NAS Exam 2 Questions And Answers
why do cells need chemical energy? - ANSWER to maintain homeostasis
Define cellular respiration - ANSWER the process by which energy is extracted from fuel
molecules; the oxidation of glucose to generate ATP
what are the functions of the reduced coenzymes? - ANSWER They are used to pass
energy on to another compound
Explain the role of oxidation-reduction reactions in the production of ATP. - ANSWER
The reaction that transfers energy to reduced coenzymes for production of ATP
How are hydrogen atoms participate in the redox reactions? - ANSWER When redox
reactions occur they normally involve the loss of hydrogen atoms.
What happens to the energy stored within the newly formed reduced coenzyme? Why is
this considered phosphorylation? - ANSWER Phosphorylation is the adding of a
phosphate to a molecule.
Name the four stages of cellular respiration - 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." - ANSWER
Because oxygen is not required to generate ATP during glycolosis.
Where does glycolosis take place? - ANSWER in the cytosol
Two ATP molecules are used to split a glucose molecule. ATP is actually gained through
,glycolosis, however. How much ATP is produced by this process and what is the net
gain? - ANSWER 4 ATP gross, 2 net
How many reduced coenzyme molecules are produced by glycolysis? - ANSWER 2
Two molecules are produced by glycolysis. Identify them. - ANSWER Pyruvic acid &
NADH + H+
Describe the conditions that result in lactic acid production - ANSWER anaerobic, not
enough oxygen
Where within the cell will further oxidation of pyruvic acid molecules occur - ANSWER In
the matrix of the mitochondria
Describe the two steps in the formation of acetyl Co-enzyme A. - ANS 1. One molecule of
CO2 is decarboxylated off the pyruvic acid. Pyruvic acid becomes oxidised. 2. The
acetyl group combines with Co-enzyme A to form acetyl CoA.
Each glucose molecule results in 6 CO2 molecules as a waste gas. How many are
produced in glycolysis and how many in the Krebs cycle? - ANS 2 - Glycolysis, 4 - Krebs
cycle
How many ATP are produced during the Krebs cycle? - ANS 2
What happens to the rest of the energy produced by the Krebs cycle? - ANSWER This is
stored in the form of reduced coenzymes, which would undergo ETC to get it converted
into ATP.
What is the most important outcome of Krebs cycle? - ANSWER Synthesis of reduced
co-enzymes.
, What is the task for electron transport chain? - ANSWER Synthesis of ATP
What is a by-production of the ETC reaction ANSWER Water as the H- is released and
combined w/ oxygen
Define Chemiosmosis ANSWER the process by which ATP is produced as hydrogen ions
move down their concentration gradient.
What protein enzyme is involved in chemiosmosis? ANSWER ATP Synthase
Why does the synthesis of ATP represent an example of an anabolic reaction? ANSWER
ATP is a more complex molecule synthesized from simpler molecules.
Why does catabolism include the breakdown of larger and more complex food
molecules? ANSWER Catabolism is the breakdown of larger, more complex molecules
for the express purpose of harvesting energy from them.
Name two different types of reactions involved in energy transfer. - ANSWER 1.
Oxidation & reductions reactions-produces 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 - 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.
Describe a reduction reaction and explain an example involving this energy transfer
process. - ANSWER Reduction transfers the liberated energy to a molecule
Phosphorylation- ANSWER adding a phosphate group to ADP to form ATP
why do cells need chemical energy? - ANSWER to maintain homeostasis
Define cellular respiration - ANSWER the process by which energy is extracted from fuel
molecules; the oxidation of glucose to generate ATP
what are the functions of the reduced coenzymes? - ANSWER They are used to pass
energy on to another compound
Explain the role of oxidation-reduction reactions in the production of ATP. - ANSWER
The reaction that transfers energy to reduced coenzymes for production of ATP
How are hydrogen atoms participate in the redox reactions? - ANSWER When redox
reactions occur they normally involve the loss of hydrogen atoms.
What happens to the energy stored within the newly formed reduced coenzyme? Why is
this considered phosphorylation? - ANSWER Phosphorylation is the adding of a
phosphate to a molecule.
Name the four stages of cellular respiration - 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." - ANSWER
Because oxygen is not required to generate ATP during glycolosis.
Where does glycolosis take place? - ANSWER in the cytosol
Two ATP molecules are used to split a glucose molecule. ATP is actually gained through
,glycolosis, however. How much ATP is produced by this process and what is the net
gain? - ANSWER 4 ATP gross, 2 net
How many reduced coenzyme molecules are produced by glycolysis? - ANSWER 2
Two molecules are produced by glycolysis. Identify them. - ANSWER Pyruvic acid &
NADH + H+
Describe the conditions that result in lactic acid production - ANSWER anaerobic, not
enough oxygen
Where within the cell will further oxidation of pyruvic acid molecules occur - ANSWER In
the matrix of the mitochondria
Describe the two steps in the formation of acetyl Co-enzyme A. - ANS 1. One molecule of
CO2 is decarboxylated off the pyruvic acid. Pyruvic acid becomes oxidised. 2. The
acetyl group combines with Co-enzyme A to form acetyl CoA.
Each glucose molecule results in 6 CO2 molecules as a waste gas. How many are
produced in glycolysis and how many in the Krebs cycle? - ANS 2 - Glycolysis, 4 - Krebs
cycle
How many ATP are produced during the Krebs cycle? - ANS 2
What happens to the rest of the energy produced by the Krebs cycle? - ANSWER This is
stored in the form of reduced coenzymes, which would undergo ETC to get it converted
into ATP.
What is the most important outcome of Krebs cycle? - ANSWER Synthesis of reduced
co-enzymes.
, What is the task for electron transport chain? - ANSWER Synthesis of ATP
What is a by-production of the ETC reaction ANSWER Water as the H- is released and
combined w/ oxygen
Define Chemiosmosis ANSWER the process by which ATP is produced as hydrogen ions
move down their concentration gradient.
What protein enzyme is involved in chemiosmosis? ANSWER ATP Synthase
Why does the synthesis of ATP represent an example of an anabolic reaction? ANSWER
ATP is a more complex molecule synthesized from simpler molecules.
Why does catabolism include the breakdown of larger and more complex food
molecules? ANSWER Catabolism is the breakdown of larger, more complex molecules
for the express purpose of harvesting energy from them.
Name two different types of reactions involved in energy transfer. - ANSWER 1.
Oxidation & reductions reactions-produces 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 - 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.
Describe a reduction reaction and explain an example involving this energy transfer
process. - ANSWER Reduction transfers the liberated energy to a molecule
Phosphorylation- ANSWER adding a phosphate group to ADP to form ATP
