Vitamin C

1. Vitamin C By: Leslie Richards Matt Spaulding

2. 2 Table Of Contents Facts & History Structures Functions Stability Physiology and RDI Dietary Sources Deficiency

3. 3 Table of Contents cont. Toxicity Metabolic Reactions Vitamin C Quiz

4. 4 Facts and history Vitamin C is also called ascorbic acid. It is a water soluble vitamin. Most animals can synthesize their own vitamin c within its liver except for humans, primates, fish and guinea pigs. It is commonly added to foods as an antioxidant to protect color and aroma.

5. 5 Facts and history cont. Vitamin C can be used as a photographic developing agent when added to an alkaline solution. Vitamin C is used as a reducing agent industrially in metallurgy. 250 years ago, as many as two-thirds of a ship's crew died from vitamin C deficiency. The deficiency disease, called scurvy, was rampant in men who were at sea for long periods. In 1747 it was determined that only the sailors given citrus fruits recovered from scurvy. It wasn't until nearly 200 years later that vitamin C was identified.

6. 6 line structure 

7. 7 3-D Structure

8. 8 Functions Collagen Formation Antioxidant Activity Iron Absorption Synthesis of Vital Cell Compounds Immune System Function

9. 9 Stability In food, Vitamin C can be partially or completely destroyed by over cooking or storing for long periods of time. It is sensitive to heat, oxygen, and light.

10. 10 Physiology and rdI Structure closely resembles the structure of glucose. Absorption occurs primarily by active transport in the small intestine. Prior to absorption it may be oxidized to form dehydroascorbic acid. Because it is water soluble the body will excrete any excess.

11. 11 Physiology and rdi cont. RDI: 40 mg/day for adult males 30 mg/day for adult females Body is totally saturated at an intake of 150 mg/day.

12. 12 Dietary sources Black Currents (1/2 cup = 150 mg) Kiwi (1 medium = 75 mg) Grapefruit (1 medium = 94 mg) Orange (1 medium = 62 mg) Orange Juice (1/2 cup = 47 mg) Honeydew Melon (1/2 cup = 46 mg) Strawberries (1/2 cup = 41 mg) Cantaloupe (1/2 cup = 34 mg)

13. 13 Dietary sources cont. Tomato (1 medium = 23 mg) Brussels sprouts (cooked) (1/2 cup=59mg) Broccoli (cooked) (1/2 cup = 58 mg) Sweet Potatoes (cooked) (1/2 cup=28mg) Potato (cooked) (1/2 cup = 16 mg)

14. 14 deficiency Two early signs of deficiency are gums around the teeth bleed more easily, and the capillaries under the skin break spontaneously producing pinpoint hemorrhages. If the vitamin C pool becomes depleted to approximately one-fifth of its optimal size, scurvy develops (20-40 days on a vitamin C-free diet).

15. 15 Deficiency (scurvy) Scurvy is characterized by hemorrhaging; depleting muscles including the heart. Symptoms include rough, brown, dry, scaly skin; deep bruises, wounds failing to heal; opening of old scars; and failure of bone rebuilding. The appearance of anemia, infections and psychological symptoms indicate progression of the disease.

16. 16 Deficiency (scurvy) Once diagnosed it can easily be reversed. A dose of about 100 mg/day of Vitamin C will cure scurvy within 5 days and the dose can easily be supplied by food alone. When scurvy appears in children it is called �scorbutic infant�. Movement is painful. Bone growth is retarded and anemia are common.

17. 17 Toxicity Doses above 1 g/day can cause nausea, abdominal cramps, diarrhea, and kidney stones. Excess vitamin C can cause iron overload. Doses of vitamin C ten times the RDI may reduce the food availability of B12 by converting it to a biologically inactive form.

18. 18 Metabolic reactions The most important reaction involving vitamin c is the hydroxylation of proline residues in collagen with vitamin c as a cofactor. This process is required for maintenance of normal connective tissue It is also required for wound healing since synthesis of connective tissue is the first event in wound tissue remodeling. It also is necessary for bone remodeling due to the presence of collagen in the organic matrix of bones

19. 19 Metabolic reactions cont. Several other metabolic reactions require vitamin C as a cofactor. These include the catabolism of tyrosine and the synthesis of epinephrine from tyrosine and the synthesis of the bile acids.

20. 20 TYROSINE METABOLISM Tyrosine 3, 4-dihydroxyphenylalanine (Dopa) Dopamine Dopamine mono-oxygenase Cu1+ Vitamin C Norepinephrine

21. Vitamin c quiz

22. Which of the following is the correct line structure for Vitamin C? A. B. C. D.

23. 23 INCORRECT�

24. 24 INCORRECT� I�m sorry!! Vitamin C does not contain any nitrogens, cyclohexanes, or carboxylic acid functional groups.

25. 25 CORRECT!!! Congratulations!!! You selected Vitamin C!!!

26. 26 INCORRECT� I�m sorry! Vitamin C�s structure does not contain any cyclohexanes or an extended hydrocarbon chain. This structure has a molecular formula of C29H50O2

27. Which structure does Vitamin C most closely resemble? Glucose Fructose Vitamin A Glycogen

28. 28 CORRECT!!! Good Job!!! You selected glucose!! Glucose has a similar molecular formula with alcohol side groups.

29. 29 INCORRECT� I�m Sorry!! Although Fructose is a monosaccharide with the same empirical formula as glucose (C6H12O6), it has a different structure existing as a 5-member furanose ring.

30. 30 INCORRECT� I�m sorry!! This structure has many different possible geometric isomers as a result of either a trans or cis configuration of the four double bonds found in the polyene chain. Vitamin C�s structure does not have these characteristics.

31. 31 INCORRECT�

32. Because of vitamin C�s solubility the human body will: Store it as energy Excrete any excess Completely digest None of the above

33. 33 INCORRECT� Vitamin C does not contain any energy yielding compounds such as phosphates or glucose.

34. 34 CORRECT!! Good job!!! The human body will not store any excess Vitamin C due to it being a water soluble vitamin. It will be excreted through a person�s urine.

35. 35 INCORRECT� Due to its solubility in water certain amounts will pass through a person�s body with other water.

36. 36 INCORRECT!

37. 37 Which of the following cannot synthesize Vitamin C? Dogs Cats Birds Primates

38. 38 INCORRECT� Dogs can synthesize their own vitamin C! They have the necessary enzymes to catalyze these reactions.

39. 39 INCORRECT� Cats can synthesize their own vitamin C! They have the necessary enzymes to catalyze these reactions

40. 40 INCORRECT� Birds can synthesize their own vitamin C! They have the necessary enzymes to catalyze these reactions

41. 41 CORRECT!!! Primates cannot synthesize their own vitamin C. They lack glulonolactone oxidase, which is needed in the last step of the process which synthesizes ascorbic acid. They must obtain it from external sources.

42. 42 Vitamin C is a coenzyme in which part of tyrosine metabolism? Tyrosine 3,4-dihydroxyphenylalanine Tyrosine 3,4-dihydroxyphenylalanine dopamine C. Dopamine norepinephrine Acetoacetic acid acetoacetyl CoA

43. 43 INCORRECT� Although this is a reaction in tyrosine metabolism it does not involve Vitamin C as a coenzyme.

44. 44 INCORRECT� Although this is a reaction in tyrosine metabolism it does not involve Vitamin C as a coenzyme

45. 45 CORRECT!!! Vitamin C along with Cu1+ and the action of dopamine mono-oxygenase produces norepinephrine.

46. 46 INCORRECT� This reaction is a part of tyrosine catabolism.

47. 47 Vitamin C, also called abscorbic acid, is a water soluble vitamin that humans, as well as other primates, cannot synthesize. Vitamin C plays a big role in antioxidant reactions and can be found in citrus fruits and some vegetables. It acts as a coenzyme in many metabolic reactions including the synthesis of collagen and tyrosine metabolism/catabolism. Vitamin C is an essential part of the human diet, as too little results in scurvy as well as an impaired immune system. We hope that you enjoyed our presentation and learning about Vitamin C. Thank you!