NS 4320: Lecture 13: Vitamins
Vitamin B12 we had studied as a coenzyme during ____
isomerization of Succinyl CoA in CAC.
Vitamins E & K are
less understood vitamins
Vitamin D is then stored (in __&__) becomes a vitamin if
(liver and kidney) Becomes a vitamin if synthesis is insufficient "conditional vitamin"
Vitamin K: 1 function: addition of ___ to proteins -synthesis of ____ ____-binding amino acid role in ___, ___, & ___ (3) - BBK
1 Function: addition of CO2 (carboxylation) to proteins synthesis of g-carboxyglutamatic acid Calcium-binding amino acid Role in blood clotting, bone formation/remodeling, and kidney Ca resorption
PLP the active coenzyme form of B6 is closely associated with the metabolism of amino acids: (5: TDHDP)
1) transamination 2) decarboxylation 3) heme synthesis 4) deamination 5) production of niacin
Beta-carotene is a ___ provitamins are ____
A provitamin Provitamins are inactive precursors that must be converted to active forms in the body.
Functions of beta-carotene (2: WE)
A weak antioxidant Effective against oxidation in cell membranes and LDLs
Vitamin B12: Absorption & Storage Absorption of B12 requires a glycoprotein known as ___ B12 is stored in the liver in the form of ____
Absorption of Vitamin B12 requires a Glycoprotein known as intrinsic factor produced in the stomach in the presence of HCl. Stored in the liver in the form of Deoxyadenosyl Cobalamin.
Vitamin K deficiency: acute & subacute
Acute: You bleed to death. Subacute: problems with bone minerals VK deficiency may be risk factor for osteoporosis!
Functional classes of vitamins: (7: AECD1AH)
Acyl/acetyl transfer reactions: Pantothenate (B5) Electron transfer reactions: Riboflavin (B2), Niacin (B3) Carboxylation reactions: Biotin, Vitamin K Decarboxylation reactions: Thiamin (B1), Pyridoxine (B6) 1-carbon transfer reactions: Folate, Vitamin B12 Antioxidant reactions: Vitamin C, Vitamin E Hormones: Vitamin A, Vitamin D
Vitamin K & Ca binding: allows regulated _____ association no Ca = with Ca =
Allows regulated protein-membrane association no Ca, charged group repulsed by membranes with Ca, uncharged- no repulsion
Vitamin C functions: antioxidant role & immunological function
Antioxidant Role: Vitamin C acts as an antioxidant preventing tissue injury due to oxidative damage by free radicals: • Fights infection. • Reduces the risk of cancer and coronary artery disease. Immunological Function: Vitamin C enhances the synthesis of Immunoglobulins (antibodies) and increases the phagocytic functions of leukocytes.
Functions of Vitamin A (5: AVCSB)
Antioxidant:protects LDL from oxidation Essential for proper vision Cell differentiation, process by which stem cells mature into specialized cells Sperm production and fertilization Bone growth
Vitamin C is also known as
Ascorbic Acid
Beta carotene recommended intake
Beta-carotene is not considered an essential nutrient. No Dietary reference in take (DRI) or Recommended dietary allowance (RDA) has been established.
Biotin coenzyme form is ____ Biotin is a prosthetic group of ____
Biocytin is the coenzyme form of Biotin Biotin is a prosthetic group of carboxylase
Biotin chemistry: is a ___ is ___ derivative it is formed by ____ biotin covalently bound to ___ to form ____
Biotin (B7) is a heterocyclic sulfur containing monocarboxylic acid Biotin is imidazole derivative It is formed by fusion of imidazole & thiophene rings with a valeric acid side chain Biotin covalently bound to ε - amino group of lysine to form biocytin
Biotin deficiency is generally not seen in humans because of synthesis of vitamin by the ____ in the gut
Biotin deficiency is generally not seen in humans because of its wide distribution in foods Synthesis of vitamin by the bacterial flora in the gut
Biotin biochemical functions: required for ___ reactions required for the enzymes: (4)
Biotin is required for carboxylation reactions (CO2 fixation reaction) Biotin is required for the enzymes: -Pyruvate carboxylase -Acetyl CoA carboxylase -Propionyl carboxylase -β - Methyl crotonyl CoA carboxylase
Vitamin A Acute toxicity symptoms (4: BNIH)
Blurred vision Nausea, vomiting, vertigo Increase of pressure inside skull, mimicking brain tumor Headaches
Now, prothrombin, when it binds to calcium, guess whats realeased at the site of a wound, when you have a wound.. ___ prothrombin gets localized to the wound bc
CALCIUM. Prothrombin gets localized to the wound b/c vit K makes this happen.
Vitamin D: Ergocalciferol and Cholecalciferol Cholecalciferol is made in the ___ by the action of ___ Major circulating form is ____ It functions to regulate ___ & plays a role in ____
Cholecalciferol is made in the skin by the action of UV light on 7-dehydrocholesterol Major circulating form is 25-hydroxyvitamin D 1,25-dihydroxycholecalciferol (1,25-dihydroxyvitamin D3) is the most active form It functions to regulate calcium homeostasis and plays a role in phosphorus homeostasis
Vitamin B12 is also known as ____
Cobalamin
Vitamin A deficiency (4: CTSC)
Corneal drying (xerosis), Triangular gray-foamy spots on eye (Bitot's spots) Softening of the cornea (keratomalacia) Corneal degeneration and blindness (xerophthalmia)
Dietary Vitamin D: __&__ are absorbed well RDA =
D2 and D3 are absorbed well RDA = 400 IU per day; 1000 IU/day
Problems with Vitamin D deficiency: decrease in ___ results in ___ loss of ___ lessened enhancement of ____ big problem: parathyroid hormone continues to ____
Decrease in circulating vitamin D levels Results in Ca deficiency Loss of enhanced intestinal absorption Lessened enhancement of kidney resorption and bone remodeling Big Problem- Parathyroid hormone (PTH) continues to enhance bone remodeling without increased dietary Ca absorption
There are two active coenzyme from VitaminB12: (DM)
Deoxyadenosyl Cobalamin Methylcolbalamin
Carotenoids in general are known to: (3: EPP)
Enhance the immune system Protect skin from damage by UV light Protect eyes from damage
Dietary Vitamin D: exits mucosa in ____ travels via ____
Exits mucosa in chylomicrons Travels via lymphatic system to thoracic duct where enters the blood
Free radicals are highly reactive with ___ VE protects cell membranes by directly reacting with ___
Fas. VE protects cell membranes by directly reacting with free radicals (so they can't react with membranes).
Vitamin A is a ___ soluble vitamin excess is stored in the (4) active forms: (3)
Fat-soluble vitamin Excess is stored in the liver, adipose tissues, kidneys, and lungs Active forms - Retinol, Retinal, Retinoic Acid
Vitamin D is a ___ vitamin, that requires ___ for absorption
Fat-soluble vitamin; requires micelles for absorption
Free radicals are molecules that have ____ If not neutralized, free radicals will react with ___, potentially changing ____ The end result can be an increased risk for ____ Also protects ___&___
Free radicals are molecules that have unpaired electrons, which give the molecules an electrical charge, thus making them unstable and highly reactive. If not neutralized, free radicals will react with molecules in the body, potentially changing these molecules structure and or function. The end result can be an increased risk for damage to tissues such as skin and connective tissue. Also protects membranes and genetic material (react with genes in nuclei which can lead to genetic mutations and could cause aberrant cell growth and/or cancer of virtually all tissues of the body)
Riboflavin: Deficiency Manifestation (3: GDC)
Glossitis: Smooth and purplish tongue. Dermatitis: Inflammation of the facial skin in particular. Cheilosis: Fissures at the corner of the mouth
Vitamin D toxicity is partly ____ serum ____ > 3.3 mM also ___, __, __, __, ___ (5) nasty, can be fatal
HYPERCALCEMIA Serum Ca2+ > 3.3 mM (normal 2.5 mM) Also, hyperphosphatemia, hypertension, renal stones, kidney failure, heart malfunction
Vitamin C is heat ___ in the process of cooking ___% of Vitamin C is lost Vitamin C does not have any active coenzyme form but acts as a ____
Heat sensitive and gets destroyed by cooking. In the process of cooking 70% of vitamin C is lost. Does not have any active coenzyme form but acts as a strong reducing agent.
Vitamin C deficiency is manifested as Scurvy which is characterized by: (7: HBJPFSL)
Hemorrhages under the skin bone fragility joint pain Poor wound healing frequent infections Spongy and bleeding gums loosened teeth
Vitamin D toxicity: high level 25-OH D3 has some toxicity of D3 occurs largely through ____ over addition of ____ supplements generally restricted to ____
High level 25-OH D3 has some hormonal activity Toxicity of D3 occurs largely thru supplement misuse Over-addition of D2 to milk Supplements generally restricted to RDA or less
Vitamin A deficiency problems: impaired ____ increased ____ bone ____ hyperkeratosis: -plugging of ____ -____
Impaired immunity (infections) Increased susceptibility to infections and increased death rates from infections like measles Bone deterioration Hyperkeratosis -Plugging of hair follicles with keratin, forming white lumps -Death
Vitamin A chronic toxicity symptoms: (3: IEB)
Increased activity of osteoclasts causing reduced bone density Liver abnormalities (enlarged) Birth defects
Riboflavin Structure: ___ ring attached to ___ stable to ___ but sensitive to ___. When exposed to UV rays it ____
Isoalloxazine ring attached to Ribitol. Stable to heat but sensitive to light (photosensitive). When exposed to UV rays it gets destroyed.
The branched chain α-Keto acid dehydrogenase (decarboxylase): catalyzes the conversion of a-keto acids to ____ essential for ____ TPP is required for synthesis of ____
It catalyses the conversion of α-keto acids to corresponding acyl CoA Essential for transmission of nerve impulse TPP is required for synthesis of Acetylcholine
α- Ketoglutarate dehydrogenase complex: converts ____ in TCA cycle
It converts α- Ketoglutarate succinyl CoA in TCA cycle
Folic acid structure & active form: is it composed of ___ Pteridine linked with ____ is called Pteroic acid it is then attached to ____ to form ___ active form is ____
It is composed of 3 constitutents. Pteridine linked with para-aminobenzoic acid (PABA) is called Pteroic acid. It is then attached to glutamate to form Folic acid. Active form is Tetrahydrofolic acid
Thiamine: Occurence it is present in large amounts in ___ it has a widespread distribution in foods, but ___ the half life of thiamine is ___ it is excreted by ____
It is present in large amounts in skeletal muscle, heart, liver, kidney, and brain. It has a widespread distribution in foods, but there can be a substantial loss of thiamine during cooking above 100°C (212°F). The half-life of thiamine is 9-18 days. It is excreted by the kidney.
Biotin is ___ soluble ___ containing _____
It is water soluble sulfur containing B-complex vitamin
Too much beta carotene:
Large quantities do not appear to be toxic. Carotenosis (Orange pigment to the body usually on the palms of the hands and soles of your feet) or carotenodermia is harmless and reversible
Lipoic acid, like biotin, is a ____ lipoid acid is an ____ carrier found in __&__
Lipoic acid, like biotin, is a ring on a chain and is linked to a lysine on its protein Lipoic acid is an acyl group carrier Found in pyruvate dehydrogenase and a-ketoglutarate dehydrogenase
Folic acid deficiency manifestation: (2: MN)
Macrocytic Anemia (large distorted RBC with immature nucleus) with megaloblasts in bone marrow. Neural tube defects: Folic acid deficiency during early pregnancy may lead to neural tube defects (Spina bifida) in the fetus. -malformed spinal cord protrudes from back- nerves at and below the protrusion are damaged
Many vitamins are ___ - molecules that bring ____ vitamins & coenzymes are classified as __&___
Many vitamins are "coenzymes" - molecules that bring unusual chemistry to the enzyme active site Vitamins and coenzymes are classified as "water-soluble" and "fat-soluble"
VitaminB12 Deficiency Manifestation: (2: MN)
Megaloblastic Anemia: the peripheral blood shows Megaloblasts with large immature nucleated RBC Nervous Manifestation: Degeneration of nervous system due to Demyelination
Who's at risk for K status? (3: NCA)
Newborns: - no VK stores Sterile gut- no contribution from gut bacteria Breast milk low in vitamin K Chronic Antibiotic Treatment: which wipe out gut sources of VK Anticoagulant Therapy: some anticoagulants block VK action Dicoumerol & Coumadins (aka Warfarin) Used in treatment of heart disease and stroke
Dietary Vitamin D is required in diet when synthesis is low: (3: NCS)
Northern latitudes complexion sun exposure (tanning booths and sunblock)
Folic acid causes of deficiency: (3: PDD)
Pregnancy: Increased requirement because of fast cell division. Diet: Absence of vegetables in diet. Drugs: Methotrexate (anti-cancer drug) inhibits Dihydrofolate reductase so no active THF is formed
Vitamin A: forms Retinol-binding proteins help to mobilize & transport ___
Retinol, retinyl esters and retinal are forms of Vitamin A Retinol-binding proteins (RBPs) help to mobilize and transport vitamin A and its derivatives
Vitamin A active forms: (3)
Retinol: Alcohol at the end of it Retinal: aldehyde at the end of it Retinoic acid: a carboxyl group
Biotin dietary sources: rich sources are ____ (7) poor sources are __&__ (2)
Rich sources are eggs, liver, kidney, & yeast, pulses, nuts, vegetables Poor sources are cereals & dairy products
Vitamin D deficiency (7: RLILOGK)
Rickets, osteomalacia loss of bone mineral Is really a Calcium Deficiency... An issue when dietary Ca is marginal Loss of hormonal actions of D3 Osteoclasts of bone Gut cells that absorb dietary Ca Kidney Ca resorption
Biotin deficiency: clinical manifestations severe __,___,___ (3) in animals: (3)
Severe dermatitis, weakness, & nausea In animals muscle weakness, dermatitis & loss of hair around the eye
Vitamin D deficiency symptoms: (4: SSPI) - BSPB
Skeletal deformities including bowed legs Spinal deformities (spine curves abnormally) Pelvic deformities Increased tendency toward bone fractures
Retinol
Storage form kept in the liver, so as the body needs other forms, its released.
Folic acid biochemical functions: the active coenzyme THF is involved in ____ THF serves as ___ or ___ of one carbon units in a variety of reactions involving ___&___ one carbon compound is an ____
The active coenzyme tetrahydrofolate (THF) is involved in One Carbon Metabolism. THF serves as acceptor or donor of one carbon units (formyl, methyl etc) in a variety of reactions involving amino acid and nucleotide metabolism. One carbon compound is an organic molecule that contains only a single carbon -Methyl (-CH3) -Methenyl (-CH=) -Methylene (-CH2-) -Formyl (-CHO)
Activation of thiamine: the alcohol group of thiamine is esterified with ____ to form the coenzyme ___ the phosphate moiety is donated by ___ & reaction is catalyzed by ____ thiamine is a ____ containing ___ soluble vitamin
The alcohol group of thiamine is esterfied with phosphate (2moles) to form the coenzyme, Thiamine pyrophosphate. The phosphate moiety is donated by ATP and reaction is catalyzed by TPP transferase. Thiamine is a sulphur containing water soluble vitamin.
Biochemical functions: the coenzyme, TPP or ____ is connected with ___ PDC: -catalyzes the ____ -it is essential for ____ -it links __&__
The coenzyme, TPP or Cocarboxylase is connected with energy releasing reactions in the carbohydrate metabolism Pyruvate dehydrogenase complex: It catalyses the irreversible conversion of pyruvate to acetyl CoA It is essential for complete oxidation of glucose It links glycolysis and TCA cycle
Riboflavin: biochemical functions the isoalloxazine ring serves as an acceptor of ____ the coenzymes ___ & ___ participate in many oxidation reduction reactions & in the ____
The isoalloxazine ring serves as an acceptor of two hydrogen atoms (with electrons) FMN --> FMNH2 FAD --> FADH2 • The coenzymes FMN(FMNH2) and FAD(FADH2) participate in many oxidation reduction reactions and in the Electron Transport Chain.
Too little beta carotene:
There are no known deficiency symptoms
Thiamine: Synthesis can be synthesized by __&__, but not usually ___ human beings require thiamine from diet, though small amounts may be obtained from ____ the body can only store up to ___ mg of thiamine in its tissues
Thiamine can be synthesized by plants and some microorganisms, but not usually by animals. Human beings require thiamine from diet, though small amounts may be obtained from synthesis by intestinal bacteria. The body can only store up to 30 mg of thiamine in its tissues.
Thiamine: Structure
Thiamine contains a substituted pyrimidine ring (dimethyl 6-amino pyrimidine) connected to a substituted thiazole ring (Methyl hydroxy ethyl thiazole) by means of Methylene bridge.
Metabolic role of thiamine: thiamine pyrophosphate is an essential cofactor for enzymes that catalyze the _____ these include ___, ___, & ____. These 3 enzymes operate by a similar catalytic mechanism
Thiamine pyrophosphate is an essential cofactor for enzymes that catalyze the oxidative decarboxylation of α-keto acids to form an acylated coenzyme A (acyl CoA). These include pyruvate dehydrogenase , α -keto glutarate dehydrogenase and branched-chain α-keto acid dehydrogenase. These three enzymes operate by a similar catalytic mechanism.
Transketolase is dependent on ___ it is involved in ____
Transketolase is dependent on TPP It is involved in HMP shunt
Vitamin D: UV irradiation of milk converts ___ into ___ ____ don't make Vit D- poor dietary sources
UV irradiation of milk converts ergosterol (a plant form) into ergocalciferol (Steenbock) Plants (and microbes) don't make Vit D- poor dietary sources
VitaminB12 Causes of Deficiency: (4: VDPP)
Vegetarians: Vitamin B12 is mainly present in animal diet Decreased absorption: Due to Gastrectomy and malabsorption diseases. Perinicious Anemia: Antibodies are formed against Intrinsic Factor leading to decreased absorption of Vitamin B12. Pregnancy, lactation and alcoholics:
Vitamin A importance
Vitamin A is important for eyes for vision Vitamin A is light sensitive, meaning that its chemical bonds, its full of double bonds flip from cis to trans in the presence of light. This flip is used as a way of signaling nerve cells in your retina. As a consequence of that flipping, the nerve cells send a signal to your brain saying, hey, we saw something here. Your brain then paints the picture that you see out here in the real world. If you don't have vitamin A, you go blind.
Riboflavin is also known as
Vitamin B2
Pyridoxine is also known as
Vitamin B6
Vitamin C biochemical functions: collagen formation Vit C required for hydroxylation of ___&___ the __&__ formed are essential for the ___ &___
Vitamin C is required for hydroxylation of proline and lysine. The hydroxyproline and hydroxylysine formed are essential for the collagen cross-linking and the strength of the fiber.
Vitamin E is a potent ____ molecular details are almost entirely ____ may prevent ____
Vitamin E (-tocopherol) is a potent antioxidant Molecular details are almost entirely unknown May prevent membrane oxidations
Vitamins are ___ required in the diet in small amounts to perform ____ the word vitamin comes from the Greek word ____ which means ___
Vitamins are organic compounds required in the diet in small amounts to perform specific biologic functions for normal maintenance of optimum growth and health. The word Vitamin comes from the Greek word "VITAMINE" which means 'Vital for Life.'
Examples of thiamine in food: (8)
Whole wheat flour, unpolished rice, beans, nuts and yeast are the good sources of thiamine It is also present in liver, meat and eggs.
A coenzyme is
a molecule that combines with an enzyme to activate it and help it do its job.
Retinal
aldehyde group Found in eyes
Vitamin B1 Thiamine- Introduction also known as ___ is an important ___ is involved in ____ is required as a coenzyme in ___ is essentially ____
also known as vitamin B1, anti beriberi factor or anti-neuritic vitamin is an important water-soluble vitamin is involved in carbohydrate, fat, amino acid, glucose, and alcohol metabolism. is required as a coenzyme in enzymatic reactions that involve the transfer of an aldehyde group. is essentially nontoxic.
Biotin is formerly known as
anti-egg white injury factor or vitamin H
*immunoglobulins are
antibodies
The B vitamins are particularly important in assisting ___ & include ______
assisting energy metabolism and include thiamin, riboflavin, vit B6, niacin, folate, vit B12, pantothenic acid and biotin.
Vitamin K is essential for:
blood clotting Carboxylation of 10 glutamyl residues on prothrombin (to form -carboxy-Glu residues) is catalyzed by a vitamin K-dependent enzyme, liver microsomal glutamyl carboxylase
Megaloblastic anemia should always be treated with both __&__
both folic acid and vitamin B12
Vit D is involved in the uptake of
calcium, its necessary for strong bones
Structurally Vitamin C resembles a
carbohydrate (hexose)
Retinoid acid
carboxyl group Very important for development as a cell develops
Biotin mainly participates in the
carboxylation reactions
Beta-carotene is in the class of chemicals called
carotenoids
Retinoic acid functions: (3: CBI)
cell differentiation bone health immune function
2 Forms of Vitamin D: D3 aka ___ form normally made by ___ made from ___ has 100% ____
cholecalciferol Form normally made by mammals Made from cholesterol Has 100% vitamin D activity
We make vitamin D from ___ ____ is required
cholesterol UV light (sunshine) is required
The primary role of the B vitamins is to act as
coenzymes in a number of metabolic processes
Lipoic acid functions to
couple acyl-group transfer and electron transfer during oxidation and decarboxylation of -keto acids
The B vitamins can function in ____ (3: ECS)
energy metabolism cell regeneration synthesis of red blood cells
Thiamine has a central role in ___ metabolism, and especially the metabolism of ___
energy-yielding metabolism, and especially the metabolism of carbohydrates
2 Forms of Vitamin D: D2 aka ___ is the form found in ___ UV irradiation of milk converts __ to ___ has 100% ____ less stable than ____
ergocalciferol Is the form found in milk UV irradiation of milk converts ergosterol (a plant form) into ergocalciferol Has 100% vitamin D activity Less stable than D3 in the body
Fat soluble vitamins (4) & water soluble vitamins (2)
fat soluble (vitamins A, D, E and K) water soluble (vitamins B and C)
Most common vitamin deficiency among pregnant women
folic acid deficiency
Vitamin K is fat soluble: form ___ absorbed & formed into ___ exported into ____ carried in ___ system in ____ to target tissues
form micelles with dietary fats and bile salts absorbed and formed into chylomicrons exported into lymph system carried in circ system in chylomicrons to target tissues
Beta-carotene is from ___ & is a precursor of ____
from plant foods and is a precursor of Vitamin A
Vitamin K is also produced by
gut bacteria in colon ~15% of daily vit K
The fat soluble vitamins are soluble in ___ these vitamins are usually absorbed in ____ that travel through the ____ & into the general blood circulation within the body these fat soluble vitamins, especially A&E are then stored in ____
lipids (fats). These vitamins are usually absorbed in fat globules (called chylomicrons) that travel through the lymphatic system of the small intestines and into the general blood circulation within the body. These fat soluble vitamins, especially vitamins A and E, are then stored in body tissues.
The major function of Vitamin D is to
maintain serum Ca2+ at 2.5 mM, and to correct this if levels decrease.
Most common disease of vitamin A deficiency
night blindness
Vitamin K deficiency: defining deficiency: Plasma prothrombin levels: Clotting assay
normal K: 11-13 seconds to clot deficient K: > 25 seconds to clot
Vitamin D works via ___ VDR controls expression of ____
nuclear receptor transcription factor Vitamin D receptor (VDR) (Vit A receptor, thyroid hormone receptor) VDR controls expression of target genes (on and off)
Vitamin D deficiency contributes to
osteoporosis
Vitamin E is thought to be an antioxidant and give us protection from
oxidation and reactive oxygen species
The active coenzyme form of B6 is
pyridoxal phosphate (PLP) which is synthesized in the intestine from all three forms
VitaminB6 is used to collectively represent 3 compounds: Structurally they are ____
pyridoxine, pyridoxal, & pyridoxine structurally they are pyridine derivatives
Vit K takes and modifies the glutamic acid residues by adding an ____ in ____ by adding that extra carboxyl group, prothrombin will ____
residues by adding an extra carboxyl to them in prothrombin. By adding that extra caroxyl group, prothrombin will bind to calcium where it wouldn't bind to calcium before.
Retinol is converted to retinal in the
retina of the eye and is linked to opsin to form rhodopsin, a light-sensitive pigment protein in the rods and cones Vitamin A also affects growth and differentiation
Beta-carotene is the precursor of
retinol
B12 Biochemical Functions: synthesis of ___ from ___ isomerization of ___
synthesis of methionine from homocysteine -thus B12 deficiency results in decreased THF that leads to reduced nucleotide & DNA synthesis isomerization of Methyl malonyl CoA
Vitamin D is a hormone that we CAN ____
synthesize
Although vitamins and minerals do not contain calories, and thus do not directly provide energy, the body is unable to ____
the body is unable to generate energy from macronutrients without them
If you don't have vitamin K, prothrombin does not get held to the ___ & you ___
the site of the wound and you bleed to death. B/c prothrombin gets activated later and converts fibronogen into fibrin, which makes the clot.
Thiamine: The active form of the coenzyme, _____ is synthesized by an enzymatic transfer of a pyrophosphate group from ATP to thiamine
thiamine pyrophosphate (thiamine diphosphate, TPP), is synthesized by an enzymatic transfer of a pyrophosphate group from ATP to thiamine).
Retinal functions: (4: VSBI)
vision sexual reproduction bone health immune function
Retinol functions: (4: VSBI)
vision sexual reproduction bone health immune function
Active coenzymes of riboflavin: 2 (FF) active forms are formed in the ___&___
• FMN: Flavin mononucleotide • FAD: Flavin adenine dinucleotide FAD = FMN + AMP Active forms are formed in the intestine and liver.
Pyridoxine: causes of deficiency (2: IO)
• Isoniazid: Anti tuberculosis drug which inhibits pyridoxal phosphate formation. • Oral Contraceptive Pills: Binds to pyridoxal phosphate and inactivate it
B6 Deficiency Manifestation (3: NDH)
• Neurological Manifestation: Convulsions and Demyelination of the nerves • Dermatological Manifestation: Pellagra because Niacin is not formed from Tryptophan. • Hematological Manifestation: Hypochromic Microcytic Anemia due to inhibition of Heme synthesis.
Riboflavin: causes of deficiency (3: PCP)
• Phototherapy: Riboflavin being light sensitive gets destroyed. • Chronic Alcoholics: • Pregnancy and Lactation: There is increased demand of Riboflavin.