Vitamins and cofactor in biochemsitrys.pptx

health

1. VITAMINS & cofactors ( occurrence, structures and biochemical function of vitamins a, b complex, c, d and e)

2. INTRODUCTION TO VITAMINS Organic chemical compounds, essential for normal cell function, growth, and development. Required in tiny amounts. C annot be synthesized in sufficient quantities. M ust be obtained from the diet. Provide no energy. Naturally found in plants and animals. Also be referred as micronutrients.

3. FUNCTIONS Essential for normal growth and metabolism. Deficiency of specific vitamins can lead to diseases. Excess amounts can also be dangerous. Support the immune system. Play a role in digestion & utilization of protein, fat & carbohydrates. Components of enzymes.

4. TYPES OF VITAMINS Fat-Soluble Vitamins Water-Soluble Vitamins

5. Definition and Classification Fat soluble vitamins Found in the fats and oils of food. Absorbed into the lymph and carried in blood with protein transporters = chylomicrons . *Stored in liver and body fat and can become toxic if large amounts are consumed.

6. Definition and Classification Water soluble vitamins Found in vegetables, fruit and grains, meat. Absorbed directly into the blood stream Not stored in the body and toxicity is rare. Alcohol can increase elimination, smoking, etc. cause decreased absorption.

7. Fat Soluble Vitamins Vitamin A (precursor – beta carotene) 3 forms: retinol (stored in liver), retinal, retinoic acid Roles in body: Regulation of gene expression Part of the visual pigment rhodopsin, maintains clarity of cornea (yes eating carrots is good for your eyesight) Required for cell growth and division - epithelial cells, bones and teeth Promotes development of immune cells, especially “Natural Killer Cells” Antioxidant

8. Fat Soluble Vitamins Vitamin A Deficiencies cause: Night blindness, xerophthalmia (keratin deposits in cornea), macular degeneration. Skin and mucous membrane dryness and infection, keratin deposits. Anemia Developmental defects – bones, teeth, immune system, vision

9. Fat Soluble Vitamins Vitamin A Toxicities (RetinA/Accutaine, single large doses of supplements, eating excessive amounts of liver) cause: Fragile RBCs, hemorrhage Bone pain, fractures Abdominal pain and diarrhea Blurred vision Dry skin, hair loss Liver enlargement

10. Fat Soluble Vitamins Vitamin A DRI: 700(women)-900(men) micrograms/day, UL 3000 micrograms Sources, see snapshot 7.1

11. Snapshot 7-1, p, 219

12. Fat Soluble Vitamins Vitamin D – precursor is cholesterol, converted by UV from sunlight exposure, therefore is a “non-essential” vitamin. Roles: Increases calcium absorption in bone, intestines, kidney. Promotes bone growth and maintenance. Stimulates maturation of cells – heart, brain, immune system, etc.

13. Fat Soluble Vitamins Vitamin D Deficiencies: rickets (children), osteomalacia (adults). What are some of the causes of deficiencies? Toxicities (5X DRI) Loss of calcium from bone and deposition in soft tissues. Loss of appetite, nausea and vomiting, psychological depression.

14. Fig. 7-5a, p. 222 Bowed legs – Characteristic of rickets

15. Fig. 7-5b, p. 222 Beaded ribs – Characteristic of rickets

16. Fat Soluble Vitamins Vitamin D DRI – 5 micrograms/day for ages 19-50, 10 for ages 51-70, 15 for ages >70. Sources, see snapshot 7.2

17. Snapshot 7-2, p, 223

18. Fat Soluble Vitamins Vitamin E – tocopherol, *alpha-, beta -, gamma-, and delta- Roles: Antioxidant (protects polyunsaturated fats) Prevention of damage to lungs, RBCs, WBCs (immunity), heart Necessary for normal nerve development

19. Fat Soluble Vitamins Vitamin E Deficiencies (decreased absorption of fats- liver disease, low fat diets) Premature babies – fragile RBCs (hemolysis) Loss of muscle coordination, vision, immune functions Toxicities (more than 1000 milligrams/day) Increases the effects of anticoagulants (Coumadin, Warfarin)

20. Fat Soluble Vitamins Vitamin E DRI 15 milligrams/day (alpha-tocopherol) Sources, see snapshot 7.3

21. Snapshot 7-3, p, 226

22. Fat Soluble Vitamins Vitamin K – produced by bacteria in large intestine Roles Promotes synthesis of blood clotting proteins (**Interferes with Coumadin) Bone formation Deficiencies are rare but seen in infants, after prolonged antibiotic therapy, and in patients with decreased bile production. Toxicities (>1000 mg/day): rupture of RBCs and jaundice

23. Fat Soluble Vitamins Vitamin K DRI: 90(women) – 120(men) micrograms/day Sources, see snapshot 7.4

24. Snapshot 7-4, p, 228

25. Water soluble vitamins

26. WATER-SOLUBLE VITAMINS Dissolve in water when they are ingested, and then go in blood stream Absorbed directly in the blood Travel freely Excess is excreted in the urine Needed in frequent doses Must be consumed regularly Less likely to reach toxic concentration in body Act as coenzymes Found in vegetables, fruit and grains, meat

27. TYPES OF WATER –SOLUBLE VITAMINS Vitamin C 8 B vitamins Vitamin B1 (Thiamin) Vitamin B2 (Riboflavin) Vitamin B3 (Niacin) Vitamin B5 ( Pantothenic acid) Vitamin B 6 (Pyridoxine) Vitamin B7 (Biotin) Vitamin B9 ( Folate or Folic Acid) Vitamin B 12 ( Cobalamins )

28. VITAMIN C Main Forms: Ascorbic acid, Hexuronic acid Anti-scorbutic vitamin Chemical Structure/Molecular Formula: WATER SOLUBLE VITAMINS VITAMIN C

29. FUNCTIONS Immune stimulation Anti-allergic Antioxidant “Cement” for connective tissues Wound healing Teeth and gum health Aids iron absorption Eye health WATER SOLUBLE VITAMINS VITAMIN C

30. DIETARY RESOURCES Vitamin C is widely distributed in fruits & vegetables. Rich resources are: Citrus fruits Blackcurrants Peppers Green vegetables Fruits like strawberries, guava, mango and kiwi WATER SOLUBLE VITAMINS VITAMIN C

31. DEFICIENCIES Scurvy Weakness Lassitude Swollen gums Nosebleeds WATER SOLUBLE VITAMINS VITAMIN C

32. TOXICITY Increases the amount of uric acid in urine Can get stored in the kidney, resulting in kidney stone Leads to excess absorption of iron, leading to a condition known as hemochromatosis Increased acid levels Diarrhea & Abdominal cramps Skin rash Nausea Erosion of dental enamel WATER SOLUBLE VITAMINS VITAMIN C

33. Water Soluble Vitamins 8 B vitamins – T ender R omance N ever F ails with 6 to 12 B eautiful P earls (Thiamin, Riboflavin, Niacin, Folate, B 6 , B 12 , Biotin, and Pantothenic acid) Aid in metabolism of and energy release from carbohydrates, lipids, amino acids. Mode of action – coenzymes or parts of coenzymes that are necessary for the proper activity of enzymes, fig 7.9

34. Fig. 7-9a, p. 233 Compounds Active site Enzyme Without the coenzyme, compounds A and B don’t respond to the enzyme. A B With the coenzyme in place, compounds A and B are attracted to the active site on the enzyme, and they react. Enzyme A B Vitamin Coenzyme The reaction is completed with the formation of a new product. In this case, the product is AB. Enzyme Enzyme A B The product AB is released. New product A B

35. Fig. 7-10, p. 234 Muscles and other tissues metabolize protein. Brain and other tissues metabolize carbohydrates. Bone tissues make new blood cells. Liver and other tissues metabolize fat. Digestive tract lining replaces its cells.

36. VITAMIN B1 (THIAMIN)

37. Common names: Thiamin/thiamine Antiberiberi factor Aneurine Nerve vitamin Chemical Structure/Molecular Formula: WATER SOLUBLE VITAMINS VITAMIN B 1

38. FUNCTIONS Main functions are: Co-enzyme in energy metabolism Co-enzyme for pentose metabolism as a basis for nucleic acids Nerve impulse conduction and muscle action WATER SOLUBLE VITAMINS VITAMIN B 1

39. DIETARY RESOURCES The best source of thiamin is dried brewer’s yeast. Other good sources include: Meat Some species of fish ( eel) Whole grain cereals and bread Nuts Pulses Dried legumes Potatoes WATER SOLUBLE VITAMINS VITAMIN B 1

40. DEFICIENCIES Beriberi Abnormal blood sugar Depression Fatigue Nausea Vomiting Gastrointestinal disorders WATER SOLUBLE VITAMINS VITAMIN B 1

41. TOXICITY Increased pulse rate Insomnia Irritability Weakness Headache High blood pressure Skin eruptions Hypersensitivity WATER SOLUBLE VITAMINS VITAMIN B 1

42. VITAMIN B 2 - RIBOFLAVIN

43. Common names: Riboflavin/ riboflavine Lactoflavin Chemical Structure/Molecular Formula: WATER SOLUBLE VITAMINS VITAMIN VITAMIN B 2

44. FUNCTIONS Oxidation-reduction reactions Energy production Conversion of pyridoxine (vitamin B6) and folic acid into their active coenzyme forms Growth and reproduction Growth of skin, hair, and nails VITAMIN B 2 WATER SOLUBLE VITAMINS VITAMIN B 2

45. DIETARY RESOURCES Milk and milk products Lean meat Eggs Green leafy vegetables Fortified cereals and bakery-products supply large amounts. VITAMIN B 2 WATER SOLUBLE VITAMINS VITAMIN B 2

46. DEFICIECIES Trouble Digesting Food Experience Dizziness Frequently Issues with Hair Loss, Skin or Vision, Bloodshot eyes Slow Mental Responses Insomnia Sore tongue and lips Infection in the mouth and throat Extreme and unusual sensitivity to light Chapped lips WATER SOLUBLE VITAMINS VITAMIN B 2

47. TOXICITY Itching Numbness Sensitivity to light WATER SOLUBLE VITAMINS VITAMIN B 2

48. NIACIN

49. Common names: Vitamin B3 & Vitamin B4 PP factor (pellagra-preventative factor) Forms: Nicotinamide & nicotinic acid Both are used to form the coenzymes nicotinamide adenine dinucleotide (NAD) & nicotinamide adenine dinucleotide phosphate (NADP). Chemical Structure/Molecular Formula: WATER SOLUBLE VITAMINS NIACIN

50. FUNCTIONS Coenzymes (NAD and NADP) in redox reactions NAD is a substrate for non- redox reactions WATER SOLUBLE VITAMINS NIACIN

51. DIETARY RESOURCES Nicotinic acid is more prevalent in plants In animals, nicotinamide predominates Yeast , liver, poultry, meats , nuts & legumes Milk & green leafy vegetables contribute lesser amounts WATER SOLUBLE VITAMINS NIACIN

52. Snapshot 7-8, p, 238

53. DEFICIENCIES Fatigue Depression Swollen mouth and bright red tongue Vomiting and diarrhea Apathy Memory loss WATER SOLUBLE VITAMINS NIACIN

54. TOXICITY Flushed face Upset stomach Itching Jaundice Blurry vision Stomach ulcers Elevated blood sugar Worsening of diabetes Worsening of gout WATER SOLUBLE VITAMINS NIACIN

55. VITAMIN B 6

56. Main forms: Vitamin B6 is composed of three forms ( vitamers ): pyridoxine or pyridoxol (the alcohol) pyridoxal  (the aldehyde ) pyridoxamine  (the amine) Chemical Structure/Molecular Formula: WATER SOLUBLE VITAMINS VITAMIN B 6

57. FUNCTIONS Nervous system (neurotransmitter synthesis) Red blood cell formation Niacin formation Immune system (antibody production) Steroid hormones (inhibition of the binding of steroid hormones ) WATER SOLUBLE VITAMINS VITAMIN B 6

58. DIETRY RESOURCES Pyridoxine is found especially in plants. Excellent sources of pyridoxine are chicken & the liver of beef, pork and veal. Pyridoxal and Pyridoxamine are principally found in animal tissue. Good sources include: Fish (salmon, tuna, sardines, halibut, herring) Nuts (walnuts, peanuts) Bread Corn and whole grain cereals. WATER SOLUBLE VITAMINS VITAMIN B 6

59. DEFICIENCIES Lack of Energy A Decrease in Brain Function High Levels Of Homocysteine WATER SOLUBLE VITAMINS VITAMIN B 6

60. TOXICITY Nerve Irritation Headaches Severe Fatigue Mood Changes Nerve Damage Trembling WATER SOLUBLE VITAMINS VITAMIN B 6

61. FOLACIN

62. Common names: Folic acid vitamin BC vitamin B9 WATER SOLUBLE VITAMINS FOLACIN Chemical Structure/Molecular Formula:

63. FUNCTIONS Main functions are: Coenzyme in amino acid metabolism Coenzyme in the synthesis of nucleic acids Blood cell formation in the bone marrow WATER SOLUBLE VITAMINS FOLACIN

64. DIETARY RESOURCES Liver Dark green leafy vegetables Beans Wheat germ Yeast Egg yolk Milk & dairy products Orange juice Whole wheat bread WATER SOLUBLE VITAMINS FOLACIN

65. DEFICIENCIES Anemia Bleeding symptoms Intestinal symptoms Malabsorption Red, irritated, sometimes shiny tongue WATER SOLUBLE VITAMINS FOLACIN

66. TOXICITY Diarrhea Insomnia Irritability WATER SOLUBLE VITAMINS FOLACIN

67. VITAMIN B 12

68. Common names: Cobalamin Castle’s extrinsic factor Animal protein factor WATER SOLUBLE VITAMINS VITAMIN B 12 Chemical Structure/Molecular Formula:

69. FUNCTIONS Essential growth factor Formation of blood cells and nerve sheaths Regeneration of folic acid Coenzyme-function in the intermediary metabolism, especially in cells of the nervous tissue, bone marrow & gastrointestinal tract WATER SOLUBLE VITAMINS VITAMIN B 12

70. DIETARY RESOURCES Vitamin B12 is produced exclusively in the digestive tract of animals. Animal protein products are the source of vitamin B12 in the human diet, in particular organ meats (liver, kidney). Other good sources are fish, eggs and dairy products. WATER SOLUBLE VITAMINS VITAMIN B 12

71. DEFICIENCIES Chest pain or heart palpitations Confusion, depression, memory loss Constipation Dizziness, trouble maintaining balance, and fainting Numbness or coldness of hands and feet Pale skin or jaundice (yellowing of skin and eyes) Poor appetite Shortness of breath Sore mouth and tongue Weight loss Irregular menstruation WATER SOLUBLE VITAMINS VITAMIN B 12

72. TOXICITY Diarrhea Blood clots in the legs Feelings of swelling over the entire body Signs of an allergic reaction, such as: Hives or a rash Itching Swelling of the lips, mouth, or throat WATER SOLUBLE VITAMINS VITAMIN B 12

73. PANTOTHENIC ACID

74. Common names: Vitamin B5 Antidermatosis vitamin Chick antidermatitis factor Chick antipellagra factor WATER SOLUBLE VITAMINS PANTOTHENIC ACID Chemical Structure/Molecular Formula:

75. FUNCTIONS Metabolism of carbohydrates, proteins & fats Supply of energy from foods Synthesis of essential lipids, sterols, hormones, neurotransmitters Metabolism of drugs and alcohol detoxification WATER SOLUBLE VITAMINS PANTOTHENIC ACID

76. DIETARY RESOURCES Yeast Organ meats (liver, kidney, heart, brain ) Milk Vegetables Legumes Whole grain cereals WATER SOLUBLE VITAMINS PANTOTHENIC ACID

77. DEFICIENCIES Fatigue and Apathy Numbness & Cramps Hypoglycemia Excessive Stress Insomnia Rheumatoid Arthritis Poor Blood Profile WATER SOLUBLE VITAMINS PANTOTHENIC ACID

78. TOXICITY Intermittent diarrhea WATER SOLUBLE VITAMINS PANTOTHENIC ACID

79. BIOTIN

80. Common names: Vitamin H (“ Haar und Haut ”, German words for “hair and skin”) vitamin B8 WATER SOLUBLE VITAMINS BIOTIN Chemical Structure/Molecular Formula:

81. FUNCTIONS Synthesis of fatty acids, amino acids & glucose Energy metabolism Excretion of by-products from protein metabolism Maintenance of healthy hair, toenails & fingernails WATER SOLUBLE VITAMINS BIOTIN

82. DIETARY RESOURCES Yeast Liver Kidney Egg yolk Soybeans Nuts Cereals WATER SOLUBLE VITAMINS BIOTIN

83. DEFICIENCIES Dermatitis Hyperesthesia Keratoconjunctivitis Anorexia Anemia WATER SOLUBLE VITAMINS BIOTIN

84. TOXICITY Oral supplementation with Biotin has not shown to be toxic. WATER SOLUBLE VITAMINS BIOTIN

85. cofactors Cofactors are small molecules or compounds that bind to enzymes and allow the enzymes to function. Cofactors are not proteins nor amino acids. Enzymes catalyze many type of reactions. However, most of the enzymes require the presence of cofactors in order to be active. The cofactor's role and mechanism varies with different enzymes. Usually, cofactors perform chemical reactions that the twenty amino acids cannot undergo. Proteins can perform acid-base reactions, form certain covalent bonds, and engage in intermolecular interactions. However, proteins are not equipped to facilitate reactions involving oxidation-reduction and group transfers.

86. Cofactors (continued) Inactive enzymes without a cofactor attached are referred to as apoenzymes . Conversely, enzymes that are complete with cofactors and ready to catalyze reactions are called holoenzymes . There are two categories of cofactors: metals and coenzymes. Metal cofactors are essentially metal ions, such as Zn 2+ , Mg 2+ , and Ni 2+ . Coenzymes are small organic compounds, commonly generated from vitamins. Furthermore, coenzymes are characterized by how strong they bind to their respective enzymes. Coenzymes that bind strongly to enzymes are called prosthetic groups . The enzyme-coenzyme complexes with prosthetic groups are generally permanent. In others words, the prosthetic group does not dissociate from the enzyme. Coenzymes that loosely bind to enzymes function like co-substrates . In this case, the enzyme-coenzyme complexes can form and dissociate, which make the enzyme active or inactive.