NSG 5003 Cell Biology, Metabolism, and Fluid–Electrolyte
Balance Comprehensive Exam Questions and Correct
Answers
1. Which process requires energy to move molecules against a concentration gradient?
a) Diffusion
b) Osmosis
c) Active transport
d) Filtration
Answer: c) Active transport
Active transport uses ATP to move substances against their concentration gradient. A
classic example is the sodium–potassium pump. This process is essential for maintaining
membrane potential and cellular homeostasis.
2. Endocytosis is a process in which:
a) Cells secrete proteins
b) Cells engulf extracellular material
c) Cells produce ATP
d) Cells divide
Answer: b) Cells engulf extracellular material
Endocytosis allows cells to take in nutrients and large particles. It involves vesicle
formation from the plasma membrane. Types include phagocytosis and pinocytosis.
3. Exocytosis is:
a) Cell engulfing materials
b) Cell releasing materials to the extracellular space
c) ATP production
d) Protein synthesis
Answer: b) Cell releasing materials to the extracellular space
Exocytosis expels substances such as hormones and neurotransmitters. Vesicles fuse with
the cell membrane to release contents. This process is essential for cell communication.
4. Which statement describes autophagy?
a) Cell division
b) Self-digestion of damaged organelles
c) Energy production
d) Protein synthesis
Answer: b) Self-digestion of damaged organelles
Autophagy allows cells to recycle damaged components. It is especially active during
stress or starvation. This process supports cellular survival and balance.
5. Which process produces ATP in the absence of oxygen?
a) Oxidative phosphorylation
b) Glycolysis
c) Electron transport chain
d) Krebs cycle
, Answer: b) Glycolysis
Glycolysis occurs in the cytoplasm and does not require oxygen. It produces a net gain of
2 ATP per glucose molecule. Under anaerobic conditions, pyruvate becomes lactate.
6. The Krebs cycle occurs in:
a) Nucleus
b) Mitochondrial matrix
c) Cytoplasm
d) Lysosome
Answer: b) Mitochondrial matrix
The Krebs cycle oxidizes acetyl-CoA to generate electron carriers. These carriers feed the
electron transport chain. It is central to aerobic metabolism.
7. The electron transport chain occurs in:
a) Outer mitochondrial membrane
b) Inner mitochondrial membrane
c) Cytoplasm
d) Nucleolus
Answer: b) Inner mitochondrial membrane
The ETC transfers electrons to oxygen to form water. This process generates most
cellular ATP. Oxygen is the final electron acceptor.
8. Which ion is the main intracellular cation?
a) Sodium
b) Potassium
c) Calcium
d) Chloride
Answer: b) Potassium
Potassium maintains intracellular osmolality and membrane potential. It is critical for
nerve and muscle function. Abnormal levels affect cardiac rhythm.
9. Sodium is:
a) Main extracellular cation
b) Main intracellular cation
c) Minor ion
d) Only in bones
Answer: a) Main extracellular cation
Sodium controls extracellular fluid volume. It plays a major role in nerve conduction.
Aldosterone tightly regulates sodium balance.
10. Calcium homeostasis is regulated by:
a) ADH and aldosterone
b) PTH, vitamin D, and calcitonin
c) Insulin only
d) Thyroxine only
Answer: b) PTH, vitamin D, and calcitonin
These hormones regulate calcium absorption and storage. They act on bone, kidneys, and
intestines. Proper balance is vital for neuromuscular function.
11. Magnesium functions include:
a) Enzyme cofactor and intracellular cation
b) Only structural
, c) Only extracellular
d) Not essential
Answer: a) Enzyme cofactor and intracellular cation
Magnesium stabilizes ATP and supports enzyme activity. It affects neuromuscular
transmission. Deficiency can cause tremors and arrhythmias.
12. Phosphate functions include:
a) Energy production, acid–base buffering, skeletal function
b) Only nerve signaling
c) Only bones
d) Only electrolytes
Answer: a) Energy production, acid–base buffering, skeletal function
Phosphate is a key component of ATP. It helps maintain pH balance. It also contributes
to bone mineralization.
13. True or False: Sodium is primarily regulated by PTH, vitamin D, and calcitonin.
Answer: False
Sodium is regulated mainly by aldosterone and the kidneys. PTH and vitamin D regulate
calcium and phosphate. Hormonal control maintains fluid balance.
14. Acidosis occurs when:
a) Plasma H⁺ exceeds normal range
b) Plasma Na⁺ exceeds normal range
c) Plasma K⁺ exceeds normal range
d) Plasma Ca²⁺ exceeds normal range
Answer: a) Plasma H⁺ exceeds normal range
Excess hydrogen ions lower blood pH. Acidosis impairs enzyme and cardiac function. It
may be metabolic or respiratory in origin.
15. Alkalosis occurs when:
a) Excess base or low hydrogen concentration
b) Excess acid
c) Sodium rises
d) Potassium drops
Answer: a) Excess base or low hydrogen concentration
Alkalosis raises blood pH above normal. It increases neuromuscular excitability. Severe
cases can cause arrhythmias.
16. Respiratory acidosis results from:
a) Hypoventilation
b) Hyperventilation
c) Excess bicarbonate
d) Sodium loss
Answer: a) Hypoventilation
Reduced ventilation causes CO₂ retention. CO₂ increases hydrogen ion concentration.
Common causes include COPD and drug overdose.
17. Respiratory alkalosis results from:
a) Hyperventilation
b) Hypoventilation
c) Bicarbonate loss
d) Sodium loss
Balance Comprehensive Exam Questions and Correct
Answers
1. Which process requires energy to move molecules against a concentration gradient?
a) Diffusion
b) Osmosis
c) Active transport
d) Filtration
Answer: c) Active transport
Active transport uses ATP to move substances against their concentration gradient. A
classic example is the sodium–potassium pump. This process is essential for maintaining
membrane potential and cellular homeostasis.
2. Endocytosis is a process in which:
a) Cells secrete proteins
b) Cells engulf extracellular material
c) Cells produce ATP
d) Cells divide
Answer: b) Cells engulf extracellular material
Endocytosis allows cells to take in nutrients and large particles. It involves vesicle
formation from the plasma membrane. Types include phagocytosis and pinocytosis.
3. Exocytosis is:
a) Cell engulfing materials
b) Cell releasing materials to the extracellular space
c) ATP production
d) Protein synthesis
Answer: b) Cell releasing materials to the extracellular space
Exocytosis expels substances such as hormones and neurotransmitters. Vesicles fuse with
the cell membrane to release contents. This process is essential for cell communication.
4. Which statement describes autophagy?
a) Cell division
b) Self-digestion of damaged organelles
c) Energy production
d) Protein synthesis
Answer: b) Self-digestion of damaged organelles
Autophagy allows cells to recycle damaged components. It is especially active during
stress or starvation. This process supports cellular survival and balance.
5. Which process produces ATP in the absence of oxygen?
a) Oxidative phosphorylation
b) Glycolysis
c) Electron transport chain
d) Krebs cycle
, Answer: b) Glycolysis
Glycolysis occurs in the cytoplasm and does not require oxygen. It produces a net gain of
2 ATP per glucose molecule. Under anaerobic conditions, pyruvate becomes lactate.
6. The Krebs cycle occurs in:
a) Nucleus
b) Mitochondrial matrix
c) Cytoplasm
d) Lysosome
Answer: b) Mitochondrial matrix
The Krebs cycle oxidizes acetyl-CoA to generate electron carriers. These carriers feed the
electron transport chain. It is central to aerobic metabolism.
7. The electron transport chain occurs in:
a) Outer mitochondrial membrane
b) Inner mitochondrial membrane
c) Cytoplasm
d) Nucleolus
Answer: b) Inner mitochondrial membrane
The ETC transfers electrons to oxygen to form water. This process generates most
cellular ATP. Oxygen is the final electron acceptor.
8. Which ion is the main intracellular cation?
a) Sodium
b) Potassium
c) Calcium
d) Chloride
Answer: b) Potassium
Potassium maintains intracellular osmolality and membrane potential. It is critical for
nerve and muscle function. Abnormal levels affect cardiac rhythm.
9. Sodium is:
a) Main extracellular cation
b) Main intracellular cation
c) Minor ion
d) Only in bones
Answer: a) Main extracellular cation
Sodium controls extracellular fluid volume. It plays a major role in nerve conduction.
Aldosterone tightly regulates sodium balance.
10. Calcium homeostasis is regulated by:
a) ADH and aldosterone
b) PTH, vitamin D, and calcitonin
c) Insulin only
d) Thyroxine only
Answer: b) PTH, vitamin D, and calcitonin
These hormones regulate calcium absorption and storage. They act on bone, kidneys, and
intestines. Proper balance is vital for neuromuscular function.
11. Magnesium functions include:
a) Enzyme cofactor and intracellular cation
b) Only structural
, c) Only extracellular
d) Not essential
Answer: a) Enzyme cofactor and intracellular cation
Magnesium stabilizes ATP and supports enzyme activity. It affects neuromuscular
transmission. Deficiency can cause tremors and arrhythmias.
12. Phosphate functions include:
a) Energy production, acid–base buffering, skeletal function
b) Only nerve signaling
c) Only bones
d) Only electrolytes
Answer: a) Energy production, acid–base buffering, skeletal function
Phosphate is a key component of ATP. It helps maintain pH balance. It also contributes
to bone mineralization.
13. True or False: Sodium is primarily regulated by PTH, vitamin D, and calcitonin.
Answer: False
Sodium is regulated mainly by aldosterone and the kidneys. PTH and vitamin D regulate
calcium and phosphate. Hormonal control maintains fluid balance.
14. Acidosis occurs when:
a) Plasma H⁺ exceeds normal range
b) Plasma Na⁺ exceeds normal range
c) Plasma K⁺ exceeds normal range
d) Plasma Ca²⁺ exceeds normal range
Answer: a) Plasma H⁺ exceeds normal range
Excess hydrogen ions lower blood pH. Acidosis impairs enzyme and cardiac function. It
may be metabolic or respiratory in origin.
15. Alkalosis occurs when:
a) Excess base or low hydrogen concentration
b) Excess acid
c) Sodium rises
d) Potassium drops
Answer: a) Excess base or low hydrogen concentration
Alkalosis raises blood pH above normal. It increases neuromuscular excitability. Severe
cases can cause arrhythmias.
16. Respiratory acidosis results from:
a) Hypoventilation
b) Hyperventilation
c) Excess bicarbonate
d) Sodium loss
Answer: a) Hypoventilation
Reduced ventilation causes CO₂ retention. CO₂ increases hydrogen ion concentration.
Common causes include COPD and drug overdose.
17. Respiratory alkalosis results from:
a) Hyperventilation
b) Hypoventilation
c) Bicarbonate loss
d) Sodium loss
