NSG 5003: Comprehensive Cellular, Fluid, and
Electrolyte Exam Questions and Answers
1. Which organelle is the site of lipid and steroid synthesis and detoxification?
a) Rough endoplasmic reticulum
b) Smooth endoplasmic reticulum
c) Golgi apparatus
d) Mitochondria
Answer: b) Smooth endoplasmic reticulum
The smooth ER synthesizes lipids and steroids, metabolizes drugs, and detoxifies
chemicals. It lacks ribosomes, unlike rough ER, which is involved in protein synthesis.
Proper smooth ER function is essential for cell metabolism and detoxification.
2. Ribosomes are responsible for:
a) Packaging proteins
b) Synthesizing proteins
c) Producing ATP
d) Storing calcium
Answer: b) Synthesizing proteins
Ribosomes translate mRNA into polypeptides. They can be free in the cytoplasm or
attached to the rough ER. Proper protein synthesis is essential for cell structure and
function.
3. Lysosomes primarily function to:
a) Generate energy
b) Digest and recycle cellular waste
c) Package proteins
d) Produce ribosomes
Answer: b) Digest and recycle cellular waste
Lysosomes contain hydrolytic enzymes that break down macromolecules, damaged
organelles, and pathogens. They are essential for cellular cleanup and homeostasis.
4. Peroxisomes function mainly to:
a) Store calcium
b) Break down fatty acids and detoxify harmful substances
c) Produce ATP
d) Assemble ribosomes
Answer: b) Break down fatty acids and detoxify harmful substances
Peroxisomes contain enzymes like catalase to metabolize fatty acids and reactive oxygen
species. They protect the cell from oxidative damage.
5. The cytoskeleton is composed of:
a) Microfilaments, intermediate filaments, and microtubules
b) Lipids only
c) Carbohydrates only
d) Ribosomes
, Answer: a) Microfilaments, intermediate filaments, and microtubules
The cytoskeleton maintains cell shape, provides mechanical support, and facilitates
intracellular transport and motility. Disruption can impair cellular function.
6. 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 solutes across membranes. Examples include the
sodium-potassium pump. It is essential for maintaining ionic gradients.
7. 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 the cell to internalize nutrients, fluids, and pathogens. It includes
phagocytosis (solid particles) and pinocytosis (fluids).
8. 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 allows secretion of hormones, neurotransmitters, and waste products. Vesicles
fuse with the plasma membrane to release contents.
9. 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 components during stress. It maintains cellular
homeostasis and prevents accumulation of damaged organelles.
10. 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 produces 2 ATP per glucose molecule without
oxygen. Pyruvate is converted to lactate under anaerobic conditions.
11. 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 produce NADH, FADH₂, and ATP. It is central
to aerobic energy production.
12. 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 from NADH and FADH₂ to oxygen, generating ATP.
Oxygen acts as the final electron acceptor.
13. Which ion is the main intracellular cation?
a) Sodium
b) Potassium
c) Calcium
d) Chloride
Answer: b) Potassium
Potassium maintains resting membrane potential, intracellular osmolality, and glycogen
deposition. Imbalances can affect cardiac and neuromuscular function.
14. Sodium is:
a) Main extracellular cation
b) Main intracellular cation
c) Minor ion
d) Only in bones
Answer: a) Main extracellular cation
Sodium regulates extracellular fluid volume, nerve conduction, and muscle function. It is
balanced by aldosterone and renal mechanisms.
15. 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 control calcium absorption, bone deposition, and renal reabsorption.
Proper regulation is essential for bones, nerves, and muscles.
16. 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 is vital for neuromuscular function, enzyme activity, and ATP utilization.
PTH regulates magnesium levels.
Electrolyte Exam Questions and Answers
1. Which organelle is the site of lipid and steroid synthesis and detoxification?
a) Rough endoplasmic reticulum
b) Smooth endoplasmic reticulum
c) Golgi apparatus
d) Mitochondria
Answer: b) Smooth endoplasmic reticulum
The smooth ER synthesizes lipids and steroids, metabolizes drugs, and detoxifies
chemicals. It lacks ribosomes, unlike rough ER, which is involved in protein synthesis.
Proper smooth ER function is essential for cell metabolism and detoxification.
2. Ribosomes are responsible for:
a) Packaging proteins
b) Synthesizing proteins
c) Producing ATP
d) Storing calcium
Answer: b) Synthesizing proteins
Ribosomes translate mRNA into polypeptides. They can be free in the cytoplasm or
attached to the rough ER. Proper protein synthesis is essential for cell structure and
function.
3. Lysosomes primarily function to:
a) Generate energy
b) Digest and recycle cellular waste
c) Package proteins
d) Produce ribosomes
Answer: b) Digest and recycle cellular waste
Lysosomes contain hydrolytic enzymes that break down macromolecules, damaged
organelles, and pathogens. They are essential for cellular cleanup and homeostasis.
4. Peroxisomes function mainly to:
a) Store calcium
b) Break down fatty acids and detoxify harmful substances
c) Produce ATP
d) Assemble ribosomes
Answer: b) Break down fatty acids and detoxify harmful substances
Peroxisomes contain enzymes like catalase to metabolize fatty acids and reactive oxygen
species. They protect the cell from oxidative damage.
5. The cytoskeleton is composed of:
a) Microfilaments, intermediate filaments, and microtubules
b) Lipids only
c) Carbohydrates only
d) Ribosomes
, Answer: a) Microfilaments, intermediate filaments, and microtubules
The cytoskeleton maintains cell shape, provides mechanical support, and facilitates
intracellular transport and motility. Disruption can impair cellular function.
6. 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 solutes across membranes. Examples include the
sodium-potassium pump. It is essential for maintaining ionic gradients.
7. 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 the cell to internalize nutrients, fluids, and pathogens. It includes
phagocytosis (solid particles) and pinocytosis (fluids).
8. 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 allows secretion of hormones, neurotransmitters, and waste products. Vesicles
fuse with the plasma membrane to release contents.
9. 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 components during stress. It maintains cellular
homeostasis and prevents accumulation of damaged organelles.
10. 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 produces 2 ATP per glucose molecule without
oxygen. Pyruvate is converted to lactate under anaerobic conditions.
11. 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 produce NADH, FADH₂, and ATP. It is central
to aerobic energy production.
12. 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 from NADH and FADH₂ to oxygen, generating ATP.
Oxygen acts as the final electron acceptor.
13. Which ion is the main intracellular cation?
a) Sodium
b) Potassium
c) Calcium
d) Chloride
Answer: b) Potassium
Potassium maintains resting membrane potential, intracellular osmolality, and glycogen
deposition. Imbalances can affect cardiac and neuromuscular function.
14. Sodium is:
a) Main extracellular cation
b) Main intracellular cation
c) Minor ion
d) Only in bones
Answer: a) Main extracellular cation
Sodium regulates extracellular fluid volume, nerve conduction, and muscle function. It is
balanced by aldosterone and renal mechanisms.
15. 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 control calcium absorption, bone deposition, and renal reabsorption.
Proper regulation is essential for bones, nerves, and muscles.
16. 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 is vital for neuromuscular function, enzyme activity, and ATP utilization.
PTH regulates magnesium levels.
