BIO 110 EXAM 2 STUDY GUIDE QUESTIONS AND ANSWERS | COMPLETE
INTRODUCTORY BIOLOGY EXAM 2 REVIEW 2026/2027
What is the overall reaction for photosynthesis? (both chemical, and in common terms) - ANS ✔✔6CO2
+ 6H2O + sunlight --> C6H12O6 + 6O2
sunlight energy and carbon dioxide and water combine to produce sugar and oxygen (the reverse is
cellular respiration)
What happens in light reactions and the Calvin Cycle (inputs and outputs). - ANS ✔✔The inputs for the
light reactions are H2O and light and the byproduct is oxygen (O2), ATP, and NADPH. The input for the
Calvin Cycle are CO2 are sugar.
Where is water split? - ANS ✔✔water is split during PSII
What happens to the components of water through the rest of the process? - ANS ✔✔H+ are pumped to
the thylakoid lumen and electrons pass to PSI
Where are ATP and NADPH produced - ANS ✔✔In the Light Dependent reactions of Photosynthesis: this
is in the thylakoid membrane. More specifically, they are created through Photosystems I and II. PSII
makes ATP while PSI makes NADPH.
How is sunlight captured / what do pigments do? - ANS ✔✔Sunlight is captured by pigments through
absorption. They absorb different wavelengths of light.
antenna complex - ANS ✔✔harnesses light energy in PSI and directs it to the reaction center
reaction center - ANS ✔✔organized association of proteins holding a special pair of chlorophyl molecules
and light energy splits water into O2 & H+
resonance energy - ANS ✔✔mechanism by which antenna complex chlorophylls transfer energy toward
reaction centers
Track the energy and electron through PSII and PSI (Be able to draw the Z-scheme) - ANS ✔✔
Where does light energy become chemical energy? - ANS ✔✔inner thylakoid space
Understand how cyclic photophosphorylation works and what is it used for - ANS ✔✔Cyclic
Phosphorylation is a route of electron flow during the light reactions of photosynthesis that involves only
one photosystem and that produces ATP but not NADPH or O2. This process is utilized when when there
is no NADP+ available to act as the final electron acceptor. This occurs mostly in bacteria.
How is the H+ gradient created and what is it used for? - ANS ✔✔The H+ gradient is created when
electrons are transported down a chain and it is uses proton motive force*************
, What would happen if you change the pH of the chloroplast - ANS ✔✔If you change the pH of the
chloroplasts, the proteins present in them will have the propensity to denature and therefore become
void.
How are the products of the light reactions used in the Calvin Cycle to make sugars? - ANS ✔✔The Calvin
cycle uses the chemical energy of ATP and NADPH to reduce CO2 to sugar.
Explain what is meant by "the overall process of photosynthesis is to reduce carbon dioxide" - ANS
✔✔Reduction is reducing oxygen and adding an electron (H+). This is how carbon dioxide is altered to
turn into sugar.
What does RUBISCO do and why is it such a critical enzyme? - ANS ✔✔it is the most abundant enzyme
on Earth
- takes CO2 from the air and adds it to a solid molecule (carbon fixation)
Know the general properties of DNA structure (should be review from exam I) - ANS ✔✔DNA is
composed of a sugar group, a phosphate group, and a nitrogenous base (A,T,C,G). The nitrogenous bases
are bonded together via hydrogen bonds.
semi-conservative DNA replication - ANS ✔✔after replication, the 2 new DNA copies contain one old
strand and one new strand
conservative DNA replication - ANS ✔✔the original double helix of DNA does not change at all. It is as if
the DNA is placed on a copy machine and and exact duplicate is made. DNA from another parent
appears in only one of the two daughter cells
dispersive DNA replication - ANS ✔✔DNA breaks into fragments, resulting in a haphazard, ~50/50 mix of
old and new strands (model not accepted)
How was this was discovered (Meselson and Stahl) - ANS ✔✔In semiconservative replication, the double
stranded DNA helix is replicated. Then, each of the two new double-stranded DNA helixes consisted of
one strand from the original helix and one newly synthesized. Meselson and Stahl decided the best way
to test this was to tag the parent DNA, changing the atoms in the parent DNA molecule. Since nitrogen is
found in the nitrogenous bases of each nucleotide, they decided to use an isotope of nitrogen to
distinguish between parent and newly-copied DNA. They facilitated replication in a controlled
environment and found evidence that supported semiconservative replication by looking at the tagged
regions in the original and complimentary DNA strands.
Understand how DNA is replicated and the factors involved - ANS ✔✔DNA replications occurs in the
nucleus and uses a template mechanism that relies on base-pairing rules. You begin with original DNA
that has a double strand of enzymes. Next, the enzymes separate otherwise known as the S phase in cell
division. Then, new bases are added to each single strand. Finally, the double strands are formed.
(parents are templates)
What is an origin of replication? - ANS ✔✔A short stretch of DNA with a particular set of bases where
replication starts.
In what direction does replication occur? - ANS ✔✔5' to 3'
INTRODUCTORY BIOLOGY EXAM 2 REVIEW 2026/2027
What is the overall reaction for photosynthesis? (both chemical, and in common terms) - ANS ✔✔6CO2
+ 6H2O + sunlight --> C6H12O6 + 6O2
sunlight energy and carbon dioxide and water combine to produce sugar and oxygen (the reverse is
cellular respiration)
What happens in light reactions and the Calvin Cycle (inputs and outputs). - ANS ✔✔The inputs for the
light reactions are H2O and light and the byproduct is oxygen (O2), ATP, and NADPH. The input for the
Calvin Cycle are CO2 are sugar.
Where is water split? - ANS ✔✔water is split during PSII
What happens to the components of water through the rest of the process? - ANS ✔✔H+ are pumped to
the thylakoid lumen and electrons pass to PSI
Where are ATP and NADPH produced - ANS ✔✔In the Light Dependent reactions of Photosynthesis: this
is in the thylakoid membrane. More specifically, they are created through Photosystems I and II. PSII
makes ATP while PSI makes NADPH.
How is sunlight captured / what do pigments do? - ANS ✔✔Sunlight is captured by pigments through
absorption. They absorb different wavelengths of light.
antenna complex - ANS ✔✔harnesses light energy in PSI and directs it to the reaction center
reaction center - ANS ✔✔organized association of proteins holding a special pair of chlorophyl molecules
and light energy splits water into O2 & H+
resonance energy - ANS ✔✔mechanism by which antenna complex chlorophylls transfer energy toward
reaction centers
Track the energy and electron through PSII and PSI (Be able to draw the Z-scheme) - ANS ✔✔
Where does light energy become chemical energy? - ANS ✔✔inner thylakoid space
Understand how cyclic photophosphorylation works and what is it used for - ANS ✔✔Cyclic
Phosphorylation is a route of electron flow during the light reactions of photosynthesis that involves only
one photosystem and that produces ATP but not NADPH or O2. This process is utilized when when there
is no NADP+ available to act as the final electron acceptor. This occurs mostly in bacteria.
How is the H+ gradient created and what is it used for? - ANS ✔✔The H+ gradient is created when
electrons are transported down a chain and it is uses proton motive force*************
, What would happen if you change the pH of the chloroplast - ANS ✔✔If you change the pH of the
chloroplasts, the proteins present in them will have the propensity to denature and therefore become
void.
How are the products of the light reactions used in the Calvin Cycle to make sugars? - ANS ✔✔The Calvin
cycle uses the chemical energy of ATP and NADPH to reduce CO2 to sugar.
Explain what is meant by "the overall process of photosynthesis is to reduce carbon dioxide" - ANS
✔✔Reduction is reducing oxygen and adding an electron (H+). This is how carbon dioxide is altered to
turn into sugar.
What does RUBISCO do and why is it such a critical enzyme? - ANS ✔✔it is the most abundant enzyme
on Earth
- takes CO2 from the air and adds it to a solid molecule (carbon fixation)
Know the general properties of DNA structure (should be review from exam I) - ANS ✔✔DNA is
composed of a sugar group, a phosphate group, and a nitrogenous base (A,T,C,G). The nitrogenous bases
are bonded together via hydrogen bonds.
semi-conservative DNA replication - ANS ✔✔after replication, the 2 new DNA copies contain one old
strand and one new strand
conservative DNA replication - ANS ✔✔the original double helix of DNA does not change at all. It is as if
the DNA is placed on a copy machine and and exact duplicate is made. DNA from another parent
appears in only one of the two daughter cells
dispersive DNA replication - ANS ✔✔DNA breaks into fragments, resulting in a haphazard, ~50/50 mix of
old and new strands (model not accepted)
How was this was discovered (Meselson and Stahl) - ANS ✔✔In semiconservative replication, the double
stranded DNA helix is replicated. Then, each of the two new double-stranded DNA helixes consisted of
one strand from the original helix and one newly synthesized. Meselson and Stahl decided the best way
to test this was to tag the parent DNA, changing the atoms in the parent DNA molecule. Since nitrogen is
found in the nitrogenous bases of each nucleotide, they decided to use an isotope of nitrogen to
distinguish between parent and newly-copied DNA. They facilitated replication in a controlled
environment and found evidence that supported semiconservative replication by looking at the tagged
regions in the original and complimentary DNA strands.
Understand how DNA is replicated and the factors involved - ANS ✔✔DNA replications occurs in the
nucleus and uses a template mechanism that relies on base-pairing rules. You begin with original DNA
that has a double strand of enzymes. Next, the enzymes separate otherwise known as the S phase in cell
division. Then, new bases are added to each single strand. Finally, the double strands are formed.
(parents are templates)
What is an origin of replication? - ANS ✔✔A short stretch of DNA with a particular set of bases where
replication starts.
In what direction does replication occur? - ANS ✔✔5' to 3'
