Intro to Molecular Cell Biology Test Bank
Chapter 2
Chemical reactions in living systems occur in an ____________________ environment, within a
narrow range of temperatures.
(a) optimal
(b) organic
(c) extracellular
(d) aqueous - ANS(d) aqueous
True or false: The chemistry of life is carried out and coordinated primarily by the action of small
molecules. - ANSFalse. Although small molecules are important in many processes, the
chemical reactions in living systems are regulated by the coordinated action of large polymeric
molecules.
True or false: Carbon-based compounds make up the vast majority of molecules found in cells. -
ANSTrue
True or false: The chemical reactions in living systems are loosely regulated allowing for a wide
range of products and more rapid evolution. - ANStrue
Which subatomic particles contribute to the atomic mass for any given element?
(a) protons
(b) protons and neutrons
(c) protons and electrons
(d) neutrons - ANS(b) protons and neutrons
Which subatomic particles can vary between isotopes of the same element, without changing
the observed chemical properties?
(a) electrons
(b) protons and neutrons
(c) neutrons
(d) neutrons and electrons - ANS(c) neutrons
What is the correct atomic number and atomic weight respectively for an atom of carbon? -
ANS6, 12
Carbon 14 is an unstable isotope of carbon that decays very slowly. Compared to the common,
stable carbon 12 isotope, carbon 14 has two additional _______________________.
(a) electrons
(b) neutrons
, (c) protons
(d) ions - ANS(b) neutrons
If the isotope 32 S has 16 protons and 16 neutrons, how many protons, neutrons, and electrons
will the isotope 35 have, respectively?
(a) 16, 20, 15
(b) 16, 19, 15
(c) 16,19, 16
(d) 16, 19, 17 - ANS(c) 16, 19, 16
If 0.5 mole of glucose weighs 90 g, what is the molecular mass of glucose? - ANS180 daltons. A
mole of a substance has a mass equivalent to its molecular weight expressed in grams.
What is the concentration, in grams per liter (g/L), of a 0.25 M solution of glucose? - ANS45g/L
How many molecules are there in 1 mole of glucose? - ANS6X10^23
Which of the following elements is least abundant in living organisms?
(a) sulfer
(b) carbon
(c) oxygen
(d) nitrogen - ANS(a) sulfer
How many moles and atoms are there in 120 grams of sulfur? - ANS3.75 and 2.25x10^24
The first task you are assigned in your summary lab job is to prepare a concentrated NaOH
stock solution. The molecular weight of NaOH is 40. How many grams of solid NaOH will you
need to weigh out to obtain a 500 mL solution that has a concentration of 10 M?
(a) 800 g
(b) 200 g
(c) 400 g
(d) 160 g - ANS(b) 200 g
You have a concentrated stock solution of 10 M NaOh and want to use it to produce a 150mL
solution of 3 NaOH. What volume of water and stock solutions will you measure out to make this
new solution?
(a) 135 mL of water, 15 mL of NaOH stock
(b) 115 mL of water, 35 mL of NaOH stock
(c) 100 mL of water, 50 mL of NaOh stock
(d) 105 mL of water, 45 mL of NaOH stock - ANS(d) 105 mL of water, 45 mL of NaOH stock
True or false: Electron shells fill discrete regions around the nucleus of the atom and limit the
number of electrons that can occupy a specific orbit. - ANStrue
Chapter 2
Chemical reactions in living systems occur in an ____________________ environment, within a
narrow range of temperatures.
(a) optimal
(b) organic
(c) extracellular
(d) aqueous - ANS(d) aqueous
True or false: The chemistry of life is carried out and coordinated primarily by the action of small
molecules. - ANSFalse. Although small molecules are important in many processes, the
chemical reactions in living systems are regulated by the coordinated action of large polymeric
molecules.
True or false: Carbon-based compounds make up the vast majority of molecules found in cells. -
ANSTrue
True or false: The chemical reactions in living systems are loosely regulated allowing for a wide
range of products and more rapid evolution. - ANStrue
Which subatomic particles contribute to the atomic mass for any given element?
(a) protons
(b) protons and neutrons
(c) protons and electrons
(d) neutrons - ANS(b) protons and neutrons
Which subatomic particles can vary between isotopes of the same element, without changing
the observed chemical properties?
(a) electrons
(b) protons and neutrons
(c) neutrons
(d) neutrons and electrons - ANS(c) neutrons
What is the correct atomic number and atomic weight respectively for an atom of carbon? -
ANS6, 12
Carbon 14 is an unstable isotope of carbon that decays very slowly. Compared to the common,
stable carbon 12 isotope, carbon 14 has two additional _______________________.
(a) electrons
(b) neutrons
, (c) protons
(d) ions - ANS(b) neutrons
If the isotope 32 S has 16 protons and 16 neutrons, how many protons, neutrons, and electrons
will the isotope 35 have, respectively?
(a) 16, 20, 15
(b) 16, 19, 15
(c) 16,19, 16
(d) 16, 19, 17 - ANS(c) 16, 19, 16
If 0.5 mole of glucose weighs 90 g, what is the molecular mass of glucose? - ANS180 daltons. A
mole of a substance has a mass equivalent to its molecular weight expressed in grams.
What is the concentration, in grams per liter (g/L), of a 0.25 M solution of glucose? - ANS45g/L
How many molecules are there in 1 mole of glucose? - ANS6X10^23
Which of the following elements is least abundant in living organisms?
(a) sulfer
(b) carbon
(c) oxygen
(d) nitrogen - ANS(a) sulfer
How many moles and atoms are there in 120 grams of sulfur? - ANS3.75 and 2.25x10^24
The first task you are assigned in your summary lab job is to prepare a concentrated NaOH
stock solution. The molecular weight of NaOH is 40. How many grams of solid NaOH will you
need to weigh out to obtain a 500 mL solution that has a concentration of 10 M?
(a) 800 g
(b) 200 g
(c) 400 g
(d) 160 g - ANS(b) 200 g
You have a concentrated stock solution of 10 M NaOh and want to use it to produce a 150mL
solution of 3 NaOH. What volume of water and stock solutions will you measure out to make this
new solution?
(a) 135 mL of water, 15 mL of NaOH stock
(b) 115 mL of water, 35 mL of NaOH stock
(c) 100 mL of water, 50 mL of NaOh stock
(d) 105 mL of water, 45 mL of NaOH stock - ANS(d) 105 mL of water, 45 mL of NaOH stock
True or false: Electron shells fill discrete regions around the nucleus of the atom and limit the
number of electrons that can occupy a specific orbit. - ANStrue
