NAS Exam #2 2024/2025 Exam
Questions Marking Scheme New Update
| A+ Rated
why is chemical energy needed by cells? - 🧠ANSWER ✔✔to maintain
homeostasis
Define cell respiration - 🧠ANSWER ✔✔the mechanism for harvesting
energy from fuel molecules; the oxidation of glucose to produce ATP
what is the function of the reduced coenzymes? - 🧠ANSWER ✔✔They are
used to transfer energy to another compound
Describe the function of oxidation-reduction reactions in the synthesis of
ATP. - 🧠ANSWER ✔✔The reaction that transports energy to reduced
coenzymes for synthesis of ATP
How are hydrogen atoms involved the redox reactions? - 🧠ANSWER
✔✔When redox reactions take place they usually involve the loss of
hydrogen atoms.
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STATEMENT. ALL RIGHTS RESERVED
,What happens to the energy stored within the newly formed reduced
coenzyme? Why is this referred to as phosphorylation? - 🧠ANSWER
✔✔Phosphorylation is the addition of a phosphate group to a molecule.
Name the four steps in cell 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
glycolysis.
Where does glycolysis occur? - 🧠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? - 🧠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+
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STATEMENT. ALL RIGHTS RESERVED
, 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 that result in the formation of acetyl Co-enzyme A. -
🧠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? - 🧠ANSWER ✔✔2 - Glycolysis, 4 - Krebs cycle
How many ATP are produced during the Krebs cycle? - 🧠ANSWER ✔✔2
What happens to the remainder of the energy harvested through the Krebs
cycle? - 🧠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? - 🧠ANSWER ✔✔The
production of reduced co-enzymes.
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
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STATEMENT. ALL RIGHTS RESERVED
Questions Marking Scheme New Update
| A+ Rated
why is chemical energy needed by cells? - 🧠ANSWER ✔✔to maintain
homeostasis
Define cell respiration - 🧠ANSWER ✔✔the mechanism for harvesting
energy from fuel molecules; the oxidation of glucose to produce ATP
what is the function of the reduced coenzymes? - 🧠ANSWER ✔✔They are
used to transfer energy to another compound
Describe the function of oxidation-reduction reactions in the synthesis of
ATP. - 🧠ANSWER ✔✔The reaction that transports energy to reduced
coenzymes for synthesis of ATP
How are hydrogen atoms involved the redox reactions? - 🧠ANSWER
✔✔When redox reactions take place they usually involve the loss of
hydrogen atoms.
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
1
STATEMENT. ALL RIGHTS RESERVED
,What happens to the energy stored within the newly formed reduced
coenzyme? Why is this referred to as phosphorylation? - 🧠ANSWER
✔✔Phosphorylation is the addition of a phosphate group to a molecule.
Name the four steps in cell 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
glycolysis.
Where does glycolysis occur? - 🧠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? - 🧠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+
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
2
STATEMENT. ALL RIGHTS RESERVED
, 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 that result in the formation of acetyl Co-enzyme A. -
🧠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? - 🧠ANSWER ✔✔2 - Glycolysis, 4 - Krebs cycle
How many ATP are produced during the Krebs cycle? - 🧠ANSWER ✔✔2
What happens to the remainder of the energy harvested through the Krebs
cycle? - 🧠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? - 🧠ANSWER ✔✔The
production of reduced co-enzymes.
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
3
STATEMENT. ALL RIGHTS RESERVED
