Vitamin Water Soluble - 11 2023 PDF

BIOCHEMISTRY HUMAN METABOLISM Dr. Ahmed M Issa 1 vitamin water soluble - 11 2023 ،‫تشرين األول‬  Water- soluble vitamins This group of vitamins consist of vitamin B group and vitamin C :The B vitamins are B1 (thiamine)...

BIOCHEMISTRY HUMAN METABOLISM Dr. Ahmed M Issa 1 vitamin water soluble - 11 2023 ،‫تشرين األول‬  Water- soluble vitamins This group of vitamins consist of vitamin B group and vitamin C :The B vitamins are B1 (thiamine) B2 (riboflavin) B3 (niacin) B5 (pantothenic acid) B6 (pyridoxine) B7 (biotin) B9 (Folate) B12(cobalamin) PAGE 1 2 vitamin water soluble - 11 2023 ،‫تشرين األول‬  These vitamins help the process our body Vit B1 is needed in proper nerve function uses to get or make energy from the and the formation of DNA and RNA. food. They also help form red blood cells. Vitamin B1 (thiamine) contains two B vitamins exist in proteins such as fish, heterocyclic rings—a pyrimidine ring and a poultry, meat, eggs, and dairy products. thiazole ring which are joined by a Leafy green vegetables, beans, peas and methylene group. The active form of.many cereals have some B vitamins vitamin B1 is thiamine diphosphate (TPP), which contributes as a coenzyme to the transfer of hydroxyl-alkyl residues (active Thiamine. Vit B1 aldehyde groups). The most important reactions of this type are oxidative decarboxylation of 2-oxoacids and the transketolase reaction in the pentose.phosphate pathway PAGE 3 PAGE 2 3 vitamin water soluble - 11 2023 ،‫تشرين األول‬  Thiamin is a coenzyme for many cellular enzymes like pyruvate dehydrogenase, α- ketoglutarate dehydrogenase, transketolase,and others. Consequently, this coenzyme is needed in biochemical pathways like glycolytic pathway , TCA cycle, hexose monophosphate shunt and the metabolism of valine, isoleucine and leucine. Vitamin B1 deficiency leads to beriberi, a disease with symptoms that include neurological disturbances, cardiac insufficiency, and muscular atrophy. Most common causes of vit B1 deficiency are alcoholism (alcohol interferes with the absorption) and PAGE 5 PAGE 4.psychosis 4 vitamin water soluble - 11 2023 ،‫تشرين األول‬  :Riboflavin. Vit B2 Vit B2 is needed in the release of ATP Vitamin B2 Riboflavin (from the Latin flavus, yellow) serves in the metabolism as a component of the redox coenzymes flavin mononucleotide (FMN) and flavin adenine dinucleotide As prosthetic groups, FMN and FAD are cofactors for various oxidoreductases 7 PAGE 7 PAGE 6 PAGE 5 vitamin water soluble - 11 2023 ،‫تشرين األول‬  Its deficiency is associated with corneal neovascularization, cheilosis and stomatitis (cracking or scaling of lip borders and corners of the mouth) , magenta -colored.tongue PAGE 9 PAGE 8 6 vitamin water soluble - 11 2023 ،‫تشرين األول‬  :Niacin. Vit B3 The animal organism is able to. Vit B3 is essential for steroid and convert tryptophan into RBC formation Nicotinate and nicotinate, but only with a poor nicotinamide, together referred to yield. Vitamin deficiency as “niacin,” are required for therefore only occurs when biosynthesis of the coenzymes nicotinate, nicotinamide, and nicotinamide adenine dinucleotide tryptophan are all simultaneously (NAD+) and nicotinamide adenine dinucleotide phosphate (NADP+). are lacking in the diet. It These both serve in energy and manifests in the form of nutrient metabolism as carriers of (pellagra). Pellagra is the hydride ions ""disease of the four D's.Diarrhea Dermatitis: inflammation of. the skin Dementia: Mental disorientation, PAGE 11 PAGE10.delusions and depression 7.Death vitamin water soluble - 11 2023 ،‫تشرين األول‬  Niacin (nicotinic acid, vitamin B3) was considered a promising candidate to prevent cardiovascular disease because it is known to lower cholesterol in the blood, which is one of the main risk factors. Therefore, long term therapy with niacin was assumed to PAGE 13 PAGE12 reduce the risk of heart attack,.and stroke 8 vitamin water soluble - 11 2023 ،‫تشرين األول‬ ‐  :Pantothenic acid. Vit B5 Pantothenic acid, in its function as a cofactor for CoA, is necessary for the synthesis of many compounds Pantothenic acid is an acid amide including fatty acids, cholesterol, consisting of β-alanine and pantoic acid. It steroid hormones, molecules is a precursor of coenzyme A, which is containing isoprenoid units (e.g., vitamins A and D), δ-aminolevulinic required for activation of acyl residues in acid, and some neurotransmitters and the lipid metabolism.amino acids Symptoms of deficiency are similar to other vitamin B deficiencies. There is impaired energy production, due to low CoA levels, which could cause symptoms of irritability , fatigue, and apathy PAGE 15 PAGE 14 9 vitamin water soluble - 11 2023 ،‫تشرين األول‬  Acyl carrier protein (ACP) also contains pantothenic acid as part of its prosthetic group. Due to the widespread availability of pantothenic acid in food (Greek pantothen = “from everywhere”), deficiency diseases are rare. Antothenic acid (vitamin B5) supplementation has been shown to significantly reduce acne within just 12.weeks of supplementation PAGE 17 PAGE 16 10 vitamin water soluble - 11 2023 ،‫تشرين األول‬  The active form of vitamin B6, : Pyridoxine. Vit B6 pyridoxal phosphate, is the most important coenzyme in the amino acid metabolism. Pyridoxine, pyridoxamine, and pyridoxal are rapidly absorbed from food and oral drugs by mucosal cells of the small intestine Vitamin B6 consists of three substituted pyridines— pyridoxal, pyridoxol, and pyridoxamine. The illustration shows the structure of pyridoxal, which carries an aldehyde group (–CHO) at C-4. Pyridoxol is the Almost all conversion reactions corresponding alcohol (–CH2OH), and.pyridoxamine the amine (–CH2NH2) involving amino acids require PAGE 19 PAGE 18 pyridoxal phosphate, including 11 vitamin water soluble - 11 2023 ،‫تشرين األول‬  Transaminations by aminotransferases like-1.AST (GOT) and ALT (GPT) Decarboxylations as in δ- amino levulinate-2 synthesis and decarboxylation of amino acids.to form amine neurotransmitters Dehydrogenations-3 Glycogen phosphorylase, the enzyme for glycogen degradation, also contains pyridoxal phosphate as a cofactor. Vitamin B6 deficiency is rare. It may be due to poor renal function, autoimmune diseases, increased alcohol intake and isoniazid therapy. It is usually concomitant with sideroblastic anemia. Vitamin B6 deficiency can be observed clinically as seborrheic dermatitis, microcytic anemia, dental decay, glossitis, PAGE 21 epileptiform convulsions, peripheral neuropathy, depression, confusion, PAGE 20.and weakened immune function 12 vitamin water soluble - 11 2023 ،‫تشرين األول‬  CO2 binds, using ATP, to one of the :Biotin -Vit B7 two N atoms of biotin, from which it is transferred to the acceptor.Biotin Food sources for this vitamin include liver, egg yolk, peanut butter, and soy binds with high affinity and flour. It is also synthesized by the specificity to avidin, a protein found intestinal flora. In the body, biotin is covalently attached via a lysine side in egg white. Since boiling denatures chain to enzymes that catalyze avidin, biotin deficiency only occurs carboxylation reactions. Biotin- dependent carboxylases include when egg whites are eaten raw. This pyruvate carboxylase and acetyl- CoA vitamin is necessary for pathways. carboxylase like gluconeogenesis and fatty acid synthesis. Excessive consumption of raw egg lead to biotin deficiency which cause alopecia (hair loss), PAGE 23 PAGE 22.bowel inflammation and muscle pain 13 vitamin water soluble - 11 2023 ،‫تشرين األول‬  PAGE 25 PAGE 24 14 vitamin water soluble - 11 2023 ،‫تشرين األول‬  :Cobalamine.Vit B12 -7 Vitamin B12 (cobalamine) is one of the most complex low-molecular- weight substances occurring in nature. The core of the molecule consists of a tetrapyrrol system, with cobalt as the central atom. The vitamin is exclusively synthesized by microorganisms. It is abundant in liver, meat, eggs, and milk, but not in plant products. As the intestinal flora synthesize vitamin B12, strict vegetarians usually also have an inadequate supply of the vitamin. The liver is able to store vitamin B12 in PAGE 27 PAGE 26 amounts sufficient to last for.several months 15 vitamin water soluble - 11 2023 ،‫تشرين األول‬  Cobalamine can only be resorbed in the In animal metabolism, derivatives of small intestine when the gastric mucosa cobalamine are mainly involved in secretes what is known as intrinsic rearrangement reactions. For example, factor—a glycoprotein that binds they act as coenzymes in the cobalamine (the extrinsic factor) and conversion of methylmalonyl-CoA to thereby protects it from degradation. succinyl-CoA In the blood, the vitamin is bound to a.special protein known as transcobalamin Vitamin B12 deficiency is usually due to an absence of intrinsic factor that result in resorption disturbance. This leads to a disturbance in blood.formation known as pernicious anemia and in the formation of methionine PAGE 29 PAGE 28. from homocysteine 16 vitamin water soluble - 11 2023 ،‫تشرين األول‬  In prokaryotes, cobalamine derivatives If you have anemia caused by a vitamin B12 also play a part in the reduction of deficiency, you may have other symptoms in ribonucleotides. Homocysteine :addition to those listed above, such as methyltransferase and methylmalonyl.A sore and red tongue (glossitis)-1.Mouth ulcers-2 CoA mutase enzymes carry the.Changes in the way of walk and move around-3 coenzyme B12 to facilitate many.Disturbed vision-4 reactions in the pathways like.Irritability-5 methionine , SAM (S-Adenosyl.Depression-6 methionine), and odd number -carbon A decline in mental abilities, such as memory,-7.understanding and judgement (dementia) fatty acids.The deficiency may cause anemia which has a general signs like Extreme tiredness (fatigue)-1 Lack of energy (lethargy)-2 Breathlessness-3 Feeling faint-4 Headaches-5 Pale skin-6 Noticeable heart beats (palpitations)-7 31 31 Hearing sounds coming from inside the body,-8 PAGE PAGE 30 rather than from an outside source (tinnitus) PAGE Loss of appetite and weight loss-9 17 vitamin water soluble - 11 2023 ،‫تشرين األول‬  Folic acid :Other complications include.Anemia (low red blood cell count) -1 Folate, the anion of folic acid, is made Low levels of white blood cells -2 up of three different components—a.and platelets (in severe cases) pteridine derivative, 4-aminobenzoate, In folate- deficiency anemia, the and one or more glutamate residues. red blood cells are abnormally large After reduction to tetrahydrofolate (megaloblastic). Later, general (THF), folate serves as a coenzyme in damage ensues as phospholipid the C1 metabolism. Folate deficiency is synthesis and the amino acid relatively common, and leads to.metabolism are affected disturbances in nucleotide biosynthesis In contrast to animals,.and thus cell proliferation microorganisms are able to synthesize folate from their own components. The growth of microorganisms can therefore be inhibited by sulfonamides, which competitively inhibit the PAGE 33 incorporation of 4- aminobenzoate PAGE 32 into folate 18 vitamin water soluble - 11 2023 ،‫تشرين األول‬  Since folate is not synthesized in the animal organism,sulfonamides have no PAGE 35 PAGE 34.effect on animal metabolism 19 vitamin water soluble - 11 2023 ،‫تشرين األول‬  Thymidylate synthase the enzyme that carry the THF as a coenzyme is involved in the conversion of uridine to thymidine. Folate play a role in the purine synthesis pathway. Most common causes of depletion are alcoholics and pregnancy (body stores depleted in 3 months). The deficiency of folic acid may cause Homocystinemia with risk of* -1 deep vein thrombosis atherosclerosis* -2 Megaloblastic (macrocytic)* -3 'anemia Deficiency in early pregnancy PAGE 37 PAGE 36 causes neural tube defects in fetus 20 vitamin water soluble - 11 2023 ،‫تشرين األول‬  :Vitamin C Vitamin C is particularly abundant in fresh fruit and vegetables. Many soft drinks and food stuffs Vit C facilitates development of RBC's also have synthetic ascorbic acid added to them by enhancing iron absorption.as an antioxidant and flavor enhancer Vitamin C is L-ascorbic acid (chemically: hexuronic acid). The two hydroxyl groups have acidic properties. By releasing a proton, ascorbic acid therefore turns into its anion, ascorbate. Human, apes, and guinea pigs require vitamin C because they lack the enzyme L-gulonolactone oxidase (1.1.3.8), which PAGE 39 PAGE 38 catalyzes the final step in the conversion.of glucose into ascorbate 21 vitamin water soluble - 11 2023 ،‫تشرين األول‬  Boiling slowly destroys vitamin C. In the The daily requirement for ascorbic acid is body, ascorbic acid serves as a reducing about 60 mg, a comparatively large amount agent in variations reactions (usually for a vitamin. Vitamin C deficiency only hydroxylations). Among the processes occurs rarely nowadays; it becomes evident involved are collagen synthesis, tyrosine after a few months in the form of scurvy degradation, catecholamine synthesis, and ( poor wound healing, easy bruising or.bile acid biosynthesis perifollicular hemorrhage, bleeding gums, increased bleeding time, painful glossitis, anemia with connective-tissue damage, and tooth loss). Vitamin C enhances iron.absorption PAGE 41 40 PAGE40 PAGE perifollicular hemorrhage 22 vitamin water soluble - 11 2023 ،‫تشرين األول‬  Example of questions about vitamins Scurvy is a condition that affects Q1- what is the active form of vit B1? Explain people who eat grains but not fruit, as the coenzyme role of thiamine. Q2-The requirement of thiamine increase with well as socially isolated people, increase the load of carbohydrate in the diet --- inmates, and alcoholics who eat a poor why ? diet, and people who have Q3-What is the causes of lactic acidosis in thiamine deficiency? inflammatory bowel disease. Scurvy Q4-Explain how a deficiency of thiamine in the can occur in newborns of vitamin C- diet will cause serious effects on health Q5-A 40-year-old man with a 20-year history of deficient mothers since breast milk alcohol abuse is brought to the hospital by his.contains vitamin C friends because he was difficult to rouse. He ate a large meal several hours ago. He is emaciated and lethargic. Examination shows severely restricted horizontal eye movements and ataxia of both upper extremities. The most likely cause of these findings is a deficiency of which of the following nutrients? A. Folic acid B. Vitamin A C. Vitamin B1 (thiamine) D. Vitamin B6 (pyridoxine) PAGE 43 E. Vitamin B12 (cobalamin) PAGE 42 Correct answer : C. Vitamin B1 (thiamine) 23 vitamin water soluble - 11 2023 ،‫تشرين األول‬ THANKS 24 vitamin water soluble - 11 2023 ،‫تشرين األول‬