Biology Ch. 1-3 Concepts and Connections

In proteins, elements of secondary structure combine to form a(n) A) domain B) motif C) alpha helix D) beta sheet E) chaperone

b

The functional group - NH2 is a(n) A) carboxyl group B) amino group C) hydroxyl group D) phosphate group

b

There are several levels of protein structure, the most complex of which is A) primary B) secondary C) tertiary D) quaternary

d

Which of the following is not a characteristic of prokaryotes? A) DNA B) cell membrane C) cell wall D) endoplasmic reticulum

d

Which of the following is not part of the scientific process? A) making predictions B) asking questions C) using creative insight D) proving theories are true

d

Which of the following nitrogenous bases is found in DNA but is not found in RNA? A) adenine B) guanine C) cytosine D) thymine E) uracil

d

Which of the following statements concerning scientific hypotheses is false? A) Their consequences can be tested by different investigators. B) They can be used to make predictions. C) They are not always correct. D) They are the same as theories. E) They are constructed based on observations.

d

Covalent bonds result from A) the sharing of equal numbers of electrons by two atoms B) the exchange of equal numbers of electrons by two atoms C) the combination of two atoms of the same valence D) sharing of unequal numbers of electrons by two atoms

a

Glycogen, starch, and cellulose are all polymers of glucose. A) True B) False

a

Hydrogen bonds form when hydrogen in one polar molecule is attracted to the electronegative portion of another molecule. A) True B) False

a

Of the following elements, which is the least common in living organisms? A) sodium B) oxygen C) hydrogen D) nitrogen E) carbon

a

Polymerization reactions in which polysaccharides are synthesized from monosaccharides or proteins are synthesized from amino acids: A) result in the formation of water. B) are hydrolysis reactions. C) release energy. D) result in the formation of covalent bonds between monomers called peptide bonds. E) all of the above.

a

Hydrolysis of one molecule of a triglyceride to glycerol and fatty acids yields two molecules of water. A) True B) False

b

The general term for a large molecule made up of many similar subunits is A) polymer B) functional group C) peptide D) helix E) pectin

a

The sequence of amino acids in a polypeptide is called the A) primary structure B) secondary structure C) tertiary structure D) quaternary structure

a

The strongest and most stable chemical bonds are A) covalent bonds B) ionic bonds C) hydrogen bonds D) those where free electrons are available to form other bonds

a

Using general principles to analyze specific cases is called A) deductive reasoning B) inductive reasoning C) natural selection D) artificial selection

a

What type of macromolecule carries out catalysis in biological systems? A) proteins called enzymes B) carbohydrates called starches C) lipids called steroids D) nucleic acids called DNA E) carbohydrates called sugars

a

Which of the following is not a lipid? A) chitin B) terpenes C) steroids D) prostaglandins E) unsaturated fat

a

Which of the following is not a property of life? A) molding or adapting to one's environment B) regulating materials that enter or leave the system C) responding to stimuli D) maintaining a relatively constant internal condition E) reproducing, passing hereditary material to the next generation

a

Why is cellulose so difficult for most animals to digest? A) they don't have the proper enzyme to break the bonds between subunits B) cellulose is made up of chitin, which is indigestible C) the bonds holding cellulose subunits together are extremely strong, stronger than in any other macromolecule D) there are many hydrogen bonds holding the subunits together

a

A protein with quaternary structure contains four domains. A) True B) False

b

All of the following are true of protein denaturation except that it A) is a shape change B) is always irreversible C) may be caused by a pH change D) could result from a temperature change

b

Amino acids and proteins are ionized at typical biological pH such that both the amino group and the carboxyl group gain hydrogen ions to become -NH3+ and -COOH, respectively. A) True B) False

b

Animals store glucose in the form of A) amylose B) glycogen C) glycerol D) guanine E) cellulose

b

Atomic number is equal to the number of _____ in the nucleus of the atom. A) electrons B) protons C) neutrons D) positrons

b

Evolution and natural selection are the same thing. A) True B) False

b

What happens during a hydrolysis reaction? A) protein coils into its secondary structure B) the bond between two subunits of a macromolecule is broken C) saturated fats become unsaturated D) a bond is formed between two subunits of a macromolecule E) water breaks ionic bonds

b

Which of the following statements about water is false? A) water molecules are polar B) it takes very little heat to change the temperature of water C) all living organisms contain water D) ice is less dense than liquid water E) none; all these statements are true

b

During oxidation, molecules A) disintegrate B) gain neutrons C) lose electrons D) lose carbon E) are converted to oxygen atoms

c

Isotopes differ in A) their number of protons B) their number of electrons C) their number of neutrons D) their ions E) their atomic numbers

c

Of the following biological levels of organization, which represents the smallest or lowest level? A) organs B) populations C) cells D) organisms E) tissues

c

The globular shape of a protein is called the A) primary structure B) secondary structure C) tertiary structure D) quaternary structure

c

Triacylglycerol contains fatty acids and A) glucose B) glycogen C) glycerol D) guanine E) an amino group

c

Which chemical bond is the strongest? A) ionic bond B) single covalent bond C) double covalent bond D) hydrogen bond

c

Which of the following pH values represents the greatest concentration of H+ ions? A) 4 B) 10 C) 2 D) 7 E) 12

c

Which of the following pH values represents the strongest acid? A) 4 B) 10 C) 2 D) 7 E) 12

c

Which of the pHs listed below represents the strongest base? A) 7 B) 10 C) 13 D) 15

c (The highest pH number on the scale is the strongest base, but the scale ends with pH 14)

A hydrocarbon is said to be saturated if: A) one end of the molecule is hydrophilic while the other end is hydrophobic. B) it has one or more double bonds between carbon atoms. C) it contains more than one functional group. D) each internal carbon atom is covalently bonded to two hydrogen atoms. E) its functional groups include at least one aromatic ring.

d

An element having 8 protons, 8 neutrons, and 8 electrons would weigh _____ daltons. A) 8 B) 32 C) 24 D) 16

d

Assuming they all had the same number of carbon atoms, which of the following has the most C-H bonds? A) an unsaturated fat B) a polyunsaturated fat C) a polysaccharide D) a saturated fat

d

Bases A) donate H+ ions to solutions B) accept H+ ions from solutions C) accept OH- from solutions D) both b and c

d

Glucose is a A) protein B) disaccharide C) nucleic acid D) monosaccharide E) starch

d

Hydrophilic substances are ________________, whereas hydrophobic substances are _____________. A) water-loving; water-fearing B) polar; non-polar C) soluble in water; soluble in lipid D) a-c are all are correct E) a-c are all are incorrect

d

Hydrophobic interactions are exhibited by A) ions B) hydration shells C) polar molecules D) nonpolar molecules E) all of the above

d

If you remove all of the functional groups from an organic molecule so that it has only carbon and hydrogen atoms, the molecule becomes a _____ molecule. A) carbohydrate B) carbonyl C) carboxyl D) hydrocarbon

d

In the formation of a macromolecule, what type of bond would join two amino acid subunits? A) ionic bond B) phosphodiester bond C) hydrogen bond D) peptide bond

d

In the study of science A) deductive reasoning may be used, but inductive reasoning is preferred B) inductive reasoning may be used, but deductive reasoning is preferred C) only inductive reasoning is used D) either deductive reasoning, inductive reasoning, or both may be used

d

Molecules that have the same chemical formula but have different molecular structures are called A) isotopes B) ions C) structural isotopes D) isomers E) both a and c

d

In a DNA molecule, what holds together nitrogenous bases from the two polymer chains? A) phosphodiester bonds B) ionic bonds C) covalent bonds D) peptide bonds E) hydrogen bonds

e

At what level(s) of protein structure would you expect to find disulfide bridges? A) primary B) secondary C) tertiary D) quaternary E) only in b and c

e

Dehydration and hydrolysis reactions involve removing or adding _______________ to macromolecule subunits. A) C and O B) CH and NH2 C) C and H D) COOH and H E) OH and H

e

In ionic bonds, A) electrons are shared unequally between atoms B) electrons are shared equally between atoms C) neutrons are transferred between atoms D) protons are shared equally between atoms E) electrons are transferred between atoms

e

The chemical properties of an atom are primarily determined by the number of A) neutrons it has in its nucleus B) isotopes it forms C) protons it has in its nucleus D) energy levels it has E) electrons it has in its outermost energy level

e

Which of the following is a characteristic of proteins? A) Some may enhance the rate of specific chemical reactions. B) They may form either long, thin fibrous molecules or compact, rounded globular molecules. C) They store genetic information for cellular metabolism. D) They form through hydrolysis reactions. E) a and b

e

Which of the following is not a disaccharide? A) sucrose B) maltose C) lactose D) amylose E) all of the above are disaccarides

e