MFN-002 Solved Assignment July 2025 | Nutritional Biochemistry | IGNOU MSCDFSM

Q: Answer the following sub-parts.

Answer available — download the full PDF for complete details.

Q: Answer the following sub-parts.

Answer available — download the full PDF for complete details.

Q1. Answer the following sub-parts.

(a)) What are monosaccharides? Explain any two properties of monosaccharides. (200 words)
(b)i) Explain the following terms: Saponification (100 words)
(b)ii) Explain the following terms: Rancidity (100 words)

Key Points:

Monosaccharides are simple, non-hydrolyzable carbohydrate units like glucose or fructose.
Monosaccharides are highly water-soluble due to numerous hydroxyl groups forming hydrogen bonds.
Most monosaccharides are reducing sugars, possessing a free carbonyl group for electron donation.
Saponification is the alkaline hydrolysis of triglycerides into glycerol and fatty acid salts (soap).

Answer: (a) Monosaccharides are the simplest form of carbohydrates, serving as fundamental energy sources and building blocks for larger carbohydrate molecules. They are single polyhydroxy aldehyde (aldose) or polyhydroxy ketone (ketose) units, typically comprising three to seven carbon atoms. Crucially, monosaccharides cannot be hydrolyzed into smaller carbohydrate compounds. Glucose, fructose, and galactose are common examples, vital for cellular metabolism. Two key properties include: 1. **Solubil...

Q2. Answer the following sub-parts.

(a)) What are Eicosonoids? Briefly describe their role in the body. (200 words)
(b)) Discuss the four basic structural levels of proteins, giving examples. (200 words)

Key Points:

Eicosanoids are 20-carbon fatty acid derivatives acting as local signaling molecules.
Eicosanoids (prostaglandins, thromboxanes, leukotrienes) mediate inflammation, pain, blood clotting, immunity.
Primary protein structure is the amino acid sequence linked by peptide bonds (e.g., insulin).
Secondary protein structure involves local folding like α-helices and β-sheets via H-bonds (e.g., keratin).

Answer: Eicosanoids are potent signaling molecules derived from specific 20-carbon fatty acids, primarily arachidonic acid, acting locally to mediate a wide range of physiological processes. These include inflammation, pain, fever, and blood clotting. Proteins, the workhorses of the cell, exhibit a hierarchical organization of structure crucial for their diverse functions. This organization is described by four basic levels: primary, secondary, tertiary, and quaternary structure.

Q3. Answer the following sub-parts.

(a)) Discuss the properties and importance of following vitamins in our body: Vitamin C (200 words)
(b)) Discuss the properties and importance of following vitamins in our body: Vitamin K (200 words)

Key Points:

Vitamin C (ascorbic acid) is water-soluble, crucial for collagen synthesis, antioxidant defense, and iron absorption.
Vitamin C deficiency causes scurvy, characterized by impaired wound healing and bleeding gums.
Vitamin K is fat-soluble, exists as K1 (plants) and K2 (bacteria/animal sources).
Vitamin K is essential for activating blood clotting factors (II, VII, IX, X) via gamma-carboxylation.

Answer: The following provides a comprehensive discussion on the properties and importance of Vitamin C and Vitamin K in the human body, drawing from nutritional biochemistry principles.

Q4. Answer the following sub-parts.

(a)) Explain the mechanism of enzyme action in our body. Enumerate the factors affecting enzyme activity. (200 words)
(b)) Explain the process of absorption of amino acids and peptides in our body. (200 words)

Key Points:

Enzymes are biological catalysts lowering activation energy by forming enzyme-substrate complex at active site.
Induced-fit model: active site dynamically adjusts to fit substrate for optimal reaction.
Enzyme activity affected by temperature (optimal 37°C), pH (optimal specific), substrate/enzyme concentration, inhibitors.
Free amino acids absorbed by secondary active transport (Na⁺-dependent) via specific carriers in small intestine.

Answer: Enzymes are biological catalysts that significantly accelerate biochemical reactions within the body by lowering the activation energy, without being consumed themselves. This process begins with the formation of an enzyme-substrate (ES) complex where the substrate binds to the enzyme's active site. The induced-fit model explains how the active site is flexible and adjusts its shape to precisely accommodate the substrate, optimizing their interaction and facilitating the reaction. Following the...

Q5. Answer the following sub-parts.

(a)) What is gluconeogenesis? Discuss the four substrates used in gluconeogenesis. (200 words)
(b)) What are the components of the electron transport chain? Explain briefly. (200 words)

Key Points:

Gluconeogenesis synthesizes glucose from non-carbohydrate precursors.
Key gluconeogenesis substrates: lactate, glucogenic amino acids, glycerol, propionyl CoA.
Electron Transport Chain (ETC) produces ATP via oxidative phosphorylation.
ETC components include Complexes I, II, III, IV, Coenzyme Q, and Cytochrome c.

Answer: Nutritional biochemistry involves crucial metabolic pathways like gluconeogenesis, which synthesizes glucose from non-carbohydrate precursors, and the electron transport chain, which is central to ATP production. Gluconeogenesis is vital during fasting or strenuous exercise to maintain blood glucose levels, utilizing substrates such as lactate, glucogenic amino acids, glycerol, and propionyl CoA. Concurrently, the electron transport chain, composed of four protein complexes and two mobile carrie...

Q6. Answer the following sub-parts.

(a)) How cholesterol is metabolized in our body? Explain. (200 words)
(b)i) Differentiate between the following sets of terms: LDL and HDL (100 words)
(b)ii) Differentiate between the following sets of terms: Ketogenic and Glucogenic amino acid (100 words)

Key Points:

Cholesterol synthesis starts from acetyl-CoA, regulated by HMG-CoA reductase.
LDL transports cholesterol to peripheral tissues, linked to atherosclerosis ('bad cholesterol').
HDL removes excess cholesterol from tissues for liver excretion ('good cholesterol').
Glucogenic amino acids form glucose precursors (e.g., pyruvate, oxaloacetate).

Answer:

Q7. Answer the following sub-parts.

(a)) Briefly describe synthesis of Pyrimidine in our body. (200 words)
(b)) How and where toxic ammonia is converted into urea in our body? Explain briefly. (200 words)

Key Points:

Pyrimidine synthesis starts with glutamine, CO₂, and aspartate, forming UMP as a key intermediate.
Carbamoyl Phosphate Synthetase II (CPS II) is the rate-limiting enzyme in pyrimidine *de novo* synthesis.
Toxic ammonia is detoxified into urea through the Urea Cycle in the liver.
The Urea Cycle occurs partly in the mitochondria and partly in the cytosol of liver cells.

Answer: The body efficiently synthesizes essential biomolecules like pyrimidines and detoxifies harmful metabolic byproducts such as ammonia through highly regulated enzymatic pathways. Pyrimidine synthesis, crucial for DNA, RNA, and coenzyme formation, occurs *de novo* primarily in the cytosol. Concurrently, toxic ammonia, generated from amino acid catabolism, is safely converted into non-toxic urea in the liver via the urea cycle, ensuring its excretion without causing systemic toxicity. These proces...

Q8. Answer the following sub-parts.

(a)) Define free radicals. Explain physiological mechanisms to limit free radical damage. (200 words)
(b)) What is the composition and function of chylomicron? (200 words)

Key Points:

Free radicals are reactive molecules with unpaired electrons, causing oxidative cellular damage.
Enzymatic antioxidants (SOD, Catalase, GPx) detoxify free radicals in the body.
Non-enzymatic antioxidants include Vitamin E, C, minerals (Se, Zn), and phytochemicals.
Chylomicrons are large lipoproteins primarily transporting dietary triglycerides.

Answer:

Q9. Answer the following sub-parts.

(a)i) Describe functions of following minerals: Calcium (100 words)
(a)ii) Describe functions of following minerals: Iron (100 words)
(b)i) Briefly enumerate biochemical role of following hormones: Insulin (100 words)
(b)ii) Briefly enumerate biochemical role of following hormones: Glucocorticoids (100 words)

Key Points:

Calcium forms bones/teeth, enables muscle contraction, nerve transmission, blood clotting.
Iron transports oxygen (hemoglobin), stores it (myoglobin), and functions in energy enzymes.
Insulin lowers blood glucose, promotes glucose uptake, glycogenesis, and lipogenesis.
Glucocorticoids raise blood glucose via gluconeogenesis, inhibit glucose use, are anti-inflammatory.

Answer: Minerals like Calcium and Iron are vital for structural integrity and numerous metabolic functions, while hormones such as Insulin and Glucocorticoids precisely regulate key biochemical pathways, particularly glucose metabolism. Calcium is indispensable for bone and teeth formation, providing essential structural support. It also plays crucial roles in cellular signaling, muscle contraction, and nerve impulse transmission. Iron is primarily known for its central role in oxygen transport via hem...

Q10. Answer the following sub-parts.

(a)) List the common inborn errors due to carbohydrate metabolism. Explain briefly any two of them. (200 words)
(b)) Define haemoglobinopathies. Elaborate any one in detail. (200 words)

Key Points:

Galactosemia results from GALT enzyme deficiency, causing toxic galactose metabolite accumulation.
Von Gierke's disease (GSD Type I) is due to glucose-6-phosphatase deficiency, leading to severe hypoglycemia.
Haemoglobinopathies are genetic disorders affecting haemoglobin structure or synthesis.
Sickle Cell Anemia is caused by a point mutation (Glu→Val) in the β-globin gene, forming HbS.

Answer: Inborn errors of metabolism often involve enzyme deficiencies that disrupt crucial biochemical pathways, leading to the accumulation of toxic substrates or deficiencies in essential products. These genetic disorders manifest differently based on the affected pathway and the specific enzyme involved. For carbohydrates, these errors impact glucose homeostasis and energy supply, while for proteins like haemoglobin, structural or synthetic defects lead to compromised oxygen transport and cellular in...

Q1. Explain the following in 2-3 sentences. Also give the structure wherever possible.

(a)) Recombinant DNA (40 words)
(b)) Mutarotation (40 words)
(c)) Sterols (40 words)
(d)) Zwitterion (40 words)
(e)) Holoenzyme (40 words)
(f)) Competitive inhibition (40 words)
(g)) Coenzyme A (40 words)
(h)) Chiral carbon atom (40 words)
(i)) Micelle (40 words)
(j)) Glycolysis (40 words)

Key Points:

Monosaccharides are simple, non-hydrolyzable carbohydrate units like glucose or fructose.
Monosaccharides are highly water-soluble due to numerous hydroxyl groups forming hydrogen bonds.
Most monosaccharides are reducing sugars, possessing a free carbonyl group for electron donation.
Saponification is the alkaline hydrolysis of triglycerides into glycerol and fatty acid salts (soap).

Q2. Name the defective enzyme in the following diseases:

(a)) Alcaptonuria (20 words)
(b)) Gaucher's disease (20 words)
(c)) Homocystinuria (20 words)
(d)) Pentosuria (20 words)
(e)) Albinism (20 words)

Key Points:

Eicosanoids are 20-carbon fatty acid derivatives acting as local signaling molecules.
Eicosanoids (prostaglandins, thromboxanes, leukotrienes) mediate inflammation, pain, blood clotting, immunity.
Primary protein structure is the amino acid sequence linked by peptide bonds (e.g., insulin).
Secondary protein structure involves local folding like α-helices and β-sheets via H-bonds (e.g., keratin).

Q3. Give the significance/role of following:

(a)) Conversion of IMP to AMP (30 words)
(b)) Vitamin B6 in transamination (30 words)
(c)) Oxygen free radicals (30 words)
(d)) Phenylalanine hydroxylase (30 words)
(e)) Fight or flight response (30 words)

Key Points:

Vitamin C (ascorbic acid) is water-soluble, crucial for collagen synthesis, antioxidant defense, and iron absorption.
Vitamin C deficiency causes scurvy, characterized by impaired wound healing and bleeding gums.
Vitamin K is fat-soluble, exists as K1 (plants) and K2 (bacteria/animal sources).
Vitamin K is essential for activating blood clotting factors (II, VII, IX, X) via gamma-carboxylation.

Answer: The following provides a comprehensive discussion on the properties and importance of Vitamin C and Vitamin K in the human body, drawing from nutritional biochemistry principles.

MFN-002 Solved Assignment — July 2025

Nutritional Biochemistry | IGNOU Master of Science in Dietetics and Food Service Management M.Sc. (DFSM) (MSCDFSM)

MFN-002—July 2025

Nutritional Biochemistry

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MFN-002 Assignment Questions — July 2025

Q1. Answer the following sub-parts.

Q2. Answer the following sub-parts.

Q3. Answer the following sub-parts.

Q4. Answer the following sub-parts.

Q5. Answer the following sub-parts.

Q6. Answer the following sub-parts.

Q7. Answer the following sub-parts.

Q8. Answer the following sub-parts.

Q9. Answer the following sub-parts.

Q10. Answer the following sub-parts.

Q1. Explain the following in 2-3 sentences. Also give the structure wherever possible.

Q2. Name the defective enzyme in the following diseases:

Q3. Give the significance/role of following: