Lecture 7b- 27 October 2014

Vitamins in metabolism and regulation

Most of this lecture taken from Chapters 7,10,11 of Rolfes et al(Understanding Normal and Clinical Nutrition(Nutrition 2104/2105 text)

Outline of lectures 7a,bVitamins    Definition of vitamins    Overview    Bioavailability    Precursors    Organic nature    Solubility        Water soluble vitamins        Fat soluble vitamins    Toxicity    Class exercise

Outline of lectures 7a,b

Water Soluble vitamins

    B vitamins and C    Found in what foods   

Outline of lectures 7a,b

B class-roles in metabolism and regulation of metabolism

        Thiamine        Riboflavin        Niacin        Biotin        Pantothenic acid        B6

        folate        B12

        Class exercise

Outline of lectures 7a,bFat soluble vitamins

    Found in what foods

    Fat soluble vitamins class-roles in metabolism and regulation of metabolism

        A        D        E        K    Class exercise

More detailed comments

Water Soluble vitamins    B vitamins and C    Found in what foods        Thiamine-whole grains

        Riboflavin-milk products or whole grains

        Niacin-meat, eggs, fish, poultry, whole grains

        Biotin-widespread in foods, organ meats, egg yolks, soybeans, fish, whole grains, GI bacteria

       

Water Soluble vitamins    B vitamins and C    Found in what foods           Pantothenic acid-widespread in foods, organ

meats, broccoli, whole grains

        B6-meat, fish, poultry, legumes, fortified

cereals

        folate-fortified grains, leafy green vegetables, legumes

        B12-animal products, fortified cereals

B class-roles in metabolism and regulation of metabolismThiamine-part of thiamine pyrophosphate

(TPP)-a coenzyme-small organic molecule that associates closely with certain  enzymes                                                                               

-TPP removes carbon from pyruvate to make acetyl

CoA                                                                                TPP participates in Krebs cycle       

B class-roles in metabolism and regulation of metabolism

Riboflavin-part of co-enzymes FMN(flavin mononucleotide) and FAD(flavin adenine dinucleotide) (used in energy metabolism)

                       -used in energy metabolism

       

B class-roles in metabolism and regulation of metabolism

Niacin-part of co-enzymes NAD(nicotinamide adenine dinucleotide) and NADP(its phosphate form)-used in energy metabolism

Biotin-part of coenzyme used in energy metabolism, fat synthesis, amino acid metabolism and glycogen synthesis

Pantothenic acid-part of co-enzyme A-used in energy metabolism

B class-roles in metabolism and regulation of metabolism

B6-part of coenzymes PLP(pyroxidal phosphate)

and PMP(pyridoxamine phosphate) used in amino acid and fatty acid metabolism; helps convert tryptophan to niacin and

serotonin

folate-part of THF(tetrahydrofolate) and DHF(dihydrofolate) used in DNA synthesis

       

B class-roles in metabolism and regulation of metabolism

B12-part of coenzymes methylcobalamin and

deoxyadenosylcobalamin used in new cells synthesis(THF metabolism)

      -reforms folate coenzyme

      -assists in catabolism of some fatty acids and amino acids

-figure 10-13

       

Fig. 10-13, p. 347

                                                       

file:///E:/Media/Animations/chapter10/Coenzyme_Action/0709.html

E:\Media\Animations\chapter10\Metabolic_Pathways\1013.html

B VITAMINS

REGULATION OF METABOLISM IS BY DEGREE OF PRESENCE OF CORRECT FORM OF VITAMIN

Vitamin C- found in what foods –

-citrus fruits, cabbage type vegetables, dark green vegetables(bell peppers and broccoli), cantaloupe, strawberries, lettuce, tomatoes, potatoes, papaya, mangoes

Vitamin C-functions

        -collagen synthesis        -forms scar tissue(collagen)        -forms collagen matrix for bone growth        -antioxidant (toxic doses-prooxidant)        -thyroxin synthesis        -amino acid metabolism(conversion of

tryptophan to serotonin and norepinephrine)

         -helps in absorption of iron                                                   

Vitamin C-regulation of metabolism

       REGULATION OF METABOLISM IS BY DEGREE OF PRESENCE OF CORRECT FORM OF VITAMIN                                                    

Class exercise  

Explain the connections between sourceand function of each of the water soluble vitamins

                                                  

Fat soluble vitamins    Found in what foods        A- retinol-fortified milk, cheese, cream, eggs,

liver            -Beta-carotene-spinach, dark leafy greens,

broccoli, apricots, cantaloupe, carrots, sweet potato

        D-sunlight, fortified milk, butter, cereals; veal, fish

        E-polyunsaturated plant oils, leafy green vegetables, liver, yolks

        K-gi bacteria synthesis, leafy green vegetables, cabbage type vegetables, milk

Fat soluble vitamins class-roles in metabolism and regulation of metabolism        A -retinol-protein synthesis                        -rhodopsin synthesis                        -not antioxidant(lipids)                  -Beta-carotene-antioxidant        D-regulates bone mineral metabolism,

primarily calcium

        E-antioxidant of lipids(fatty acids)        K-activates blood clotting proteins

                                                   

FAT SOLUBLE VITAMINS

REGULATION OF METABOLISM IS BY DEGREE OF PRESENCE OF CORRECT FORM OF VITAMIN                                                   

Class exercise

            Explain the connections between sourceand function of each of the fat soluble vitamins