NAS Exam #2 UPDATED ACTUAL Exam
Questions and CORRECT Answers
why is chemical energy needed by cells? - CORRECT ANSWER - to maintain
homeostasis
Define cell respiration - CORRECT ANSWER - the mechanism for harvesting energy
from fuel molecules; the oxidation of glucose to produce ATP
what is the function of the reduced coenzymes? - CORRECT ANSWER - They are used to
transfer energy to another compound
Describe the function of oxidation-reduction reactions in the synthesis of ATP. - CORRECT
ANSWER - The reaction that transports energy to reduced coenzymes for synthesis of ATP
How are hydrogen atoms involved the redox reactions? - CORRECT ANSWER - 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 ANSWER - Phosphorylation is the addition
of a phosphate group to a molecule.
Name the four steps in cell respiration - CORRECT ANSWER - 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
ANSWER - Because oxygen is not required to generate ATP during glycolysis.
Where does glycolysis occur? - CORRECT ANSWER - 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 ANSWER - 4 ATP gross, 2 net
How many reduced coenzyme molecules are produced by glycolysis? - CORRECT
ANSWER -2
Two molecules are produced by glycolysis. Identify them. - CORRECT ANSWER -
Pyruvic acid & NADH + H+
Describe the conditions that result in lactic acid production - CORRECT ANSWER -
anaerobic, not enough oxygen
Where within the cell will further oxidation of pyruvic acid molecules occur - CORRECT
ANSWER - In the matrix of the mitochondria
Describe the two steps that result in the formation of acetyl Co-enzyme A. - CORRECT
ANSWER - 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
ANSWER - 2 - Glycolysis, 4 - Krebs cycle
How many ATP are produced during the Krebs cycle? - CORRECT ANSWER -2
What happens to the remainder of the energy harvested through the Krebs cycle? - CORRECT
ANSWER - 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 ANSWER - The production
of reduced co-enzymes.
What is the function of the electron transport chain? - CORRECT ANSWER - The
synthesis of ATP
What is a by-production of the ETC reaction - CORRECT ANSWER - Water as the H- is
released and combined w/ oxygen
Define Chemiosmosis - CORRECT ANSWER - the process by which ATP is produced as
hydrogen ions move down their concentration gradient.
What protein enzyme is involved in chemiosmosis? - CORRECT ANSWER - ATP
Synthase
Why is ATP construction an example of an anabolic reaction? - CORRECT ANSWER -
simpler molecules are built up into more complex molecules to form ATP.
Why is breaking down larger and more complex food molecules an example of catabolism -
CORRECT ANSWER - Catabolism is breaking down larger, more complex molecules in
order to harvest energy from them.
Identify the two different types of reactions involved in energy transfer. - CORRECT
ANSWER - 1. Oxidation & reductions reactions - produce reduced coenzymes which
receive energy from high energy fuel molecules. 2. ATP generation reactions - produce ATP
which stores the energy harvested from the reduced coenzymes.
Describe an oxidation reaction and explain an example involving this energy transfer process -
CORRECT ANSWER - Oxidation liberates energy in the form of H atoms from high
energy fuel molecules. An example is the conversion of lactic acid into pyruvic acid.
Questions and CORRECT Answers
why is chemical energy needed by cells? - CORRECT ANSWER - to maintain
homeostasis
Define cell respiration - CORRECT ANSWER - the mechanism for harvesting energy
from fuel molecules; the oxidation of glucose to produce ATP
what is the function of the reduced coenzymes? - CORRECT ANSWER - They are used to
transfer energy to another compound
Describe the function of oxidation-reduction reactions in the synthesis of ATP. - CORRECT
ANSWER - The reaction that transports energy to reduced coenzymes for synthesis of ATP
How are hydrogen atoms involved the redox reactions? - CORRECT ANSWER - 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 ANSWER - Phosphorylation is the addition
of a phosphate group to a molecule.
Name the four steps in cell respiration - CORRECT ANSWER - 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
ANSWER - Because oxygen is not required to generate ATP during glycolysis.
Where does glycolysis occur? - CORRECT ANSWER - 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 ANSWER - 4 ATP gross, 2 net
How many reduced coenzyme molecules are produced by glycolysis? - CORRECT
ANSWER -2
Two molecules are produced by glycolysis. Identify them. - CORRECT ANSWER -
Pyruvic acid & NADH + H+
Describe the conditions that result in lactic acid production - CORRECT ANSWER -
anaerobic, not enough oxygen
Where within the cell will further oxidation of pyruvic acid molecules occur - CORRECT
ANSWER - In the matrix of the mitochondria
Describe the two steps that result in the formation of acetyl Co-enzyme A. - CORRECT
ANSWER - 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
ANSWER - 2 - Glycolysis, 4 - Krebs cycle
How many ATP are produced during the Krebs cycle? - CORRECT ANSWER -2
What happens to the remainder of the energy harvested through the Krebs cycle? - CORRECT
ANSWER - 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 ANSWER - The production
of reduced co-enzymes.
What is the function of the electron transport chain? - CORRECT ANSWER - The
synthesis of ATP
What is a by-production of the ETC reaction - CORRECT ANSWER - Water as the H- is
released and combined w/ oxygen
Define Chemiosmosis - CORRECT ANSWER - the process by which ATP is produced as
hydrogen ions move down their concentration gradient.
What protein enzyme is involved in chemiosmosis? - CORRECT ANSWER - ATP
Synthase
Why is ATP construction an example of an anabolic reaction? - CORRECT ANSWER -
simpler molecules are built up into more complex molecules to form ATP.
Why is breaking down larger and more complex food molecules an example of catabolism -
CORRECT ANSWER - Catabolism is breaking down larger, more complex molecules in
order to harvest energy from them.
Identify the two different types of reactions involved in energy transfer. - CORRECT
ANSWER - 1. Oxidation & reductions reactions - produce reduced coenzymes which
receive energy from high energy fuel molecules. 2. ATP generation reactions - produce ATP
which stores the energy harvested from the reduced coenzymes.
Describe an oxidation reaction and explain an example involving this energy transfer process -
CORRECT ANSWER - Oxidation liberates energy in the form of H atoms from high
energy fuel molecules. An example is the conversion of lactic acid into pyruvic acid.
