Water soluble vitamins from P.88 to P.98

What is another name for Vitamin C?

Vitamin C is also known as "L-ascorbic acid" and "Antiscorbutic vitamin."

Why do humans need to obtain vitamin C from their diet?

Humans lack gulconate oxidase, which prevents them from synthesizing vitamin C in their bodies. Therefore, they need to obtain it from their diet.

What is the result of the oxidation of vitamin C?

The oxidation of vitamin C results in the formation of oxalate. In fact, L-ascorbic acid metabolism contributes to about half of the urinary oxalate.

How is vitamin C affected by cooking, light, and storing?

Vitamin C is destroyed by direct cooking, exposure to light, and prolonged storage.

What are some sources of vitamin C?

Sources of vitamin C include citrus fruits (e.g., lemon, orange, guava) and green leafy vegetables.

What is the main function of vitamin C as a reducing agent?

Vitamin C acts as a potent reducing agent and functions as a hydrogen carrier.

What is the role of collagen formation in the body?

Collagen formation is essential for wound healing, providing strength to capillary walls, bone matrix formation, and synthesis of catecholamines (adrenaline and noradrenaline) in the adrenal medulla, as well as synthesis of adrenal cortical hormones like cortisol.

What is the significance of catecholamines?

Catecholamines, including adrenaline and noradrenaline, play important roles in the body's stress response and regulation of various physiological processes.

What is the function of carnitine?

Carnitine is a protein present in muscles that stimulates fatty acid oxidation in the mitochondria, contributing to energy production from fats.

What is the main function of vitamin C as a reducing agent?

Vitamin C acts as a potent reducing agent and functions as a hydrogen carrier.

What is the role of collagen formation in the body?

Collagen formation is essential for wound healing, providing strength to capillary walls, bone matrix formation, and synthesis of catecholamines (adrenaline and noradrenaline) in the adrenal medulla, as well as synthesis of adrenal cortical hormones like cortisol.

What is the significance of catecholamines?

Catecholamines, including adrenaline and noradrenaline, play important roles in the body's stress response and regulation of various physiological processes.

What is the function of carnitine?

Carnitine is a protein present in muscles that stimulates fatty acid oxidation in the mitochondria, contributing to energy production from fats.

What does vitamin C help convert cholesterol into?

Vitamin C is needed for the conversion of cholesterol into bile acids.

What does vitamin C aid in converting folic acid into?

Vitamin C is needed for the conversion of folic acid into the physiologically active tetrahydrofolate (FH4).

How does vitamin C contribute to iron absorption?

Vitamin C aids in iron absorption by reducing ferric iron into absorbable ferrous Fe.

What is the role of vitamin C in tyrosine metabolism?

Vitamin C is needed for tyrosine metabolism.

In what types of reactions does vitamin C act as a hydrogen carrier?

Vitamin C acts as a hydrogen carrier in oxidation-reduction reactions.

Does vitamin C have any anticancer effects?

Yes, vitamin C is known to have anticancer effects.

What is the antioxidant function of vitamin C?

Vitamin C acts as an antioxidant.

What effect does vitamin C have on the immune system?

Vitamin C has an immuno-stimulant effect, including stimulating histamine release in stress conditions and relieving symptoms of the common cold due to its role in normal leucocyte function.

What happens when there is a deficiency of vitamin C?

A deficiency of vitamin C leads to scurvy if the vitamin C stores are depleted. This deficiency can be caused by chronic diseases like cancer, contraceptive pill use, cigarette smoking, and alcoholism.

What are the manifestations of scurvy?

Manifestations of scurvy include: - Easy bruising and hemorrhage under the skin due to increased capillary fragility. - Swollen, tender, and easily bleeding gums. - Loose teeth that may fall. - Poor wound healing and osteoporosis (due to collagen defect). - Anemia (due to hemorrhage, iron malabsorption, or folic acid defect). - Decreased immune competence or immune power.

Vitamins act as antioxidants include

Vitamin A. Vitamin E. Vitamin C.

Vitamins involved in bone metabolism include

1\. Vitamin D.

2\. Vitamin C.

3\. Vitamin K.

4\. Vitamin A.

What are the common sources of Vitamin B complex?

Vitamin B complex sources include: - Plant sources: grains, yeast, green leafy vegetables. - Animal sources: Liver, kidney, milk, fish, egg yolk. - Intestinal flora: Intestinal flora is the most important source of Vitamin B complex in humans.

Sulfur containing vitamins

A. Thiamine "vitamin Bl, anti beri beri " B. Biotin. C. Pantothenic acid "COASH". D. Lipoic acid.

What is the active form of Thiamine?

The active form of Thiamine is thiamine pyrophosphate (TPP).

What are the functions of Thiamine?

Thiamine has several functions, including: - Acting as a coenzyme for decarboxylation reactions of a-ketoacids, such as pyruvate and a-ketoglutarate. - Serving as a coenzyme for transketolase in the HMP pathway in red blood cells (R.B.Cs), with its activation being an index of thiamine nutritional status. - Playing a role in the growth of children and infants. - Increasing the activity of acetylcholine at nerve endings by inhibiting acetylcholine esterase, which enhances the conduction of nerve impulses.

What are the causes of thiamine deficiency?

- Dietary restriction (carbohydrate rich- low thiamine diet) - Thiamine needed for carbohydrate metabolism - Consumption of raw fishes containing thiaminase (heat labile protein) - Chronic fevers - Alcoholism (inhibits thiamine absorption and decreases appetite) - Long-term renal dialysis or use of antacids (alkalinity destroys thiamine)

Why is thiamine important for the body?

Thiamine is needed for carbohydrate metabolism.

How can alcohol contribute to thiamine deficiency?

Alcohol inhibits thiamine absorption and decreases appetite.

What is thiaminase and how does it affect thiamine?

Thiaminase is a heat labile protein found in raw fishes, and it inactivates thiamine.

What factors can lead to thiamine deficiency in individuals?

- Dietary restrictions - Consumption of raw fishes containing thiaminase - Chronic fevers - Alcoholism - Long-term renal dialysis or use of antacids

Beri beri has two forms. What are they?

- Dry beri beri - Wet beri beri

What are the manifestations of dry beri beri?

Dry beri beri affects the nervous system and is manifested by: - Polyneuritis - Hyperesthesia - Weight loss - Muscle wasting

What are the manifestations of wet beri beri?

Wet beri beri affects the cardiovascular system and is manifested by: - Congestive heart failure

What does extreme thiamine deficiency lead to?

Extreme deficiency can lead to: - Wernicke's disease, manifested by ocular disturbances & ataxia. - Korsakoff's disease, manifested by poor memory with impaired learning ability.

What is the function of Lipoic acid?

Lipoic acid functions as a coenzyme for the oxidative decarboxylation of a-keto acids.

What is the function of Biotin (Vitamin H)?

It is a coenzyme for carboxylase enzyme that catalyzes the carboxylation "C02 fixation" reaction.

Name one carboxylation reaction catalyzed by Biotin.

Pyruvate carboxylation into oxaloacetate catalyzed by pyruvate carboxylase.

Which enzyme catalyzes the carboxylation of propionyl COA into succinyl COA with the help of Biotin?

Propionyl COA carboxylation into succinyl COA catalyzed by propionyl COA carboxylase.

What is the role of Biotin in purine synthesis?

Fixation of C02 to form C6 of purines.

Besides its role as a coenzyme, what other function does Biotin have?

Regulation of cell cycle.

What can cause a deficiency of Biotin?

Deficiency of Biotin can result from various factors, including genetic conditions, consumption of raw eggs, sulfa antibiotics (which inhibit intestinal bacteria), and certain medical conditions.

What is the heat-labile protein found in raw eggs that can bind to Biotin and inhibit its absorption?

Raw eggs contain a heat-labile protein called avidin, which can bind to Biotin and hinder its absorption.

What are some clinical manifestations of Biotin deficiency?

Biotin deficiency can lead to several clinical symptoms, including dermatitis, depression, decreased immunity in children with growth retardation, hair loss, hallucinations, and pallor.

What is the active sulfur-containing form of Pantothenic acid in tissues?

The active sulfur-containing form of Pantothenic acid in tissues is coenzyme A (CoASH).

What are the functions of CoASH (coenzyme A)?

CoASH acts as a carrier for various processes, including: 1. Forming acetyl CoA, which is essential for ketogenesis. 2. Assisting in lipogenesis, which is the synthesis of fatty acids. 3. Participating in the formation of steroids. 4. Undergoing oxidation in the Krebs cycle. 5. Entering acetylation reactions, including histone acetylation, formation of acetylcholine, polysaccharides, and detoxification reactions. 6. Serving as a carrier for fatty acids, forming acyl CoA, succinic acid, forming succinyl CoA, and other carboxylic acids.

How does Pantothenic acid contribute to fatty acid synthesis?

Pantothenic acid is involved in the structure of the fatty acid synthase complex, enabling the extra-mitochondrial pathway of fatty acid synthesis.

What is the primary role of coenzyme A (CoASH) in the body?

Coenzyme A (CoASH) serves as a carrier for various biochemical processes.

Name two important functions of acetyl CoA, formed with the help of Pantothenic acid.

Acetyl CoA, derived from Pantothenic acid, plays a crucial role in ketogenesis and lipogenesis (fatty acid synthesis).

What is the significance of CoASH in the formation of steroids?

CoASH is involved in the formation of steroids, which are essential for various physiological functions in the body.

In which metabolic pathway does CoASH undergo oxidation?

CoASH undergoes oxidation in the Krebs cycle, also known as the citric acid cycle or the TCA cycle.

Give an example of an acetylation reaction where CoASH is involved.

CoASH participates in acetylation reactions such as histone acetylation, the formation of acetylcholine, the synthesis of polysaccharides, and detoxification reactions.

What are some of the carboxylic acids for which CoASH acts as a carrier?

CoASH serves as a carrier for fatty acids (forming acyl CoA), succinic acid (forming succinyl CoA), and other carboxylic acids.

How does Pantothenic acid contribute to fatty acid synthesis, and where does this synthesis occur?

Pantothenic acid is involved in the structure of the fatty acid synthase complex, enabling the extra-mitochondrial pathway of fatty acid synthesis.

What are the active forms of Riboflavin?

The active forms of Riboflavin are FMN (Flavin mononucleotide) and FAD (Flavin Adenine dinucleotide).

What are the main functions of FMN and FAD, the active forms of Riboflavin?

FMN and FAD serve as hydrogen carriers in oxidation-reduction reactions, which are important for various metabolic processes, including: 1. Carbohydrate metabolism. 2. Lipid metabolism. 3. Amino acids oxidation. 4. Sterol biosynthesis. 5. Metabolism of purine and pyrimidine.

What are FMN and FAD, and how are they related to Riboflavin?

FMN (Flavin mononucleotide) and FAD (Flavin Adenine dinucleotide) are the active forms of Riboflavin, meaning they are derived from Riboflavin and play important roles in various biochemical reactions.

How does Riboflavin contribute to carbohydrate metabolism?

Riboflavin, through its active forms FMN and FAD, participates in oxidation-reduction reactions crucial for carbohydrate metabolism.

What role does Riboflavin play in lipid metabolism?

Riboflavin, via FMN and FAD, is involved in oxidation-reduction reactions essential for lipid metabolism.

Give an example of a metabolic process where Riboflavin is essential for amino acids oxidation.

Riboflavin is essential for amino acids oxidation, which is a fundamental process in the breakdown of amino acids for energy production.

In what significant biochemical pathway is Riboflavin important for sterol biosynthesis?

Riboflavin plays a crucial role in sterol biosynthesis, a pathway involved in the production of sterols, such as cholesterol.

How does Riboflavin contribute to the metabolism of purine and pyrimidine?

Riboflavin, in the form of FMN and FAD, is involved in oxidation-reduction reactions that are part of the metabolism of purine and pyrimidine, which are essential components of nucleic acids.

What are some clinical signs of Riboflavin deficiency?

Riboflavin deficiency can lead to several clinical manifestations, including: 1. Red lips & glossitis. 2. Ocular manifestations, such as photophobia and vascularization of the cornea. 3. Seborrheic dermatitis. 4. Decreased protein synthesis.

What is another name for Niacin?

Niacin is also known as Nicotinic acid and is referred to as Pellagra preventing factor (PPF).

What coenzymes does Niacin in the form of nicotinamide participate in the formation of?

Niacin in the form of nicotinamide is involved in the formation of the following coenzymes: 1. NAD (coenzyme I): Nicotinamide adenine dinucleotide. 2. NADP+ (coenzyme II): Nicotinamide adenine dinucleotide phosphate. 3. NMN (coenzyme III): Nicotinamide mononucleotide.

What are the sources of Niacin, and how is it synthesized endogenously?

Niacin can be obtained from dietary sources as previously mentioned, but it is also endogenously synthesized from tryptophan. The synthesis of niacin from tryptophan requires vitamin B2 and vitamin B6. Approximately 60 grams of tryptophan can synthesize 1 gram of niacin.

What is the effect of Nicotinic acid on the central nervous system (CNS)?

Nicotinic acid acts as a CNS stimulant.

How does Nicotinic acid (niacin) contribute to the formation of NMN (coenzyme III)?

Nicotinic acid in the form of nicotinamide is involved in the formation of NMN (coenzyme III), which serves as a coenzyme for taurine synthesis and is a component in the formation of bile salts.

What are the roles of NAD (coenzyme I) and NADP+ (coenzyme II) in metabolism?

Both NAD and NADP+ function as hydrogen carriers in oxidation-reduction reactions that are essential for carbohydrate, lipid, and protein metabolism.

What is the condition caused by Niacin deficiency?

Niacin deficiency leads to a condition known as Pellagra.

What are the primary causes of Niacin deficiency?

Niacin deficiency can result from the following causes: 1. Decreased intake, especially in individuals who rely on maize (corn protein) containing zein, which is deficient in tryptophan. 2. Deficiency of vitamin B2, B6, and tryptophan, which are precursors required for niacin synthesis. 3. Hartnup disease, characterized by defective renal and intestinal carrier-mediated transport of neutral amino acids, primarily affecting tryptophan absorption, even with an adequate intake.

What are the clinical manifestations of Niacin deficiency?

Niacin deficiency can lead to the "3D's," which are: 1. Diarrhea 2. Dementia 3. Dermatitis

Where on the skin do dermatitis symptoms typically appear in Niacin deficiency?

Dermatitis symptoms in Niacin deficiency often appear in sun-exposed areas of the skin.

What are the three forms of Vitamin B6, and how are they activated?

The three forms of Vitamin B6 are pyridoxine phosphate, pyridoxal phosphate (PLP), and pyridoxamine phosphate. All of them are activated in their phosphorylated form.

What is the role of Vitamin B6 in terminating the action of steroid hormones?

Vitamin B6, when deficient, leads to increased sensitivity to low concentrations of steroid hormones. It plays a crucial role in removing the hormone-receptor-complex from DNA binding, affecting hormone-dependent cancers such as breast, uterine, and prostate cancer.

Why is PLP (pyridoxal phosphate) essential for the synthesis of niacin from tryptophan?

PLP is essential for the conversion of tryptophan into niacin, a process that requires Vitamin B6.

How does PLP (pyridoxal phosphate) contribute to hemoglobin synthesis?

PLP is an essential coenzyme in the synthesis of hemoglobin, a crucial component of red blood cells.

What is the role of PLP in sphingosine synthesis, and why is sphingosine important?

PLP is a coenzyme for sphingosine synthesis, which is necessary for the formation of sphingolipids, crucial for myelin formation.

How does PLP participate in glycogen metabolism?

PLP serves as a coenzyme for glycogen phosphorylase, which is required for the breakdown of glycogen.

In what processes does PLP play a significant role in amino acids absorption and metabolism?

PLP plays a crucial role in amino acids absorption, as well as amino acids metabolism through transamination reactions, non-oxidative deamination, and decarboxylation reactions, such as the conversion of glutamate to GABA, a neurotransmitter.

What are the primary causes of Vitamin B6 deficiency?

Vitamin B6 deficiency can result from various causes, including: 1. Decreased intake of Vitamin B6. 2. Increased demand, such as during pregnancy. 3. Interaction with medications like Isoniazid (I.N.H), which binds Vitamin B6 and inactivates it.

What are the clinical manifestations of Vitamin B6 deficiency?

Vitamin B6 deficiency can lead to several clinical manifestations, including: 1. Disturbance of amino acid metabolism, resulting in growth and mental retardation. 2. Decreased production of GABA in the brain, leading to mental retardation and convulsions in young infants. 3. Anemia due to a decrease in hemoglobin synthesis. 4. Demyelination of peripheral nerves due to sphingosine defect. 5. Pellagra, which occurs due to a defect in niacin synthesis. 6. Nausea and vomiting in early pregnancy, explained by the depletion of Vitamin B6 in amino acid metabolism required for the synthesis of new proteins in the embryo.

How does Vitamin B6 deficiency affect amino acid metabolism and growth?

Vitamin B6 deficiency can disrupt amino acid metabolism, leading to disturbances in growth and mental retardation.

What neurological consequences can occur due to a decrease in GABA production in the brain caused by Vitamin B6 deficiency?

A decrease in GABA production in the brain due to Vitamin B6 deficiency can result in mental retardation and convulsions, particularly in young infants.

What is the connection between Vitamin B6 deficiency and anemia?

Vitamin B6 deficiency can lead to anemia due to a decrease in hemoglobin synthesis.

What happens to peripheral nerves in Vitamin B6 deficiency, and why does it lead to demyelination?

Vitamin B6 deficiency can result in demyelination of peripheral nerves due to a sphingosine defect.

How does Vitamin B6 deficiency contribute to the development of Pellagra?

Vitamin B6 deficiency can cause Pellagra due to a defect in niacin synthesis.

What is the explanation for nausea and vomiting in early pregnancy in relation to Vitamin B6 deficiency?

Nausea and vomiting in early pregnancy may be explained by the depletion of Vitamin B6, which is essential for amino acid metabolism required for the synthesis of new proteins in the embryo.

What is the only absorbable form of folate?

The only absorbable form of folate is pteroyl monoglutamate.

How do medications like Methotrexate, anti-malarial drugs, and antibacterials like trimethoprim affect Folic acid metabolism?

Medications like Methotrexate, anti-malarial drugs, and antibacterials such as trimethoprim are structurally similar to dihydrofolate reductase (DHFR) and competitively inhibit it. This inhibition prevents the formation of FH4 (tetrahydrofolate), which is essential for DNA synthesis, thereby halting the S-phase of the cell cycle, particularly in rapidly dividing cells like bacteria, other organisms, or cancer cells.

How does Folate therapy during pregnancy benefit fetal development?

Folate therapy during pregnancy reduces the risk of neural tube defects in the developing fetus.

What role does Folate play in reducing the risk of high blood homocysteine levels, and why is this important?

Folate helps decrease the risk of high blood homocysteine levels, which is a significant risk factor for the development of atherosclerosis, hypertension, and thrombosis.

How can Folate contribute to reducing the risk of certain cancers, such as colorectal cancer?

Folate intake is associated with a reduced risk of developing certain cancers, including colorectal cancer.

What is the role of FH4 (tetrahydrofolate) in carrying one-carbon fragments or units, and why is this important?

FH4 serves as a carrier for one-carbon fragments or units, including formimino and methyl groups. This role is crucial for nucleic acid synthesis and hemopoiesis.

What are the potential causes of Folic acid deficiency?

Folic acid deficiency can result from various causes, including: 1. Decreased intake of folate. 2. Increased demand, as in pregnancy and lactation. 3. Impaired metabolism or absorption of folate. 4. Use of anticonvulsant or contraceptive pills, which can inhibit folate absorption. 5. Alcoholism. 6. Vitamin B12 deficiency, leading to functional folate deficiency (methyl or folate trap) where most of the carbons in the FH4 pool are trapped in the methyl FH4 form (the most stable form).

Manifestations of folate deficiency

What are the manifestations of folate deficiency?

Pancytopenia, impaired growth, accumulation of FIGIu

What are the specific manifestations of folate deficiency?