bio concept check chapter 5

what are the four main classes of large biological molecules? which class does not consist of polymers?

the four main classes are proteins, carbohydrates, lipids, and nucleic acids. lipids are not polymers

how many molecules of water are needed to completely hydrolyze a polymer that is ten monomers long?

nine, with one water molecule required to hydrolyze each connection between adjacent monomers

if you eat a piece of fish, what reactions must occur for the amino acid monomers in the protein of the fish to be converted to new proteins in your body?

the amino acids in the fish protein must be released in hydrolysis reactions and incorporated into other proteins in dehydration reactions

write the formula for a monosaccharide that has three carbons


a dehydration reaction joins two glucose molecules to form maltose. the formula for glucose is C6H12O6. what is the formula for maltose?


after a cow is given antibiotics to treat an infection, a vet gives the animal a drink of 'gut culture' containing various prokaryotes. why is this necessary?

the antibiotic treatment is likely to have killed the cellulose-digesting prokaryotes in the cow's gut. The absence of these prokaryotes would hamper the cow's ability to obtain energy from food and could lead to weight loss and possibly death. Thus, prok

compare the structure of a fat with that of a phospholipid

both have a glycerol molecule attached to fatty acids

why are human sex hormones considered lipids?

human sex hormones are steroids, a type of compound that is hydrophobic and thus classified as a lipid

suppose a membrane surrounded an oil droplet, as it does in the cells of plant seeds and in some animal cells. describe and explain the form it might take.

the oil droplet membrane could consist of a single layer of phospholipids rather than a bilayer, because an arrangement in which the hydrophobic tails of the membrane phospholipids were in contact with the hydrocarbon regions of the oil molecules would be

what parts of a polypeptide participate in the bonds that hold together secondary structure? tertiary structure?

secondary structure involves hydrogen bonds between atoms of the polypeptide backbone. tertiary structure involves interactions between atoms in the side chains of the amino acid subunits

thus far in the chapter, the greek letters a and b have been used to specify at least three different pairs of structures. name and briefly describe them.

the two ring forms of glucose are called a and b, depending on how the glycosidic bond dictates the position of a hydroxyl group. proteins have a helices and b pleated sheets, two types of repeating structures found in polypeptides due to interactions bet

which of the following categories includes all others in the list?
a. monosaccharide
b. polysaccharide
c. starch
d. carbohydrate

d. carbohydrate

the enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are in the a form. which of the following could amylase break down?
a. glycogen, starch, and amylopectin
b. glycogen and cellulose
c. cellulose and chitin
d. st

a. glycogen, starch, and amylopectin

which of the following is true of unsaturated fats?
a. they are more common in animals than in plants
b. they have double bonds in the carbon chains of their
fatty acids
c. they generally solidify at room temperature
d. they contain more hydrogen than do

b. they have double bonds in the carbon chains of their fatty acids

the structural level of a protein least affected by a disruption in hydrogen bonding is the
a. primary level
b. secondary level
c. tertiary level
d. quaternary level

a. primary level

enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. what would happen to DNA molecules treated with these enzymes?
a. the two strands of the double helix would separate
b. the phosphodiester linkages o

b. the phosphodiester linkages of the polynucleotide backbone would be broken