1. Vitamins are organic molecules that serve as cofactors for enzyme reactions and must be obtained through diet as they cannot be synthesized by the body.
2. Vitamins are classified as either water-soluble or fat-soluble, with water-soluble vitamins including all B vitamins and vitamin C, and fat-soluble vitamins being vitamins A, D, E, and K.
3. Each vitamin has a specific biochemical function, such as vitamin C serving as an antioxidant and cofactor for collagen synthesis, vitamin B12 acting as a cofactor for fatty acid and amino acid metabolism, and vitamin K being required for blood clotting through gamma-carboxylation of glutamate residues.
Introduction, Classification of Vitamins, Fat –Soluble Vitamins-) Vitamin A ,Biochemical Function of Vitamin A, Deficiency of Vitamin A, Vitamin D ,Vitamin E, Deficiency and Role of Vit.E , Vitamin K, Water-Soluble Vitamins, Thiamine, ) Riboflavin , Nicotinic Acid, Pantothenic acid , Pyridoxine , Biotin, Deficiency of folic acid, Cyanocobalamin, structure and deficiency of co-enzyme B12 , Lipoic acid, Non B-Complex, Ascorbic acid , benifites of vit. C, CO-ENZYMES,
Vitamins as coenzymes, different forms and deficiency disorders Lovnish Thakur
Vitamins are organic compounds which are needed in small quantities to sustain life.
Get from food, because the human body either does not produce enough of them, or none at all
this presentation is about Vitamin B6 which include structure , biochemical function , biochemical reaction, effect of deficiency of vitamin B6, Toxicity and function of Vitamin B6.
Introduction, Classification of Vitamins, Fat –Soluble Vitamins-) Vitamin A ,Biochemical Function of Vitamin A, Deficiency of Vitamin A, Vitamin D ,Vitamin E, Deficiency and Role of Vit.E , Vitamin K, Water-Soluble Vitamins, Thiamine, ) Riboflavin , Nicotinic Acid, Pantothenic acid , Pyridoxine , Biotin, Deficiency of folic acid, Cyanocobalamin, structure and deficiency of co-enzyme B12 , Lipoic acid, Non B-Complex, Ascorbic acid , benifites of vit. C, CO-ENZYMES,
Vitamins as coenzymes, different forms and deficiency disorders Lovnish Thakur
Vitamins are organic compounds which are needed in small quantities to sustain life.
Get from food, because the human body either does not produce enough of them, or none at all
this presentation is about Vitamin B6 which include structure , biochemical function , biochemical reaction, effect of deficiency of vitamin B6, Toxicity and function of Vitamin B6.
Small amounts of vitamins are required in the diet to promote growth, reproduction, and health. Vitamins A, D, E, and K are called the fat-soluble vitamins, because they are soluble in organic solvents and are absorbed and transported in a manner similar to that of fats.
Fatty acid oxidation
Types of fatty acid oxidation
Overview of fatty acid oxidation
Beta-Oxidation of fatty acid
Steps in Beta-Oxidation of fatty acid
Stoichiometry of Beta oxidation
Reference
Coenzyme - Introduction, Definition, Examples for coenzyme, reaction catalysed by coenzyme, Types of coenzymes - cosubstrate and prosthetic group coenzymes, second type of classification of coenzyme- hydrogen group transfer , other than hydrogen group transfer.
LHD is an enzyme which is width sprid through the body tissue has an important role in the conversion of pyrovate into lactate within the tissue when ever there is hypoxia in the body
Small amounts of vitamins are required in the diet to promote growth, reproduction, and health. Vitamins A, D, E, and K are called the fat-soluble vitamins, because they are soluble in organic solvents and are absorbed and transported in a manner similar to that of fats.
Fatty acid oxidation
Types of fatty acid oxidation
Overview of fatty acid oxidation
Beta-Oxidation of fatty acid
Steps in Beta-Oxidation of fatty acid
Stoichiometry of Beta oxidation
Reference
Coenzyme - Introduction, Definition, Examples for coenzyme, reaction catalysed by coenzyme, Types of coenzymes - cosubstrate and prosthetic group coenzymes, second type of classification of coenzyme- hydrogen group transfer , other than hydrogen group transfer.
LHD is an enzyme which is width sprid through the body tissue has an important role in the conversion of pyrovate into lactate within the tissue when ever there is hypoxia in the body
briefly describe enzyme and coenzyme and its role in many orders. Consist of enzyme nomenclature, enzyme part: prosthetic group, metalions, cofactors, and secondary substrate. Describe inhibition action.
Enzyme inhibition is explained with its kinetics, animations showing mechanism of inhibitors action, examples of inhibitors are explained in detail with Enzyme inhibited.
by Dr. N. Sivaranjani, MD
Thiamine (vitamin B1) and biochemical aspects of beriberirohini sane
A comprehensive presentation on Thiamine and biochemical aspects of Beriberi for MBBS, BDS, B Pham and Biotechnology students to facilitate easy leaning.
Avrupa Parlamentosu ve Konseyi'nin Gıda Yasasıyla İlgili Genel İlke ve Şartla...Ülger Ahmet
Avrupa Parlamentosu ve Konseyi'nin Gıda Yasasıyla İlgili Genel İlke ve Şartları Belirleyen, Avrupa Gıda Güvenliği İdaresi' ni Kuran ve Gıda Güvenliği Konularıyla İlgili İşlemleri Belirleyen 28 Ocak 2002 Tarih ve (EC)178/2002 Sayılı Tüzüğü
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
263778731218 Abortion Clinic /Pills In Harare ,sisternakatoto
263778731218 Abortion Clinic /Pills In Harare ,ABORTION WOMEN’S CLINIC +27730423979 IN women clinic we believe that every woman should be able to make choices in her pregnancy. Our job is to provide compassionate care, safety,affordable and confidential services. That’s why we have won the trust from all generations of women all over the world. we use non surgical method(Abortion pills) to terminate…Dr.LISA +27730423979women Clinic is committed to providing the highest quality of obstetrical and gynecological care to women of all ages. Our dedicated staff aim to treat each patient and her health concerns with compassion and respect.Our dedicated group ABORTION WOMEN’S CLINIC +27730423979 IN women clinic we believe that every woman should be able to make choices in her pregnancy. Our job is to provide compassionate care, safety,affordable and confidential services. That’s why we have won the trust from all generations of women all over the world. we use non surgical method(Abortion pills) to terminate…Dr.LISA +27730423979women Clinic is committed to providing the highest quality of obstetrical and gynecological care to women of all ages. Our dedicated staff aim to treat each patient and her health concerns with compassion and respect.Our dedicated group of receptionists, nurses, and physicians have worked together as a teamof receptionists, nurses, and physicians have worked together as a team wwww.lisywomensclinic.co.za/
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
Knee anatomy and clinical tests 2024.pdfvimalpl1234
This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
Follow us on: Pinterest
Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
1. Introduction to Vitamins
Vitamins are organic molecules that perform a wide variety of functions in the body. The
most prominent function is as cofactors for enzymatic reactions. Vitamins generally cannot be
synthesized by mammalian cells and, therefore, must be supplied in the diet. The vitamins are
classified into two groups.
Water Soluble Vitamins Fat Soluble Vitamins
• Thiamin (B1)
• Riboflavin (B2)
• Niacin (B3)
• Cobalamin (B12)
• Pantothenic Acid (B5)
• Pyridoxal, Pyridoxamine,
Pyridoxine (B6)
• Biotin Folic Acid
• Ascorbic Acid
All letter vitamins except
Vitamin C
• Vitamin A
• Vitamin D
• Vitamin E
• Vitamin K
1. Vitamins serve as cofactors in enzyme catalysis
2. The cofactor nay be bound to the enzyme or free
3. When bound, the cofactor becomes the prosthetic group
of the enzyme
4. enzyme + cofactor is called the ‘Holoenzyme’
enzyme alone is called the ‘Apoenzyme
Thiamin (Vitamin B1)
1. Thiamin is also known as vitamin B1 .
It is a derivative of substituted pyrimidine and a thiazole, linked by a methylene
bridge.
2. Its biologically active form is thiamin pyrophosphate, TPP
TPP is formed in the brain and liver by the enzyme, Thiamin diphosphotransferase.
2. Coenzyme Form: Thiamin pyrophosphate
3. TPP serves as a cofactor for the pyruvate and α-ketoglutarate dehydrogenase
reactions as well as the transketolase catalyzed reactions of the pentose phosphate
pathway.
4. Deficiency of thiamin leads to neurological conditions like ataxia, mental confusion,
peripheral neuropathy and a disease known as Beriberi
Riboflavin (Vitamin B2)
Riboflavin structure
1. Riboflavin is also known as vitamin B2.
2. The coenzymes forms of riboflavin are, flavin mononucleotide (FMN)
and flavin adenine inucleotide (FAD).
3. The enzymes that require FMN or FAD as cofactors are termed
flavoproteins.
4. Flavoproteins are involved in a wide range of redox reactions, e.g.
succinate dehydrogenase and xanthine oxidase.
5. The reduced forms of FMN and FAD are formed, FMNH2 and FADH2,
respectively.
3. Structure of FAD
Nitrogens 1 & 5 carry hydrogens in FADH2
Coenzyme Function:
1. Riboflavin acts as an integral component of two coenzymes: FAD
(flavin adenine dinucleotide) and FMN (flavin mononucleotide).
2. FAD and FMN are known as flavins since they are derived from
riboflavin. FMN and FAD serve as cofactors for a family of proteins
called flavoenzymes.
4. 3. Flavoenzymes catalyze a wide range of biochemical reactions,
typically redox reactions. They are key elements in cellular
respiration. In cellular respiration, FAD and FMN act as intermediate
hydrogen acceptors in the mitochondrial electron transport chain,
accepting hydrogens derived from foodstuffs, and transferring
electrons to the cytochrome system. During this process, ATP is
released (2 moles of ATP per mole of FADH2).
Clinical Significances of Flavin Deficiency
6. Riboflavin deficiency is often seen in chronic alcoholics due to their poor
dietetic habits.
7. Symptoms associated with riboflavin deficiency include, glossitis, seborrhea,
angular stomatitis.
8. Riboflavin is an orange powder, and water solutions have intense greenish
yellow fluorescence.
9. Riboflavin, is found naturally in the food we eat. Sources of riboflavin include
organ meats (liver, kidney, and heart) and certain plants such as almonds,
mushrooms, whole grain, soybeans, and green leafy vegetables.
Biotin (Vitamin H or B7)
1. Biotin, also known as vitamin H or B7.
2. It is a water-soluble B-complex vitamin which is composed of an ureido
(tetrahydroimidazalone) ring fused with a tetrahydrothiophene ring. A valeric acid
substituent is attached to one of the carbon atoms of the tetrahydrothiophene ring.
3. Biotin is important in the catalysis of essential metabolic reactions of (a) biosynthesis
of fatty acids, (b) gluconeogenesis, and (c) metabolism of Leucine.
4. Biotin is found in numerous foods and also is synthesized by intestinal bacteria and as
such deficiencies of the vitamin are rare. Deficiencies are generally seen only after long
antibiotic therapies which prevent intestinal absorption of the biotin.
5. Biotin is the cofactor (no coenzyme form, involved as it is) required for enzymes that
are involved in carboxylation reactions, e.g. Acetyl-CoA carboxylase and pyruvate
carboxylase.
5. Vitamin B6
Vitamin B6 is the name given to three related pyrimidine derivatives:
Pyridoxine Pyridoxal Pyridoxamine
1. Pyridoxine, pyridoxal and pyridoxamine are collectively known as vitamin B6
2. All three compounds are efficiently converted in the body to the coenzyme form
of vitamin B6, pyridoxal phosphate (PALP)
3. This conversion is catalyzed by the ATP requiring enzyme, pyridoxal kinase.
Coenzyme form of Vit-B6: Pyridoxal Phosphate
5. Pyridoxal phosphate functions as a cofactor for transamination, deacrboxylation and
recemase reactions
6. All these reactions involve the formation of a Schiff’s base linkage (-N=CH-)
The phenyl ring with positive charge on the nitrogen atom, delocalized over the ring
stabilizes the Schiff’s base.
7.. Deficiencies of vitamin B6 are rare and usually are related to an overall deficiency of
all the B-complex vitamins.
8. .Isoniazid and penicillamine (used to treat rheumatoid arthritis and cystinurias) are two
drugs that complex with pyridoxal and pyridoxal phosphate resulting in a deficiency in
this vitamin.
Niacin (Vitamin B3)
Nicotinamide Nicotinic Acid
6. 1. Niacin (nicotinic acid and nicotinamide) is also known as vitamin B3.
2. The coenzyme forms of niacin are nicotinamide adenine dinucleotide (NAD+
) and
nicotinamide adenine dinucleotide phosphate (NADP+
).
3. Both NAD+
and NADP+
function as cofactors for numerous
dehydrogenase, e.g.,
lactate and malate dehydrogenases.
Structure of NAD+
4. In the oxidized form of NAD (NAD+
) the pyridine ring is positively charged
Due to the delocalization of the positive charge on the nitrogen atom.
5. In the reduced form, this positive charge is removed and the C-atom at
Position 4 gains a H-atom forming –CH2 group as shown in the insert in the
box insert. The -OH phosphorylated in NADP+
is indicated by the red arrow.
6. Difficiency of Niacin leads to glossitis of the tongue, dermatitis, weight loss,
diarrhea, depression and dementia. When these symptoms are severe, the
condition is known as pellagra.
Biochemical Functions:
7. The coenzymes, NAD+
and NADP+
are involved in a variety of oxidation-reduction
reactions. They accept electrons in the form of hydride ion , H
-
(hydrogen atom + an
electron).
The reduction occurs in the pyridine ring, resulting in the neutralization of the
Positive charge. The overall reaction can be written as:
7. AH2 + NAD+
A + NADH + H+
(reduced substrate) (oxidized substrate)
NADP+
functions exactly like NAD+
There are nearly 40 different oxidoreductases which use either NAD+
or
NADP+
as cofactors. Some are specific to only NAD+
or only NADP+
,
while some use either one of them. These coenzymes are loosely bound to
enzymes and can be separated from the enzymes by dialysis.
In addition to its role in oxido-reduction reactions, NADH acts as carrier of
Reducing equivalents (electrons) from metabolic intermediates and delivers them
To the ETC in mitochondria where they are oxidized to produce ATP. 3 moles of
ATP are produced per mole of NADH oxidized.
While NADH is generally functions as a coenzyme if catabolic reactions, NADPH is
involved in anabolic reactions like the biosynthesis of fatty acids and some reactions of
PPP.
Pantothenic Acid (Vitamin B5)
Pantoic acid β-alanine
1. Pantothenic acid is also known as vitamin B5.
2. Pantothenic acid is formed from β-alanine and pantoic acid.
3. The coenzyme form of Pantothenate is coenzyme A.
8. 4. At least 70 enzymes require CoA for their action.
5. Deficiency of pantothenic acid is extremely rare due to its widespread
distribution in whole grain cereals, legumes and meat.
Coenzyme A
1. Coenzyme A is formed from pantothenic acid and 3 –moles of ATP
In a 4-step reaction.
2. Coenzyme A or CoA has a terminal thiol group which is the reactive part
of the coenzyme. Acyl groups (free fatty acids) are linked to CoA by a
thioester bond (-S-CoA) to give acyl CoA. Thus
Acetate forms Acetyl CoA
CH3-COO-
CH3-CO-S-CoA
Succinate forms Succinyl CoA
-
OOC-CH2CH2-COO- -
OOC-CH2-CH2-CO-S-CoA
Propionatate forms Propionyl CoA
CH3-CH2-COO- CH3-CH2-CO-S-CoA
3. Coenzyme A serves a carrier of activated acetyl or acyl groups as thiol
esters. This function is similar to ATP which acts as a carrier of activated
phosphoryl group (-PO3
2-
). Some of the reactions that involve coenzyme A
are:
CoASH
(a) Pyruvate Acetyl CoA
PDH
CH3-CO-COO- CH3-CO-S-CoA
9. Vitamin B12 Cobalamin
1. Cobalamin is more commonly known as vitamin B12.
2. It is composed of a complex tetrapyrrol ring structure (corrin ring)
and a cobalt ion in the center.
3. Vitamin B12 is synthesized exclusvely by microorganisms and is found in the
liver of animals, bound to proteins.
4. The vitamin must be hydrolyzed from protein in order to be active.
Hydrolysis occurs in the stomach by gastric acids or in the intestines by trypsin
digestion. After absorption, the vitamin is transported to the liver in the blood.
5. The Co2+
ion present at the center of the tetrahydropyrrole ring system is
usually coordinated to one of the following:
a. Cyanide (cyanocobalamine) (B12a)
b. Hydroxyl (hydroxycobalamine) (B12b)
c. Nitrite (nitrocobalamine) (B12c)
6. There are two coenzyme forms of Vitamine B12.
(a) 5-deoxyadenosyl cobalamine: -CN is replaced by 5’-deoxyadenosine
(b) Methylcobalamine: -CN is replaced by methyl group.
7. Biochemical Function: Vitamin B12 is a cofactor for two clinically
significant reactions in the body. In fatty acid synthesis, the enzyme
methylmalonyl-CoA mutase, requires vitamin B12 as a cofactor in the
10. conversion of methylmalonyl-CoA to succinyl-CoA.
The second reaction requiring vitamin B12 catalyzes the conversion of
homocysteine to methionine and is catalyzed by methionine synthase.
Folic Acid (folacin)
Pteridine PABA Glutamate
positions 7 & 8 carry hydrogens in dihydrofolate (DHF)
positions 5, 6, 7, & 8 carry hydrogens in tetrahydrofolate (THF)
1. Folic acid is abundantly found in green leaves (Latin, folium means leaf)
2. It is conjugated molecule consisting of a pteridine ring structure linked
to para-aminobenzoic acid (PABA) that forms pteroic acid, which is
conjugated to a glutamic acid residue.
3. Folic acid is obtained primarily from yeasts and leafy vegetables as well
as animal liver.
4. Animals cannot synthesize PABA nor attach glutamate residues to
pteroic acid, thus, requiring folate intake in the diet.
5. Folic acid is reduced within cells (principally in the liver where it is
stored) to tetrahydrofolate (THF also H4folate) through the action of
dihydrofolate reductase (DHFR), an NADPH-requiring enzyme.
6. The function of THF derivatives is to carry and transfer various forms of
one carbon units during biosynthetic reactions. The one carbon units
are methyl, methylene, methenyl, formyl or formimino groups.
7. Active center of tetrahydrofolate (THF): Note that the N5
position is
the site of attachment of methyl groups, the N10
the site for attachment of
formyl and formimino groups and that both N5
and N10
bridge the
methylene and methenyl groups.
11. 8. These one carbon transfer reactions are required in the biosynthesis of
serine, methionine, glycine, choline and the purine nucleotides and
dTMP.
Clinical Significance of Folate Deficiency
Folate deficiency results in complications nearly identical to those described for
vitamin B12 deficiency. The most pronounced effect of folate deficiency on
cellular processes is upon DNA synthesis.
Ascorbic Acid
Ascorbic Acid
1. Ascorbic acid is more commonly known as vitamin C.
2. Ascorbic acid is derived from glucose via the uronic acid pathway.
3. Ascaorbic acid has no coenzyme form. The active form of vitamin C is
ascorbate acid itself.
4. The main function of ascorbate is as a reducing agent in a number of different
reactions. Vitamin C has the potential to reduce cytochromes a and c of the
respiratory chain as well as molecular oxygen.
5. The most important reaction requiring ascorbate as a cofactor is the
hydroxylation of proline residues in collagen. Vitamin C is, therefore,
required for the maintenance of normal connective tissue as well as for
wound healing since synthesis of connective tissue is the first event in
wound tissue
12. NN
N
N
O
N
N
S S
HO
OH
HO
CH2
Vitamin D 1, 25-dihydroxycholecalciferol Calcium/phosphate metabolism
CHO
Vitamin A 11-cis-retinol Visual Cycle
Lipoic Acid Lipoyl Lysine Acyl Group Transfer
-CH2-CH2-CH2-CH2COO-
HOCH2
CH 3
CH 3
OHO
O
O
PO
-
Co
+
N-C-CH2-CH2-
CH3
CH
CH2
H3C
H3C
CH3
CH3
CH2
CH2-C-NH2
O
H
O
CH2
CH2-C-NH2
O
CH2-C-NH2
OCH3
CH3
H3C
H3C
CH2
CH2
C
NH2
O
H2C
CO
H2N
H2C
CO
H2N
Vitamin B12 Coenzyme B12 (Cobalamin) 1, 2 Prototropic Shift
13. O
Vitamin E α-Tocophoreol Antioxidant
HO
CH3
Vitamin K Phylloquinone γ-Carboxylation of Glutamate
Blood Clotting
O
O