NAS Exam #2 - Questions With Verified Solutions
why is chemical energy needed by cells? Correct Ans - to maintain
homeostasis
Define cell respiration Correct Ans - the mechanism for harvesting
energy from fuel molecules; the oxidation of glucose to produce ATP
what is the function of the reduced coenzymes? Correct Ans - They
are used to transfer energy to another compound
Describe the function of oxidation-reduction reactions in the synthesis of
ATP. Correct Ans - The reaction that transports energy to reduced
coenzymes for synthesis of ATP
How are hydrogen atoms involved the redox reactions? Correct Ans -
When redox reactions take place they usually involve the loss of hydrogen
atoms.
What happens to the energy stored within the newly formed reduced
coenzyme? Why is this referred to as phosphorylation? Correct Ans -
Phosphorylation is the addition of a phosphate group to a molecule.
Name the four steps in cell respiration Correct Ans - 1. Glycolysis,
2. Formation of acetyl coenzyme A, 3. Krebs cycle, 4. Electron transport
chain
Why is glycolysis "anaerobic" while the other three pathways are "aerobic."
Correct Ans - Because oxygen is not required to generate ATP during
glycolysis.
Where does glycolysis occur? Correct Ans - in the cytosol
Two ATP molecules are used to split a glucose molecule. ATP is actually
gained through glycolysis, however. How much ATP is produced by this
process and what is the net gain? Correct Ans - 4 ATP gross, 2 net
, How many reduced coenzyme molecules are produced by glycolysis?
Correct Ans - 2
Two molecules are produced by glycolysis. Identify them. Correct Ans -
Pyruvic acid & NADH + H+
Describe the conditions that result in lactic acid production Correct
Ans - anaerobic, not enough oxygen
Where within the cell will further oxidation of pyruvic acid molecules occur
Correct Ans - In the matrix of the mitochondria
Describe the two steps that result in the formation of acetyl Co-enzyme A.
Correct Ans - 1. A molecule of CO2 is removed from the pyruvic acid
through decarboxylation. Pyruvic acid is oxidized. 2. The acetyl group binds
with Co-enzyme A to form acetyl CoA.
Each glucose molecule results in the production of 6 CO2 molecules as a
waste gas. How many CO2 molecules are produced in glycolysis and how
many in the Krebs cycle? Correct Ans - 2 - Glycolysis, 4 - Krebs cycle
How many ATP are produced during the Krebs cycle? Correct Ans -
2
What happens to the remainder of the energy harvested through the Krebs
cycle? Correct Ans - It is transferred to reduced coenzymes that
will go through the ETC and be converted to ATP.
What is the primary function of the Krebs cycle? Correct Ans - The
production of reduced co-enzymes.
What is the function of the electron transport chain? Correct Ans -
The synthesis of ATP
What is a by-production of the ETC reaction Correct Ans - Water as
the H- is released and combined w/ oxygen
Define Chemiosmosis Correct Ans - the process by which ATP is
produced as hydrogen ions move down their concentration gradient.
why is chemical energy needed by cells? Correct Ans - to maintain
homeostasis
Define cell respiration Correct Ans - the mechanism for harvesting
energy from fuel molecules; the oxidation of glucose to produce ATP
what is the function of the reduced coenzymes? Correct Ans - They
are used to transfer energy to another compound
Describe the function of oxidation-reduction reactions in the synthesis of
ATP. Correct Ans - The reaction that transports energy to reduced
coenzymes for synthesis of ATP
How are hydrogen atoms involved the redox reactions? Correct Ans -
When redox reactions take place they usually involve the loss of hydrogen
atoms.
What happens to the energy stored within the newly formed reduced
coenzyme? Why is this referred to as phosphorylation? Correct Ans -
Phosphorylation is the addition of a phosphate group to a molecule.
Name the four steps in cell respiration Correct Ans - 1. Glycolysis,
2. Formation of acetyl coenzyme A, 3. Krebs cycle, 4. Electron transport
chain
Why is glycolysis "anaerobic" while the other three pathways are "aerobic."
Correct Ans - Because oxygen is not required to generate ATP during
glycolysis.
Where does glycolysis occur? Correct Ans - in the cytosol
Two ATP molecules are used to split a glucose molecule. ATP is actually
gained through glycolysis, however. How much ATP is produced by this
process and what is the net gain? Correct Ans - 4 ATP gross, 2 net
, How many reduced coenzyme molecules are produced by glycolysis?
Correct Ans - 2
Two molecules are produced by glycolysis. Identify them. Correct Ans -
Pyruvic acid & NADH + H+
Describe the conditions that result in lactic acid production Correct
Ans - anaerobic, not enough oxygen
Where within the cell will further oxidation of pyruvic acid molecules occur
Correct Ans - In the matrix of the mitochondria
Describe the two steps that result in the formation of acetyl Co-enzyme A.
Correct Ans - 1. A molecule of CO2 is removed from the pyruvic acid
through decarboxylation. Pyruvic acid is oxidized. 2. The acetyl group binds
with Co-enzyme A to form acetyl CoA.
Each glucose molecule results in the production of 6 CO2 molecules as a
waste gas. How many CO2 molecules are produced in glycolysis and how
many in the Krebs cycle? Correct Ans - 2 - Glycolysis, 4 - Krebs cycle
How many ATP are produced during the Krebs cycle? Correct Ans -
2
What happens to the remainder of the energy harvested through the Krebs
cycle? Correct Ans - It is transferred to reduced coenzymes that
will go through the ETC and be converted to ATP.
What is the primary function of the Krebs cycle? Correct Ans - The
production of reduced co-enzymes.
What is the function of the electron transport chain? Correct Ans -
The synthesis of ATP
What is a by-production of the ETC reaction Correct Ans - Water as
the H- is released and combined w/ oxygen
Define Chemiosmosis Correct Ans - the process by which ATP is
produced as hydrogen ions move down their concentration gradient.
