Bio chapter 5

Which of the following is true of cellulose?

It is a major structural component of plant cell walls.

If 14C-labeled uridine triphosphate is added to the growth medium of cells, what macromolecules will be labeled?

RNA

Which of the following statements about the 5' end of a polynucleotide strand of DNA is correct?

The 5' end has a phosphate group attached to the number 5 carbon of ribose.

The label on a container of margarine lists "hydrogenated vegetable oil" as the major ingredient. What is the result of adding hydrogens to vegetable oil?

The hydrogenated vegetable oil stays solid at room temperature.

Which of the following is true of both starch and cellulose?

They are both polymers of glucose.

Which of the following statements is true for the class of biological molecules known as lipids?

They are insoluble in water.

Why are human sex hormones considered to be lipids?

They are not soluble in water.

Which of the following statements concerning saturated fats is not true?

They have multiple double bonds in the carbon chains of their fatty acids.

Which of the following descriptions best fits the class of molecules known as nucleotides?

a nitrogenous base, a phosphate group, and a pentose sugar

Normal hemoglobin is a tetramer, consisting of two molecules of hemoglobin and two molecules of hemoglobin. In sickle-cell disease, as a result of a single amino acid change, the mutant hemoglobin tetramers associate with each other and assemble into large fibers. Based on this information alone, we can conclude that sickle-cell hemoglobin exhibits

altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered.

Polysaccharides, triacylglycerides, and proteins are similar in that they

are synthesized from subunits by dehydration reactions.

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 disaccharide

If cells are grown in a medium containing radioactive 32P-labeled phosphate, which of these molecules will be labeled?

both phospholipids and nucleic acids

If cells are grown in a medium containing radioactive 15N, which of these molecules will be labeled?

both proteins and nucleic acids

Which of the following categories includes all others in the list?

carbohydrate

A molecule with the chemical formula C6H12O6 is probably a

carbohydrate and monosaccharide only.

On food packages, to what does the term insoluble fiber refer?

cellulose

What is the term used for a protein molecule that assists in the proper folding of other proteins?

chaperonin

Which of the following polymers contain nitrogen?

chitin

All of the following contain amino acids except

cholesterol

The difference between the sugar in DNA and the sugar in RNA is that the sugar in DNA

contains one less oxygen atom.

Which of the following are nitrogenous bases of the pyrimidine type?

cytosine and uracil

What is the chemical reaction mechanism by which cells make polymers from monomers?

dehydration reactions

There are 20 different amino acids. What makes one amino acid different from another?

different side chains (R groups) attached to an carbon

What type of covalent bond between amino acid side chains (R groups) functions in maintaining a polypeptide's specific three-dimensional shape?

disulfide bond

Molecules with which functional groups may form polymers via dehydration reactions?

either hydroxyl or carboxyl groups

Which of these molecules is not formed by dehydration reactions?

fatty acids

One of the primary functions of RNA molecules is to

function in the synthesis of proteins.

Which of the following is not a polymer?

glucose

The enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are the form. Which of the following could amylase break down?

glycogen

Which of the following are nitrogenous bases of the purine type?

guanine and adenine

Humans can digest starch but not cellulose because

humans have enzymes that can hydrolyze the glycosidic linkages of starch but not the glycosidic linkages of cellulose.

Which type of interaction stabilizes the helix and the pleated sheet structures of proteins?

hydrogen bonds

What maintains the secondary structure of a protein?

hydrogen bonds between the amino group of one peptide bond and the carboxyl group of another peptide bond

All of the following are polysaccharides except

lactose

Which bonds are created during the formation of the primary structure of a protein?

peptide bonds

The structural level of a protein least affected by a disruption in hydrogen bonding is the

primary level

If cells are grown in a medium containing radioactive 35S, which of these molecules will be labeled?

proteins

What aspects of protein structure are stabilized or assisted by hydrogen bonds?

secondary, tertiary, and quaternary structures, but not primary structure

The bonding of two amino acid molecules to form a larger molecule requires

the release of a water molecule.

it results in a peptide bond

this is true when regarding this chemical reaction

A fat (or triacylglycerol) would be formed as a result of a dehydration reaction between

three molecules of 9 and one of 10

Which of the following is not a monomer/polymer pairing?

triglyceride/phospholipid bilayer

The tertiary structure of a protein is the

unique three-dimensional shape of the fully folded polypeptide.

Which level of protein structure do the helix and the pleated sheet represent?

unique three-dimensional shape of the fully folded polypeptide.

In animal metabolism, most of the monomers released by digestion of food macromolecules are metabolized to provide energy. Only a small portion of these monomers are used for synthesis of new macromolecules. The net result is that...

water is consumed by animal metabolism.

How many molecules of water are needed to completely hydrolyze a polymer that is 11 monomers long?

10

Which molecule is glycerol?

10

Which of the following combinations could be linked together to form a nucleotide?

11, 12, 13

Which of the following molecules is the pentose sugar found in RNA?

12

Which of the following molecules is a purine type of nitrogenous base?

13

Which of the following molecules contains a glycosidic linkage type of covalent bond?

15

Which of the following molecules has a functional group that frequently forms covalent bonds that maintain the tertiary structure of a protein?

2

Which of the following molecules act as building blocks (monomers) of polypeptides?

2, 7, 8

If a DNA sample were composed of 10% thymine, what would be the percentage of guanine?

40

Which molecule has both hydrophilic and hydrophobic properties and would be found in plasma membranes?

5

Which of the following pairs of base sequences could form a short stretch of a normal double helix of DNA?

5'-ATGC-3' with 5'-GCAT-3'

If one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other complementary strand would have the sequence

5'TGCAAT3'.

Which of the following molecules could be joined together by a peptide bond as a result of a dehydration reaction?

7, 8

Which molecule is a saturated fatty acid?

9

Upon chemical analysis, a particular polypeptide was found to contain 100 amino acids. How many peptide bonds are present in this protein?

99

Misfolding of polypeptides is a serious problem in cells. Which of the following diseases are associated with an accumulation of misfolded polypeptides?

Alzheimer's and Parkinson's only

Which of the following best summarizes the relationship between dehydration reactions and hydrolysis?

Dehydration reactions assemble polymers, and hydrolysis reactions break down polymers.