MFN 002
Nutritional Biochemistry
MFN 002 Solved Free Assignment 2023
IGNOU MFN 002 Solved Free Assignment January 2023
Q 1. a) Define isomers. Explain stereo isomerism and optical isomerism of monosaccharides in detail.
Ans. a) Isomers are molecules with the same molecular formula but different structural arrangements.
In the case of monosaccharides, stereo isomers have the same chemical formula but differ in the spatial arrangement of their atoms.
Optical isomers are a type of stereo isomers that differ in their ability to rotate plane-polarized light.
Stereo isomerism in monosaccharides occurs due to the asymmetric carbon (chiral center) in their molecule, which is a carbon atom attached to four different groups.
The spatial arrangement of these groups can differ, leading to two possible configurations: D and L. MFN 002 Solved Free Assignment 2023
In the D configuration, the -OH group on the chiral carbon is on the right-hand side of the Fischer projection, while in the L configuration, it is on the left-hand side.
Optical isomerism arises when these stereoisomers rotate plane-polarized light in opposite directions. Enantiomers are pairs of optical isomers that are mirror images of each other and rotate plane-polarized light in opposite directions.
The ability of an enantiomer to rotate plane-polarized light is measured by its specific rotation value.
b) List any two chemical properties of the following:
i) Fatty acids
ii) Proteins
Ans. b)
i) Two chemical properties of fatty acids are:
Reactivity: Fatty acids can undergo various chemical reactions, such as esterification, saponification, and oxidation.
For example, esterification with glycerol produces triacylglycerols, the main component of many dietary fats and oils.
Melting point: The melting point of fatty acids depends on their chain length and degree of unsaturation. MFN 002 Solved Free Assignment 2023
Saturated fatty acids have a higher melting point than unsaturated fatty acids due to the greater intermolecular forces of attraction between their molecules.
ii) Two chemical properties of proteins are:
Acidity and basicity: Proteins contain ionizable groups, such as the amino and carboxyl groups, which can act as acids or bases depending on the pH of the solution.
At their isoelectric point, proteins have a net charge of zero and are least soluble in water.
Denaturation: Proteins can be denatured by various agents, such as heat, pH extremes, detergents, and chaotropic agents.
Denaturation involves the disruption of the protein’s secondary, tertiary, or quaternary structure, leading to loss of function.
Q 2. a)Define protein and its monomeric unit. Give classification of amino acid with the structural formula.
Ans. a) Proteins are complex macromolecules that are essential for the structure, function, and regulation of cells and tissues.
The monomeric unit of a protein is an amino acid, which consists of an amino group (-NH2), a carboxyl group (-COOH), a hydrogen atom, and a side chain (R group) that varies in structure and properties.MFN 002 Solved Free Assignment 2023
Amino acids are classified based on the properties of their side chains. There are 20 standard amino acids that can be classified into four groups:
Nonpolar, aliphatic: glycine, alanine, valine, leucine, isoleucine, and proline
Aromatic: phenylalanine, tyrosine, and tryptophan
Polar, uncharged: serine, threonine, cysteine, asparagine, and glutamine
Charged: lysine, arginine, histidine, aspartate, and glutamate
b) Briefly describe physio chemical properties of fat-soluble vitamin.
Ans. Fat-soluble vitamins are a group of organic compounds that are insoluble in water and can be dissolved in fats and oils.
The four fat-soluble vitamins are vitamin A, D, E, and K. Physio-chemical properties of fat-soluble vitamins are:
Solubility: Fat-soluble vitamins are soluble in lipids, oils, and organic solvents but are insoluble in water. MFN 002 Solved Free Assignment 2023
Absorption: Fat-soluble vitamins are absorbed in the small intestine along with dietary lipids and are transported through the lymphatic system before entering the bloodstream.
Storage: Fat-soluble vitamins can be stored in the body’s adipose tissue and liver, and excessive intake can lead to toxicity.
Stability: Fat-soluble vitamins are sensitive to heat, light, and oxidation and can degrade over time.
Q 3. a) Define enzyme and coenzyme. Explain models for mechanism of enzyme action in detail with diagram.
Ans. Enzymes are biological catalysts that facilitate and accelerate biochemical reactions by lowering the activation energy required for the reaction to occur.
They are typically proteins that act on specific substrates, converting them into products.
Enzymes have a specific three-dimensional structure that allows them to interact with the substrate in a highly specific manner, forming an enzyme-substrate complex. MFN 002 Solved Free Assignment 2023
Coenzymes are small organic molecules that are required for enzyme activity. They work together with the enzyme to facilitate and regulate the reaction. Coenzymes are not proteins but are essential for the enzyme’s function.
Coenzymes can act as electron carriers, transferring electrons from one enzyme to another, or as carriers of functional groups that are transferred between substrates during the reaction.
The models for the mechanism of enzyme action are the Lock-and-Key model, the Induced Fit model, and the Transition State model.
The Lock-and-Key model proposes that the enzyme has a rigid active site that is complementary in shape to the substrate, and the two fit together like a lock and key.
The active site provides a specific environment that stabilizes the transition state of the reaction, lowering the activation energy required for the reaction to occur.
The Lock-and-Key model suggests that the enzyme-substrate complex is a static structure that does not change during the reaction.
The Induced Fit model proposes that the active site of the enzyme is flexible and can change its shape to accommodate the substrate.
The substrate binding induces a conformational change in the enzyme, which leads to a tighter fit between the enzyme and the substrate.
The Induced Fit model suggests that the enzyme-substrate complex is a dynamic structure that changes during the reaction.
The Transition State model proposes that the enzyme stabilizes the transition state of the reaction, which is the highest-energy intermediate in the reaction pathway.
The enzyme reduces the energy required for the reaction to proceed by providing an alternative reaction pathway with a lower activation energy.
The Transition State model suggests that the enzyme-substrate complex is a transient structure that exists only during the reaction.
In summary, enzymes are biological catalysts that accelerate biochemical reactions by lowering the activation energy required for the reaction to occur.
Coenzymes are small organic molecules that work together with the enzyme to facilitate and regulate the reaction. MFN 002 Solved Free Assignment 2023
The models for the mechanism of enzyme action are the Lock-and-Key model, the Induced Fit model, and the Transition State model, each proposing a different way in which enzymes facilitate the reaction.
b) What are essential fatty acids? Name any two essential fatty acids and their food sources.
Ans. Essential fatty acids (EFAs) are fatty acids that cannot be synthesized by the human body and must be obtained through the diet.
EFAs are important for maintaining optimal health and are involved in various physiological functions, including cell membrane structure and function, brain development, immune function, and inflammation regulation.
The two main types of EFAs are omega-3 fatty acids and omega-6 fatty acids.
Omega-3 fatty acids are polyunsaturated fatty acids (PUFAs) that have a double bond three carbons away from the methyl end of the fatty acid chain.
The two essential omega-3 fatty acids are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). EPA and DHA are mainly found in fatty fish, such as salmon, tuna, mackerel, and sardines.
Plant-based sources of omega-3 fatty acids include flaxseeds, chia seeds, hemp seeds, and walnuts. MFN 002 Solved Free Assignment 2023
Omega-6 fatty acids are PUFAs that have a double bond six carbons away from the methyl end of the fatty acid chain.
The two essential omega-6 fatty acids are linoleic acid (LA) and arachidonic acid (AA). LA is mainly found in vegetable oils, such as soybean oil, corn oil, and sunflower oil. AA is found in animal-based foods, such as meat, eggs, and dairy products.
A balanced intake of omega-3 and omega-6 fatty acids is important for maintaining optimal health.
The recommended intake of omega-3 fatty acids is 250-500 mg per day for adults, and the recommended intake of omega-6 fatty acids is 5-10% of total energy
Q 4. a) Explain urea cycle.
Ans. The urea cycle, also known as the ornithine cycle, is a vital process that occurs in the liver and helps to remove toxic ammonia from the body.
Ammonia is produced in the body as a byproduct of protein metabolism and is highly toxic to the brain and other organs.
Therefore, it is important to convert ammonia into a less toxic compound, such as urea, which can be safely excreted by the kidneys.
The urea cycle consists of five main steps, each catalyzed by a specific enzyme. The first step is the conversion of ammonia and carbon dioxide into carbamoyl phosphate by the enzyme carbamoyl phosphate synthetase I.
This reaction requires the input of two molecules of ATP and occurs in the mitochondria of liver cells. MFN 002 Solved Free Assignment 2023
The second step involves the transfer of the carbamoyl group from carbamoyl phosphate to the amino acid ornithine, forming citrulline.
This reaction is catalyzed by the enzyme ornithine transcarbamylase and occurs in the mitochondrial matrix.
The third step involves the transport of citrulline out of the mitochondria and into the cytoplasm of the liver cell. This is accomplished by a specific transporter protein located in the inner mitochondrial membrane.
In the fourth step, argininosuccinate is formed from citrulline and aspartate. This reaction is catalyzed by the enzyme argininosuccinate synthetase and occurs in the cytoplasm of the liver cell.
Finally, in the fifth and final step of the urea cycle, argininosuccinate is cleaved into arginine and fumarate by the enzyme argininosuccinate lyase.
Arginine is then hydrolyzed by the enzyme arginase to produce urea and ornithine. Urea is excreted by the kidneys, while ornithine is transported back into the mitochondria to begin the cycle again.
Overall, the urea cycle is an essential metabolic pathway that plays a critical role in the elimination of toxic ammonia from the body.
Any disruption in the urea cycle can result in the buildup of ammonia in the body, leading to a condition known as hyperammonemia, which can cause significant neurological damage if left untreated.
MFN 002 Assignment Question Pdf
b) Explain ß-oxidation of fatty acid with diagram
Ans. ß-oxidation is the process by which fatty acids are broken down into acetyl-CoA molecules in the mitochondria of cells. This process occurs in four steps:
- Activation of the fatty acid
- Formation of acetyl-CoA
- Electron transfer and ATP production
- Repetition of the cycle MFN 002 Solved Free Assignment 2023
Here’s a diagram to illustrate the process:
+————————————-+
| |
| Fatty acid (C16:0) |
| |
+——————+——————+
|
v
+——————+——————+
| |
| Fatty acyl-CoA (C16:0) |
| |
+———+———–+—————+
| |
v v
+———–+—-+ +–+————-+
| | | |
| Acetyl-CoA | | Acetyl-CoA |
| | | |
+—————-+ +—————-+
| |
v v
+———+———–+—————+
| |
| Citric Acid Cycle (Krebs Cycle) |
| |
+——————+——————+
|
v
+——————+——————+
| |
| ATP Production via ETC |
| |
+——————+——————+
|
v
+——————+——————+
| |
| Water and CO2 |
| |
+————————————-+
Step 1: Activation of the Fatty Acid
Fatty acids cannot readily cross the inner mitochondrial membrane; therefore, they must first be activated to form acyl-CoA molecules. This reaction requires ATP and is catalyzed by the enzyme fatty acyl-CoA synthetase.
Step 2: Formation of Acetyl-CoA MFN 002 Solved Free Assignment 2023
The activated fatty acid is then transported into the mitochondrial matrix, where it undergoes ß-oxidation. During this process, the fatty acid is repeatedly broken down into two-carbon acetyl-CoA molecules, which can enter the citric acid cycle.
Step 3: involves the hydration of the double bond formed in the previous step. This reaction is catalyzed by the enzyme enoyl-CoA hydratase and adds a molecule of water to the fatty acid molecule.
Step 4: and final step involves the cleavage of the β-ketoacyl-CoA molecule to form acetyl-CoA and a shortened fatty acyl-CoA molecule.
This reaction is catalyzed by the enzyme β-ketothiolase and produces one molecule of acetyl-CoA for each round of ß-oxidation.
The shortened fatty acyl-CoA molecule can then undergo another round of ß-oxidation until it is completely broken down into acetyl-CoA molecules.
Q 5. a) What is the role of pancreas in digestion of food? Explain.
Ans. The pancreas plays a crucial role in the digestion of food. It is a gland located behind the stomach that produces digestive enzymes and hormones that help to break down food in the small intestine. MFN 002 Solved Free Assignment 2023
One of the main functions of the pancreas is to produce digestive enzymes that help to break down carbohydrates, proteins, and fats.
These enzymes are secreted into the small intestine through a duct that connects the pancreas to the duodenum, the first part of the small intestine. The enzymes include:
Amylase – an enzyme that breaks down carbohydrates (starch) into simple sugars.
Proteases – enzymes that break down proteins into smaller peptides and amino acids.
Lipase – an enzyme that breaks down fats (lipids) into fatty acids and glycerol.
The pancreas also produces bicarbonate, a base that neutralizes the acidic chyme (partially digested food mixed with stomach acid) as it enters the small intestine.
This is important because the enzymes produced by the pancreas work best in a slightly alkaline environment. The bicarbonate is secreted into the small intestine along with the digestive enzymes. MFN 002 Solved Free Assignment 2023
In addition to producing digestive enzymes, the pancreas also produces hormones that help to regulate blood sugar levels.
The two main hormones produced by the pancreas are insulin and glucagon. Insulin is secreted in response to high blood sugar levels and helps to lower blood sugar by promoting the uptake of glucose by cells.
Glucagon is secreted in response to low blood sugar levels and helps to raise blood sugar by stimulating the liver to release glucose.
Overall, the pancreas plays a vital role in the digestion of food by producing digestive enzymes that help to break down carbohydrates, proteins, and fats, and by producing bicarbonate to neutralize the acidic chyme.
It also helps to regulate blood sugar levels by producing hormones such as insulin and glucagon. Any disruption in the function of the pancreas can lead to digestive problems and metabolic disorders such as diabetes.
b) How does the HMP pathway differ from glycolysis? Discuss the metabolic significance of HMP pathway in detail.
Ans. The HMP (hexose monophosphate) pathway, also known as the pentose phosphate pathway, is a metabolic pathway that operates parallel to glycolysis.
While glycolysis breaks down glucose into pyruvate, the HMP pathway generates NADPH and ribose-5-phosphate (R5P) from glucose-6-phosphate (G6P).
One of the key differences between the HMP pathway and glycolysis is that the HMP pathway produces NADPH, whereas glycolysis produces ATP.
NADPH is an important reducing agent used in biosynthetic processes, such as the synthesis of fatty acids, cholesterol, and neurotransmitters, and is also involved in detoxification reactions in the liver. MFN 002 Solved Free Assignment 2023
In contrast, ATP is primarily used as an energy source for cellular processes.
Another key difference is that the HMP pathway generates pentose sugars, such as R5P, which are important building blocks for nucleic acids, coenzymes, and other cellular components.
Glycolysis does not produce pentose sugars, and instead generates ATP and pyruvate, which can be further metabolized in the citric acid cycle.
The HMP pathway is particularly important in cells that are actively synthesizing nucleic acids, such as rapidly dividing cells and cells undergoing tissue repair.
In these cells, the demand for NADPH and pentose sugars is high, and the HMP pathway provides a source of these molecules.
The pathway is also important in red blood cells, which lack mitochondria and rely on the HMP pathway for NADPH generation to protect against oxidative stress.
The HMP pathway can also be induced in response to oxidative stress, such as exposure to reactive oxygen species (ROS), which can damage cellular components.
The NADPH generated by the HMP pathway is used to regenerate the antioxidant glutathione, which helps to protect cells from ROS-induced damage.
Q 6. a) Work out the energy (ATP) production when glucose is oxidized in the Glycolysis and citric acid cycle pathways. (Illustrate the cycle and work out the ATP production)
Ans. Glucose is first metabolized through glycolysis to produce pyruvate, which is then further metabolized in the citric acid cycle. Both of these pathways generate ATP through oxidative phosphorylation. MFN 002 Solved Free Assignment 2023
Here is the breakdown of the ATP production in each pathway:
Glycolysis:
👉 2 ATP are consumed in the initial steps of glycolysis to activate glucose and convert it to fructose-1,6-bisphosphate.
👉4 ATP are generated through substrate-level phosphorylation during glycolysis, resulting in a net gain of 2 ATP.
👉 2 NADH molecules are generated during glycolysis, which can be used to generate additional ATP through oxidative phosphorylation in the electron transport chain.
However, the exact number of ATP generated from NADH depends on the specific cell type and conditions.Overall, glycolysis generates a net gain of 2 ATP per glucose molecule. MFN 002 Solved Free Assignment 2023
Citric acid cycle:
👉 2 ATP are generated through substrate-level phosphorylation during the citric acid cycle.
👉 6 NADH and 2 FADH2 molecules are generated during the citric acid cycle, which can be used to generate additional ATP through oxidative phosphorylation in the electron transport chain.
Again, the exact number of ATP generated from NADH and FADH2 depends on the specific cell type and conditions.
Overall, the citric acid cycle generates a total of 2 ATP, 6 NADH, and 2 FADH2 per glucose molecule. MFN 002 Solved Free Assignment 2023
The NADH and FADH2 molecules generated from both glycolysis and the citric acid cycle are then used in the electron transport chain to generate ATP through oxidative phosphorylation.
The exact amount of ATP generated from each NADH and FADH2 molecule depends on the specific cell type and conditions, but it is generally estimated that each NADH molecule generates 2.5 ATP, while each FADH2 molecule generates 1.5 ATP.
b) What are free radicals and antioxidants? Give examples of each.
Ans. Free radicals are unstable molecules that have an unpaired electron in their outer shell.
This unpaired electron makes them highly reactive and they can cause damage to other molecules in the body, such as lipids, proteins, and DNA.
Free radicals can be generated as by-products of normal cellular metabolism, but they can also be produced by environmental factors such as pollution, radiation, and smoking. MFN 002 Solved Free Assignment 2023
Antioxidants are molecules that neutralize free radicals by donating an electron to them, thus preventing them from causing damage to other molecules in the body.
Antioxidants can be produced by the body, but they are also found in a variety of foods, particularly fruits, vegetables, and nuts.
Examples of free radicals include:
Reactive oxygen species (ROS), such as superoxide, hydrogen peroxide, and hydroxyl radicals, which are produced during normal cellular metabolism as well as in response to environmental factors.
Nitric oxide (NO), which is involved in many physiological processes, but can also react with other molecules to form harmful free radicals.
Examples of antioxidants include:
Vitamin C, which is found in many fruits and vegetables and acts as a scavenger of free radicals.
Vitamin E, which is found in nuts, seeds, and vegetable oils, and protects cell membranes from oxidative damage. MFN 002 Solved Free Assignment 2023
Beta-carotene, which is found in many fruits and vegetables, and is a precursor to vitamin A. It acts as an antioxidant in the body.
Glutathione, which is produced by the body and acts as a major antioxidant, particularly in the liver.
Flavonoids, which are plant compounds found in many fruits and vegetables, and have antioxidant properties.
Consuming a diet rich in antioxidants can help to prevent oxidative damage to cells and tissues, and may reduce the risk of chronic diseases such as cancer, heart disease, and neurodegenerative disorders.
Q 7. a) Explain the following:
(i) Role of Vitamin A in the visual cycle.
Ans. (i) Vitamin A is essential for vision because it is a component of rhodopsin, a protein found in the rod cells of the retina that is responsible for vision in low light conditions. MFN 002 Solved Free Assignment 2023
Rhodopsin contains a molecule called retinal, which is derived from vitamin A. When light enters the eye, it is absorbed by the retinal molecule, causing a change in its shape that triggers a series of chemical reactions that ultimately result in the transmission of a nerve impulse to the brain.
Without vitamin A, the production of rhodopsin is impaired, leading to night blindness and other vision problems.
(ii) Role of Vitamin D in the intestinal absorption of calcium in our body.
Ans (ii) Vitamin D plays a crucial role in the absorption of calcium from the intestine. When vitamin D is present in the body, it stimulates the production of a calcium-binding protein called calbindin, which is found in the cells lining the intestine.
Calbindin helps to transport calcium across the intestinal wall and into the bloodstream, where it can be used by the body for a variety of functions, such as building and maintaining strong bones. MFN 002 Solved Free Assignment 2023
Without vitamin D, the absorption of calcium from the diet is severely limited, leading to conditions such as rickets in children and osteomalacia in adults.
b) What is inborn error of metabolism? Enlist the disease related to carbohydratemetabolism and explain any one.
Ans. An inborn error of metabolism is a genetic disorder that affects the body’s ability to process certain nutrients or chemicals.
These disorders are usually caused by mutations in genes that code for enzymes involved in metabolic pathways. Some examples of inborn errors of metabolism related to carbohydrate metabolism include:
Phenylketonuria (PKU): This is a disorder in which the body is unable to break down the amino acid phenylalanine, leading to a buildup of toxic byproducts in the blood and brain. It is caused by a deficiency in the enzyme phenylalanine hydroxylase.
Galactosemia: This is a disorder in which the body is unable to metabolize the sugar galactose, which is found in milk and other dairy products.
It is caused by a deficiency in one of three enzymes involved in the metabolism of galactose. MFN 002 Solved Free Assignment 2023
Glycogen storage disease: This is a group of disorders in which the body is unable to store or break down glycogen, a complex sugar that is used as a source of energy.
There are several different types of glycogen storage disease, each caused by a deficiency in a different enzyme involved in glycogen metabolism.
One example of a carbohydrate metabolism disorder is PKU. PKU is caused by a deficiency in the enzyme phenylalanine hydroxylase, which is responsible for converting phenylalanine to another amino acid called tyrosine.
Without this enzyme, phenylalanine builds up in the blood and brain, leading to intellectual disability, seizures, and other neurological problems.
Treatment involves a strict low-phenylalanine diet, which can prevent or minimize the symptoms of the disorder.
Q 8. a) Describe the biochemical role of the hormones produced by the following glands in our body:
(i) Adrenal Medulla MFN 002 Solved Free Assignment 2023
Ans. a)(i) The adrenal medulla produces the hormones adrenaline and noradrenaline, which are involved in the body’s response to stress.
These hormones increase heart rate, blood pressure, and respiration, and also cause the liver to release glucose into the bloodstream, providing energy for the body to deal with the stressor.
(ii) Anterior Pituitary
(ii) The anterior pituitary produces a variety of hormones that regulate growth, metabolism, and reproduction. MFN 002 Solved Free Assignment 2023
For example, it produces growth hormone, which stimulates the growth and development of bones, muscles, and other tissues.
It also produces thyroid-stimulating hormone, which regulates the production of thyroid hormones that are involved in metabolism.
b)Differentiate between the following disease conditions:
i)Maple Syrup Urine Disease and Alcaptonuria
ii) Thalassemia and Sickle cell anaemia
Ans.b)
(i) Maple syrup urine disease and alkaptonuria are both inherited metabolic disorders.
Maple syrup urine disease is caused by a deficiency in one of three enzymes involved in the breakdown of branched-chain amino acids, leading to a buildup of toxic byproducts in the blood and urine.
This can cause a variety of symptoms, including poor feeding, vomiting, lethargy, and neurological problems. MFN 002 Solved Free Assignment 2023
Alkaptonuria is caused by a deficiency in an enzyme involved in the breakdown of a type of amino acid called tyrosine, leading to a buildup of a compound called homogentisic acid in the blood and urine.
This can cause joint pain, arthritis, and discoloration of the skin and eyes.
(ii) Thalassemia and sickle cell anemia are both inherited blood disorders. Thalassemia is caused by a deficiency in the production of hemoglobin, the protein in red blood cells that carries oxygen.
This can lead to anemia, fatigue, and other symptoms. Sickle cell anemia is caused by a mutation in the gene that codes for hemoglobin, leading to the production of abnormal hemoglobin molecules that can cause the red blood cells to become rigid and sickle-shaped. MFN 002 Solved Free Assignment 2023
This can cause a variety of symptoms, including anemia, pain, and organ damage. While thalassemia is typically treated with blood transfusions and other supportive measures, sickle cell anemia can be managed with a variety of treatments, including medication, blood transfusions, and bone marrow transplants.
Section B –
Q 1. Explain the following in 2-3 sentences. Also give the structure wherever possible.
a. Amylopectin
b. Galactosemia
c. Dehydrogenation
d. Porphyrins
e. Apolipoproteins
f. Thromboxanes
g. Anaplerotic reaction
h. Isozymes
i. Mutarotation
j. Zwitterion
Ans. a. Amylopectin is a branched-chain polymer of glucose molecules and a major component of starch in plants. Its structure consists of alpha-1,4-linked glucose chains with alpha-1,6-linked branches. MFN 002 Solved Free Assignment 2023
b. Galactosemia is an inherited disorder that affects the body’s ability to metabolize galactose, a sugar found in milk and other dairy products. It is caused by a deficiency in one of three enzymes needed to break down galactose.
c. Dehydrogenation is a chemical reaction that involves the removal of hydrogen atoms from a molecule. This often results in the formation of a double bond between two carbon atoms.
d. Porphyrins are organic compounds that contain four pyrrole rings connected by methylene bridges. They are important components of heme, a molecule found in hemoglobin and other proteins involved in oxygen transport.
e. Apolipoproteins are proteins that bind to lipids to form lipoproteins, which transport lipids through the bloodstream. They play a critical role in lipid metabolism and cardiovascular disease. MFN 002 Solved Free Assignment 2023
f. Thromboxanes are a family of eicosanoids that are involved in platelet aggregation and blood clotting. They are synthesized from arachidonic acid and act locally at the site of injury to promote clotting.
g. Anaplerotic reactions are metabolic reactions that replenish depleted metabolic intermediates in a pathway. They are important for maintaining metabolic homeostasis and energy balance.
h. Isozymes are different forms of an enzyme that catalyze the same reaction but have different amino acid sequences and physical properties. They often have different tissue distributions and play different roles in cellular metabolism.
i. Mutarotation is the spontaneous interconversion of a pure anomeric form of a sugar between its alpha and beta configurations. This process occurs in solution due to the open-chain form of the sugar. MFN 002 Solved Free Assignment 2023
j. A zwitterion is a molecule that contains both a positively charged and a negatively charged functional group, resulting in a net charge of zero.
Amino acids are an example of zwitterions, with a positively charged amino group and a negatively charged carboxyl group.
Q 2. Name the defective enzyme in the following diseases:
a) Phenylketonuria
b) Tyrosinemia Type I
c) Niemann-Pick disease
d) Hereditary Lactose intolerance
e) Pentosuria
Ans. a) Phenylketonuria – Phenylalanine hydroxylase
b) Tyrosinemia Type I – Fumarylacetoacetate hydrolase
c) Niemann-Pick disease – Sphingomyelinase
d) Hereditary Lactose intolerance – Lactase
e) Pentosuria – L-xylulokinase MFN 002 Solved Free Assignment 2023
Q 3 Match the following:
| I Porphyrin | A. 3-hydroxybutyrate |
| II Ketone bodies | B. Heme |
| III Lipoprotein | C. Glutathione peroxidase |
| IV Lactate | D. HDL |
| V Selenium | E. Cori Cycle |
Ans.I – B Heme
II – A 3-hydroxybutyrate
III – D HDL
IV – E Cori Cycle
V – C Glutathione peroxidase
IGNOU MFN 001 Solved Free Assignment 2023