📝 Step 5 — KMU Past Papers & Exam Learning

This section contains KMU-style past paper questions designed to strengthen conceptual understanding. Focus on understanding explanations rather than memorizing answers.

🎯 How to Study KMU Past Papers

• Read the question carefully.
• Think about the answer before looking.
• Read the explanation slowly.
• Understand the reasoning behind the correct answer.
• Revise difficult questions again.

MCQ 1

Question:
A glycogen molecule allows rapid release of glucose during stress because it possesses:

Options:
Large numbers of reducing ends
Multiple non-reducing ends
Extensive peptide cross links
Alternating β-glycosidic bonds
Continuous phosphodiester bridges

Correct Answer:
Multiple non-reducing ends

Explanation:
Branching creates numerous non-reducing ends where glycogen phosphorylase acts simultaneously, enabling rapid glucose mobilization.

MCQ 2

Question:
During prolonged fasting, a child develops severe hypoglycemia despite normal muscle glycogen stores. Which hepatic feature is most likely defective?

Options:
Formation of UDP-glucose
Activity of glycogenin protein
Conversion of glucose-6-phosphate to glucose
Synthesis of α-1,6 glycosidic bonds
Transport of glucose into hepatocytes

Correct Answer:
Conversion of glucose-6-phosphate to glucose

Explanation:
Liver contains glucose-6-phosphatase which releases free glucose into blood. Deficiency causes fasting hypoglycemia.

MCQ 3

Question:
The highly branched structure of glycogen is most beneficial for which physiological purpose?

Options:
Reduction of intracellular calcium concentration
Facilitation of rapid glucose mobilization
Enhancement of mitochondrial ATP synthesis
Prevention of glucose absorption from intestine
Promotion of fatty acid oxidation in liver

Correct Answer:
Facilitation of rapid glucose mobilization

Explanation:
Branching increases enzyme access points, allowing rapid glycogen synthesis and degradation.

MCQ 4

Question:
A muscle biopsy from an athlete demonstrates abundant glycogen granules near myofibrils. The major functional significance of this arrangement is:

Options:
Maintenance of plasma glucose level
Generation of amino acids during exercise
Rapid ATP production during contraction
Enhancement of ketone body synthesis
Activation of gluconeogenesis pathways

Correct Answer:
Rapid ATP production during contraction

Explanation:
Muscle glycogen provides a rapid local source of glucose for ATP production during contraction.

MCQ 5

Question:
A defect in branching enzyme would most directly alter which structural characteristic of glycogen?

Options:
Length of peptide linkage
Formation of α-1,6 bonds
Attachment of phosphate groups
Transport into lysosomes
Conversion into fructose polymers

Correct Answer:
Formation of α-1,6 bonds

Explanation:
Branching enzyme forms α-1,6 glycosidic bonds responsible for glycogen branching.

MCQ 6

Question:
Which feature distinguishes liver glycogen metabolism from muscle glycogen metabolism?

Options:
Presence of glycogen synthase
Formation of glucose-1-phosphate
Storage within cytoplasmic granules
Ability to release free glucose into blood
Requirement for phosphoglucomutase activity

Correct Answer:
Ability to release free glucose into blood

Explanation:
Liver contains glucose-6-phosphatase, enabling release of free glucose into circulation.

MCQ 7

Question:
A patient with Andersen disease develops hepatomegaly due to accumulation of poorly branched glycogen. The abnormal glycogen is harmful primarily because it:

Options:
Becomes excessively soluble in plasma
Interferes with cellular architecture
Enhances mitochondrial respiration
Accelerates membrane transport activity
Stimulates uncontrolled insulin release

Correct Answer:
Interferes with cellular architecture

Explanation:
Poorly branched glycogen forms insoluble aggregates that disrupt hepatocyte structure and function.

MCQ 8

Question:
During glycogenesis, activation of glucose before polymer formation requires:

Options:
CTP hydrolysis
ATP deamination
UTP utilization
GTP phosphorylation
NADPH oxidation

Correct Answer:
UTP utilization

Explanation:
UDP-glucose formation requires UTP and provides activated glucose for glycogen synthesis.

MCQ 9

Question:
An inherited defect prevents initiation of glycogen synthesis despite normal glycogen synthase activity. Which molecule is most likely deficient?

Options:
Glycogenin
Hexokinase
Glucokinase
Phosphorylase kinase
Glucose transporter-2

Correct Answer:
Glycogenin

Explanation:
Glycogenin acts as the primer protein that initiates glycogen formation.

MCQ 10

Question:
The compact nature of glycogen polymer is physiologically important because it:

Options:
Increases intracellular osmotic pressure
Facilitates glucose diffusion into nucleus
Permits storage of large glucose quantities safely
Promotes direct ATP formation in cytoplasm
Enhances glucose filtration through kidney

Correct Answer:
Permits storage of large glucose quantities safely

Explanation:
Polymerization of glucose into glycogen reduces osmotic stress while allowing efficient storage.

MCQ 11

Question:
A patient experiences muscle cramps after intense exercise but maintains normal fasting blood glucose. Which tissue-specific glycogen function remains intact?

Options:
Muscle ATP generation
Local glucose utilization
Exercise-related glycogenolysis
Maintenance of blood glucose
Rapid glycolytic activation

Correct Answer:
Maintenance of blood glucose

Explanation:
Liver glycogen maintains blood glucose, while muscle glycogen mainly supports contraction.

MCQ 12

Question:
Which enzyme directly elongates glycogen chains during glycogenesis?

Options:
Branching enzyme
Glycogen synthase
Glucose-6-phosphatase
Glycogen phosphorylase
UDP-glucose pyrophosphorylase

Correct Answer:
Glycogen synthase

Explanation:
Glycogen synthase adds glucose residues through α-1,4 glycosidic linkages.

MCQ 13

Question:
The absence of glucose-6-phosphatase in skeletal muscle explains why muscle glycogen cannot:

Options:
Undergo branching reactions
Store activated glucose
Produce ATP anaerobically
Release free glucose into circulation
Form glucose-1-phosphate molecules

Correct Answer:
Release free glucose into circulation

Explanation:
Without glucose-6-phosphatase, muscle cannot convert glucose-6-phosphate into free glucose.

MCQ 14

Question:
Following a carbohydrate-rich meal, insulin promotes glycogenesis mainly by activating:

Options:
Glycogen phosphorylase
Glucose-6-phosphatase
Glycogen synthase
Pyruvate carboxylase
Hormone-sensitive lipase

Correct Answer:
Glycogen synthase

Explanation:
Insulin activates glycogen synthase, promoting glucose storage as glycogen.

MCQ 15

Question:
The spherical branching arrangement of glycogen primarily enhances:

Options:
Membrane receptor signaling
Simultaneous enzyme accessibility
Mitochondrial oxidative phosphorylation
Passive glucose transport
Nuclear transcription activity

Correct Answer:
Simultaneous enzyme accessibility

Explanation:
Multiple branch ends allow enzymes to act simultaneously, increasing metabolic efficiency.

MCQ 16

Question:
A child develops fasting hypoglycemia and hepatomegaly due to impaired glycogen storage. Which metabolic role of liver glycogen is most affected?

Options:
Storage of amino acids
Detoxification of ammonia
Maintenance of blood glucose homeostasis
Production of ketone bodies
Synthesis of plasma proteins

Correct Answer:
Maintenance of blood glucose homeostasis

Explanation:
Liver glycogen maintains blood glucose during fasting by releasing glucose into circulation.

MCQ 17

Question:
The conversion of glucose-6-phosphate into glucose-1-phosphate during glycogenesis is catalyzed by:

Options:
Hexokinase
Phosphoglucomutase
Branching enzyme
Glucose-6-phosphatase
UDP-glucose pyrophosphorylase

Correct Answer:
Phosphoglucomutase

Explanation:
Phosphoglucomutase interconverts glucose-6-phosphate and glucose-1-phosphate.

MCQ 18

Question:
Which characteristic of glycogen best explains its rapid mobilization compared with starch?

Options:
Lower molecular weight
Presence of peptide residues
Higher degree of branching
Increased phosphate content
Localization within lysosomes

Correct Answer:
Higher degree of branching

Explanation:
Glycogen is more highly branched than starch, allowing faster enzymatic degradation.

MCQ 19

Question:
A patient with Pompe disease develops cardiomegaly due to glycogen accumulation within lysosomes. The underlying defect involves deficiency of:

Options:
Branching enzyme
Acid maltase
Glucose transporter-4
Phosphorylase kinase
UDP-glucose pyrophosphorylase

Correct Answer:
Acid maltase

Explanation:
Pompe disease results from lysosomal acid maltase deficiency causing glycogen accumulation in tissues.

MCQ 20

Question:
During glycogenesis, failure of UDP-glucose formation would most directly impair:

Options:
Initiation of β-oxidation
Activation of glucose for polymer synthesis
Conversion of glycogen into glucose
Release of glucose into blood
Formation of pyruvate from lactate

Correct Answer:
Activation of glucose for polymer synthesis

Explanation:
UDP-glucose is the activated glucose donor required for glycogen chain elongation.

📌 Important Exam Strategy

KMU examinations often test integrated understanding rather than isolated facts. Focus on linking anatomy, embryology, histology, and clinical concepts when reviewing questions.

✅ Revision Tip

If you can explain the reason behind the correct answer without looking at notes, your concept is strong.