TAMU BIOL 111 FLETCHER FINAL EXAM LATEST 2026 UPDATED
QUESTIONS AND VERIFIED 100% SOLUTIONS (2026/2027) |A+
GRADED |GUARANTEED PASS
explain what and enzyme is and how it affects chemical reactions - Answers -a catalytic protein
that speeds up reactions by lowering the required activation energy/energy barriers, they a very
specific, and bind with reactant molecules
compare and contrast competitive and non-competitive inhibition of enzyme activities -
Answers --Competitive: similar shape to substrate, binds to active site, competes with substrate
for active site
-Non-competitive: bind to enzyme a different location, changes the function, causes a slower
reaction rate
compare and contrast an enzyme active site and allosteric site - Answers --active site: where the
substrate binds to the enzyme
-allosteric site: where the noncompetitive inhibitor binds to the enzyme
explain how feedback inhibition is used to regulate biochemical pathways - Answers -the end
product inhibits and upstream step, which in turn shuts down the reaction
explain how this inhibition benefits the cell - Answers -regulates the cell reactions by causing
them to end when needed, and thus help control the cells metabolism
1|Page
,discuss the importance of electrons in the transfer of energy in living systems - Answers -
electrons are transferred incrementally via electron carriers, to provide energy to produce ATP
explain how ATP is used by cells as an energy source - Answers -ATP allows for the transport of
energy within the cell, and the ATP is harvested through the phosphorylation of ADP
define oxidation and reduction - Answers -Oxidation is the loss of an electron
Reduction is gain of an electron
OIL RIG Oxidation is Loss Reduction is Gain
explain the role of NAD+ in cellular respiration with respect to glycolysis - Answers -the NAD+
carries the electrons to this first phase of cellular respiration, 2 NAD+ are input
describe the flow of metabolites and electrons during glycolysis (inputs and outputs, precise
cellular locations) - Answers -All occurs in the cytoplasm
Inputs:
-1 glucose (energy investment phase)
-2 NAD+ (energy payoff phase)
-2 ATP (energy investment phase)
-4 ADP (energy payoff phase)
4 Pi (energy payoff phase)
Outputs:
-2 pyruvate (energy payoff phase)
2|Page
,-2 H2O (energy payoff phase)
-2 NADH (energy payoff phase)
-4 ATP (energy payoff phase)
-2 ADP (energy investment phase)
-2 Pi (energy investment phase)
-2 H+ (energy payoff phase)
explain the importance of glycolysis - Answers -it is the first metabolic pathway of glucose
metabolism, produces the inputs needed for the next step of cellular respiration
explain how a circular pathway, like the citric acid cycle, fundamentally differs from a linear
biochemical pathway, like glycolysis - Answers -a circular pathway has multiple entry and exit
points, where as a linear pathway takes one trip trough and thats that
describe the flow of electrons and metabolites during the citric acid cycle (inputs and outputs,
precise cellular locations) - Answers -Occurs in the matrix of the mitochondria
Inputs:
-All 2x
-acetyl CoA
-oxaloacetate (already in cycle)
-3 NAD+
-1 FAD
Outputs:
-All 2x
3|Page
, -3 NADH
-1 FADH2
-H2O
-1 ATP/GTP (cell type)
-2 CO2
Series of 8 steps that utilize oxygen to transfer electrons to next pathway
describe how pyruvate is prepared for entry into the citric acid cycle - Answers -3 step process:
1) Carboxyl group is removed (1st C removed) and releases a molecule of CO2 into its
surroundings
2) Hydroxyethyl group is oxidized to an acetyl group , electrons are picked up by NAD+, forms
NADH- sent to electron transport chain
3) Enzyme bound acetyl group is transferred to CoA, which produces acetyl CoA
describe the flow of electrons and metabolites during oxidative phosphorylation (inputs and
outputs, precise cellular locations) - Answers -Occurs inside the cristae, the inner mitochondrial
membrane
Inputs:
-electrons from NADH and FADH2
-O2 as terminal electron acceptor
Outputs:
-reduced O2 to H2O
-Proton gradient across the inner mitochondrial membrane that is used to drive ATP synthesis
4|Page
QUESTIONS AND VERIFIED 100% SOLUTIONS (2026/2027) |A+
GRADED |GUARANTEED PASS
explain what and enzyme is and how it affects chemical reactions - Answers -a catalytic protein
that speeds up reactions by lowering the required activation energy/energy barriers, they a very
specific, and bind with reactant molecules
compare and contrast competitive and non-competitive inhibition of enzyme activities -
Answers --Competitive: similar shape to substrate, binds to active site, competes with substrate
for active site
-Non-competitive: bind to enzyme a different location, changes the function, causes a slower
reaction rate
compare and contrast an enzyme active site and allosteric site - Answers --active site: where the
substrate binds to the enzyme
-allosteric site: where the noncompetitive inhibitor binds to the enzyme
explain how feedback inhibition is used to regulate biochemical pathways - Answers -the end
product inhibits and upstream step, which in turn shuts down the reaction
explain how this inhibition benefits the cell - Answers -regulates the cell reactions by causing
them to end when needed, and thus help control the cells metabolism
1|Page
,discuss the importance of electrons in the transfer of energy in living systems - Answers -
electrons are transferred incrementally via electron carriers, to provide energy to produce ATP
explain how ATP is used by cells as an energy source - Answers -ATP allows for the transport of
energy within the cell, and the ATP is harvested through the phosphorylation of ADP
define oxidation and reduction - Answers -Oxidation is the loss of an electron
Reduction is gain of an electron
OIL RIG Oxidation is Loss Reduction is Gain
explain the role of NAD+ in cellular respiration with respect to glycolysis - Answers -the NAD+
carries the electrons to this first phase of cellular respiration, 2 NAD+ are input
describe the flow of metabolites and electrons during glycolysis (inputs and outputs, precise
cellular locations) - Answers -All occurs in the cytoplasm
Inputs:
-1 glucose (energy investment phase)
-2 NAD+ (energy payoff phase)
-2 ATP (energy investment phase)
-4 ADP (energy payoff phase)
4 Pi (energy payoff phase)
Outputs:
-2 pyruvate (energy payoff phase)
2|Page
,-2 H2O (energy payoff phase)
-2 NADH (energy payoff phase)
-4 ATP (energy payoff phase)
-2 ADP (energy investment phase)
-2 Pi (energy investment phase)
-2 H+ (energy payoff phase)
explain the importance of glycolysis - Answers -it is the first metabolic pathway of glucose
metabolism, produces the inputs needed for the next step of cellular respiration
explain how a circular pathway, like the citric acid cycle, fundamentally differs from a linear
biochemical pathway, like glycolysis - Answers -a circular pathway has multiple entry and exit
points, where as a linear pathway takes one trip trough and thats that
describe the flow of electrons and metabolites during the citric acid cycle (inputs and outputs,
precise cellular locations) - Answers -Occurs in the matrix of the mitochondria
Inputs:
-All 2x
-acetyl CoA
-oxaloacetate (already in cycle)
-3 NAD+
-1 FAD
Outputs:
-All 2x
3|Page
, -3 NADH
-1 FADH2
-H2O
-1 ATP/GTP (cell type)
-2 CO2
Series of 8 steps that utilize oxygen to transfer electrons to next pathway
describe how pyruvate is prepared for entry into the citric acid cycle - Answers -3 step process:
1) Carboxyl group is removed (1st C removed) and releases a molecule of CO2 into its
surroundings
2) Hydroxyethyl group is oxidized to an acetyl group , electrons are picked up by NAD+, forms
NADH- sent to electron transport chain
3) Enzyme bound acetyl group is transferred to CoA, which produces acetyl CoA
describe the flow of electrons and metabolites during oxidative phosphorylation (inputs and
outputs, precise cellular locations) - Answers -Occurs inside the cristae, the inner mitochondrial
membrane
Inputs:
-electrons from NADH and FADH2
-O2 as terminal electron acceptor
Outputs:
-reduced O2 to H2O
-Proton gradient across the inner mitochondrial membrane that is used to drive ATP synthesis
4|Page
