α-glycosidic linkages of starch but not the β-glycosidic linkages of cellulose the monomer of starch is fructose, while the monomer of cellulose is glucose the monomer of starch is glucose, while the monomer of cellulose is galactose

humans have enzymes that can hydrolyze the α-glycosidic linkages of starch but not the β-glycosidic linkages of cellulose

What is the major structural difference between starch and glycogen? whether glucose is in the α or β form the amount of branching that occurs in the molecule the types of monosaccharide subunits in the molecules the type of glycosidic linkages in the molecule

the amount of branching that occurs in the molecule

Which of the following statements about the formation of polypeptides from amino acids is true? A bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid. A bond can form between any carbon and nitrogen atom in the two amino acids being joined. The reaction occurs through the addition of a water molecule to the amino acids. Polypeptides form by condensation or hydrolysis reactions.

A bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid.

Plant cell walls consist mainly of _____. chitin cellulose peptidoglycan chlorophyll None of the choices is correct.

cellulose

What does the term insoluble fiber refer to on food packages? amylopectin polypeptides starch cellulose

cellulose

Which of these is a polysaccharide? cellulose glucose lactose sucrose galactose

cellulose

_____ is the most abundant organic compound on Earth. Glycogen Lactose Glucose Starch Cellulose

cellulose

Sucrose is formed when glucose is joined to fructose by a(n) _____. phosphodiester linkage ester linkage ionic bond peptide linkage glycosidic linkage

glycosidic linkage

glucose + glucose —> _____ by _____. sucrose + water ... dehydration synthesis maltose + water ... dehydration synthesis cellulose + water ... hydrolysis lactose + water ... hydrolysis starch + water ... dehydration synthesis

maltose + water ... dehydration synthesis

A molecule with the chemical formula C6H12O6 is probably a _____. nucleic acid monosaccharide fatty acid polysaccharide

monosaccharide

Which polymers are composed of amino acids? Carbohydrates Proteins Nucleic acids Monomers

proteins

Select the statement that is incorrect. Complex sugars are carbohydrates. All carbohydrates have the general formula Cn(H2O)n. Simple sugars are carbohydrates. Simple sugars contain only carbon, oxygen, and hydrogen atoms.

All carbohydrates have the general formula Cn(h20)N

Which part of an amino acid is always acidic? Side chain ("R group") Amino functional group Carboxyl functional group None of the above

Carboxyl functional group

Which of the following complex carbohydrates is listed with its correct function? Amylose: main component of plant starch Cellulose: structural component of plant cell walls Starch: primary energy-storage molecule in animals Chitin: constituent of bacterial cell walls

Cellulose: structural component of plant cell walls