UMN BIOL 1009 Midterm 1 (Gibson) Exam
With Complete Solutions
A solution with a pH of 12 contains what concentration of hydroxyl ions [OH-]? -
ANSWER 0.01 moles/liter
-->
pH = - log [H+]
12 = - log [H+]
10^-14/10^-12
Molecules consisting only of carbon and hydrogen are known as - ANSWER
hydrocarbons
Organic chemistry is defined as - ANSWER the study of carbon compounds
What would be the sequence of the DNA molecule made using the following DNA
strand as a template?
5' AATTCGC 3' - ANSWER 5' GCGAATT 3'
Intermediate filaments - ANSWER have diameters that are larger than those
microfilaments but smaller than those microtubules
Which structure is NOT part of the endomembrane system?
1. nuclear envelope
2. golgi apparatus
3. mitochondria
4. plasma membrane - ANSWER mitochondria
All of the following play an important role in determining or maintaining the
structure of plant cells. Which of the following are distinct from the others in
their composition?
1. microtubules
2. microfilaments
3. plant cell walls.
4. intermediate filaments - ANSWER plant cell walls
Which of the following organelles does NOT have membrane as an important
part of its structure?
, 1. endoplasmic reticulum
2. golgi apparatus
3. mitochondria
4. ribosomes - ANSWER ribosomes
The sodium-potassium pump in animal cells requires cytoplasmic ATP to pump
ions across the plasma membrane. When the proteins of the pump are first
synthesized in the rough ER, what side of the ER membrane will the ATP binding
site be on? - ANSWER It will be on the cytoplasmic side of the ER.
The sucrose-H+ cotransporter is able to transport sucrose molecules up their
concentration gradient, into cells, because - ANSWER of the energy gained by
simultaneously transporting an H+ down its electrochemical gradient
Are most chemical reactions at equilibrium in living cells? - ANSWER no
At equilibrium, the free energy change is zero and no work can be done. So, a
cell where most reactions are at equilibrium would not be able to do enough
work and so would be dead
The synthesis of polymers from their constituent monomers occurs during -
ANSWER anabolism
Some bacteria are metabolically active in hot springs because - ANSWER their
enzymes have high optimal temperatures.
A series of enzymes catalyzes the series of reactions shown below. Product A
binds to the enzyme that converts X to Y at a position remote from its active site.
This binding decreases the activity of the enzyme. What is substance X? -
ANSWER substrate
The valence shell of an atom - ANSWER may correspond to the first, second,
third, fourth, fifth, sixth or seventh electron shells, depending on how many
electrons the atom has
L-methionine and D-methionine are examples of - ANSWER enantiomers
Polar molecules are often able to dissolve in water because - ANSWER The
partially charged regions of polar molecules are able to form hydrogen bonds
with water molecules.
Carbon atoms typically complete their valence shells by - ANSWER forming four
covalent bonds with other atoms
With Complete Solutions
A solution with a pH of 12 contains what concentration of hydroxyl ions [OH-]? -
ANSWER 0.01 moles/liter
-->
pH = - log [H+]
12 = - log [H+]
10^-14/10^-12
Molecules consisting only of carbon and hydrogen are known as - ANSWER
hydrocarbons
Organic chemistry is defined as - ANSWER the study of carbon compounds
What would be the sequence of the DNA molecule made using the following DNA
strand as a template?
5' AATTCGC 3' - ANSWER 5' GCGAATT 3'
Intermediate filaments - ANSWER have diameters that are larger than those
microfilaments but smaller than those microtubules
Which structure is NOT part of the endomembrane system?
1. nuclear envelope
2. golgi apparatus
3. mitochondria
4. plasma membrane - ANSWER mitochondria
All of the following play an important role in determining or maintaining the
structure of plant cells. Which of the following are distinct from the others in
their composition?
1. microtubules
2. microfilaments
3. plant cell walls.
4. intermediate filaments - ANSWER plant cell walls
Which of the following organelles does NOT have membrane as an important
part of its structure?
, 1. endoplasmic reticulum
2. golgi apparatus
3. mitochondria
4. ribosomes - ANSWER ribosomes
The sodium-potassium pump in animal cells requires cytoplasmic ATP to pump
ions across the plasma membrane. When the proteins of the pump are first
synthesized in the rough ER, what side of the ER membrane will the ATP binding
site be on? - ANSWER It will be on the cytoplasmic side of the ER.
The sucrose-H+ cotransporter is able to transport sucrose molecules up their
concentration gradient, into cells, because - ANSWER of the energy gained by
simultaneously transporting an H+ down its electrochemical gradient
Are most chemical reactions at equilibrium in living cells? - ANSWER no
At equilibrium, the free energy change is zero and no work can be done. So, a
cell where most reactions are at equilibrium would not be able to do enough
work and so would be dead
The synthesis of polymers from their constituent monomers occurs during -
ANSWER anabolism
Some bacteria are metabolically active in hot springs because - ANSWER their
enzymes have high optimal temperatures.
A series of enzymes catalyzes the series of reactions shown below. Product A
binds to the enzyme that converts X to Y at a position remote from its active site.
This binding decreases the activity of the enzyme. What is substance X? -
ANSWER substrate
The valence shell of an atom - ANSWER may correspond to the first, second,
third, fourth, fifth, sixth or seventh electron shells, depending on how many
electrons the atom has
L-methionine and D-methionine are examples of - ANSWER enantiomers
Polar molecules are often able to dissolve in water because - ANSWER The
partially charged regions of polar molecules are able to form hydrogen bonds
with water molecules.
Carbon atoms typically complete their valence shells by - ANSWER forming four
covalent bonds with other atoms
