The pH of a solution is determined by

dielectric constant of the medium

relative concentration of acids and bases

dielectric constant of the medium

The reactions of molecules

are independent of the functional groups

are the reactions of the functional groups

are independent of the functional groups

Polyprotic acids such as H₃PO₄, can act as acid-base buffers

only in combination with polyprotic bases

if their concentration is kept low

at pH values around any of their pKa's

The elements oxygen, nitrogen, and carbon

can all form covalent bonds with other elements

contain protons and neutrons in their atomic nuclei

are common elements in the molecules that make up living organisms

Salt dissolves well in water as water molecules

share electrons with the ions to make polar covalent bonds

form hydrogen bonds with the positively and negatively charged ions

make nonpolar covalent bonds with the positively charged ions only

surround the ions because of their charge but do not form hydrogen bonds

share electrons with the ions to make polar covalent bonds

are rarely found in living systems

cause a decrease in pH when acids are added to them.

tend to maintain a relatively constant pH.

The lone pair electrons on oxygen in a H₂0 molecule

carry a partial positive charge

are not important for the properties of water

carry a partial negative charge

Which of the following statements about water is correct?

It is critical for many of the chemical processes found in living systems

Polar substances that can form hydrogen bonds will dissolve in it

Nonpolar substances like oils are not soluble in it

Which of the following statements about covalently bonded molecules is false?

The chemical bonds that hold the molecule together are relatively strong

Electrons are shared between the atoms that make up the molecule

Noncovalent bonds may also be present, especially if the molecule is large

Such molecules often result from the interaction of ionized atoms

The chemical bonds that hold the molecule together are relatively strong

The effectiveness or capacity of a buffer solution can be affected by

temperature of buffer components

molar concentration of the buffer components

concentration of the conjugate base to the weak acid

temperature of buffer components

Hydrogen bonds and hydrophilic interactions are types of

strong chemical bonds that link together separate molecules

weak chemical bonds that hold together the atoms within a molecule

strong chemical bonds that hold together the atoms within a molecule

weak chemical bonds that link together separate molecules

strong chemical bonds that link together separate molecules

The main difference between an acid and a base is that

bases are polar molecules and acids are not

acids are polar molecules and bases are not

bases donate hydrogen ions in water while acids accept hydrogen ions

acids donate hydrogen ions in water while bases accept hydrogen ions

Weak acids generally have pKa

10^-7 Mbeen seldom found in living systems

10^14 MpKa values greater than 2

10^-7 Mbeen seldom found in living systems

10^7 Mthat cannot be used to buffer

Which of the following character does not apply to water?

The covalent bonds in water are highly polarized

The water molecule is asymmetric

The water molecule readily forms hydrophobic interactions

The covalent bonds in water are highly polarized

All three atoms in the water molecule readily form hydrogen bonds

76 + Mcqs in Water pH and Macromolecules in Biochemistry Page 2 McqOptions

51.	The pH of a solution is determined by
A.	concentration of salt
B.	relative concentration of acids and bases
C.	dielectric constant of the medium
D.	environmental effect
Answer» C. dielectric constant of the medium

Discussion

52.	The reactions of molecules
A.	are the reactions of the functional groups
B.	are independent of the functional groups
C.	require an enzyme in all cases
D.	all of the above
Answer» B. are independent of the functional groups

Discussion

53.	Polyprotic acids such as H₃PO₄, can act as acid-base buffers
A.	only in combination with polyprotic bases
B.	if their concentration is kept low
C.	at pH values around neutrality
D.	at pH values around any of their pKa's
Answer» E.

Discussion

54.	Which of the following indicates that the pK of an acid is numerically equal to the pH of the solution when the molar concentration of the acid and its conjugate base are equal?
A.	Michaelis-Menten equation
B.	Haldanes equation
C.	Henderson-Hasselbalch equation
D.	Hardy-Windberg law
Answer» D. Hardy-Windberg law

Discussion

55.	Which of the following will easily dissolve in a polar solvent?
A.	gasoline (heptanes & octanes)
B.	methane
C.	argon
D.	sodium chloride
Answer» E.

Discussion

56.	In 3° structure of proteins, folding and shaping is done by ____________
A.	Hydrophobic interactions
B.	Polar interactions
C.	Hydrogen bonding
D.	None of the mentioned
Answer» B. Polar interactions

Discussion

57.	The elements oxygen, nitrogen, and carbon
A.	can all form covalent bonds with other elements
B.	contain protons and neutrons in their atomic nuclei
C.	are common elements in the molecules that make up living organisms
D.	All of the above
Answer» E.

Discussion

58.	Molecules in which the atoms are held together by __________ bonds have the strongest chemical linkages.
A.	noncovalent
B.	covalent
C.	ionic
D.	hydrogen
Answer» C. ionic

Discussion

59.	A Bronsted acid becomes __________ upon losing a proton.
A.	highly reactive
B.	its conjugate acid
C.	its conjugate base
D.	a hydronium ion
Answer» D. a hydronium ion

Discussion

60.	Salt dissolves well in water as water molecules
A.	form hydrogen bonds with the positively and negatively charged ions
B.	make nonpolar covalent bonds with the positively charged ions only
C.	surround the ions because of their charge but do not form hydrogen bonds
D.	share electrons with the ions to make polar covalent bonds
Answer» D. share electrons with the ions to make polar covalent bonds

Discussion

61.	Buffer solutions
A.	will always have a pH of 7
B.	are rarely found in living systems
C.	cause a decrease in pH when acids are added to them.
D.	tend to maintain a relatively constant pH.
Answer» E.

Discussion

62.	The lone pair electrons on oxygen in a H₂0 molecule
A.	carry a partial positive charge
B.	are not important for the properties of water
C.	carry a partial negative charge
D.	form covalent bonds in ice
Answer» D. form covalent bonds in ice

Discussion

63.	Which of the following statements about water is correct?
A.	It is critical for many of the chemical processes found in living systems
B.	Polar substances that can form hydrogen bonds will dissolve in it
C.	Nonpolar substances like oils are not soluble in it
D.	All of the above
Answer» E.

Discussion

64.	A biological polymer contains alanine, tyrosine, and lysine. Which of the following will be true about this molecule?
A.	DNA
B.	Strong base
C.	Phospholipid
D.	Protein
Answer» E.

Discussion

65.	Which of the following statements about covalently bonded molecules is false?
A.	Electrons are shared between the atoms that make up the molecule
B.	Noncovalent bonds may also be present, especially if the molecule is large
C.	Such molecules often result from the interaction of ionized atoms
D.	The chemical bonds that hold the molecule together are relatively strong
Answer» D. The chemical bonds that hold the molecule together are relatively strong

Discussion

66.	The strength of an acid depends on
A.	number of neutrons gain
B.	electronegativity
C.	number of double bonds
D.	number of protons released
Answer» C. number of double bonds

Discussion

67.	Which of the following organic groups are found in naturally occuring amino acids?
A.	Guanidinium ion
B.	Indole
C.	Imidazole
D.	All of these
Answer» E.

Discussion

68.	The effectiveness or capacity of a buffer solution can be affected by
A.	molar concentration of the buffer components
B.	concentration of the conjugate base to the weak acid
C.	both (a) and (b)
D.	temperature of buffer components
Answer» D. temperature of buffer components

Discussion

69.	H₂O and CH₄ are both examples of
A.	molecules
B.	ions
C.	acids
D.	none of these
Answer» B. ions

Discussion

70.	Hydrogen bonds and hydrophilic interactions are types of
A.	weak chemical bonds that hold together the atoms within a molecule
B.	strong chemical bonds that hold together the atoms within a molecule
C.	weak chemical bonds that link together separate molecules
D.	strong chemical bonds that link together separate molecules
Answer» D. strong chemical bonds that link together separate molecules

Discussion

71.	Who discovered and described the blood groups (ABO) classification?
A.	Theodor Kocher
B.	Karl Landsteiner
C.	Otto Warburg
D.	Karl Hooper
Answer» C. Otto Warburg

Discussion

72.	The main difference between an acid and a base is that
A.	bases are polar molecules and acids are not
B.	acids are polar molecules and bases are not
C.	bases donate hydrogen ions in water while acids accept hydrogen ions
D.	acids donate hydrogen ions in water while bases accept hydrogen ions
Answer» E.

Discussion

73.	Weak acids generally have pKa
A.	10^-14 Mvalues less than 1
B.	10^14 MpKa values greater than 2
C.	10^-7 Mbeen seldom found in living systems
D.	10^7 Mthat cannot be used to buffer
Answer» C. 10^-7 Mbeen seldom found in living systems

Discussion

74.	A solution with pH = 5 is __________ than a solution with pH = 7.
A.	2 times more basic
B.	10 times more basic
C.	10 times more acidic
D.	100 times more acidic
Answer» E.

Discussion

75.	The reason that fats contain more energy than simple sugars, is fats have many more
A.	carbon atoms
B.	hydrogen atoms
C.	covalent bonds
D.	hydrogen bonds
Answer» D. hydrogen bonds

Discussion

76.	Which of the following character does not apply to water?
A.	The water molecule is asymmetric
B.	The water molecule readily forms hydrophobic interactions
C.	The covalent bonds in water are highly polarized
D.	All three atoms in the water molecule readily form hydrogen bonds
Answer» C. The covalent bonds in water are highly polarized

Discussion

Explore topic-wise MCQs in Biochemistry.

The pH of a solution is determined by

The reactions of molecules

Polyprotic acids such as H₃PO₄, can act as acid-base buffers

Which of the following indicates that the pK of an acid is numerically equal to the pH of the solution when the molar concentration of the acid and its conjugate base are equal?

Which of the following will easily dissolve in a polar solvent?

In 3° structure of proteins, folding and shaping is done by ____________

The elements oxygen, nitrogen, and carbon

Molecules in which the atoms are held together by __________ bonds have the strongest chemical linkages.

A Bronsted acid becomes __________ upon losing a proton.

Salt dissolves well in water as water molecules

Buffer solutions

The lone pair electrons on oxygen in a H₂0 molecule

Which of the following statements about water is correct?

A biological polymer contains alanine, tyrosine, and lysine. Which of the following will be true about this molecule?

Which of the following statements about covalently bonded molecules is false?

The strength of an acid depends on

Which of the following organic groups are found in naturally occuring amino acids?

The effectiveness or capacity of a buffer solution can be affected by

H₂O and CH₄ are both examples of

Hydrogen bonds and hydrophilic interactions are types of

Who discovered and described the blood groups (ABO) classification?

The main difference between an acid and a base is that

Weak acids generally have pKa

A solution with pH = 5 is __________ than a solution with pH = 7.

The reason that fats contain more energy than simple sugars, is fats have many more

Which of the following character does not apply to water?