This presentation contains topic related to
CHOLESTEROL, CHOLESTEROL METABOLISM & CHOLESTEROL BIOSYNTHESIS.
Books referred: https://www.amazon.in/Biochemistry-2019-Satyanarayana-Satyanarayana-Author/dp/B07WGHCTKZ/ref=sr_1_1?dchild=1&qid=1591114482&refinements=p_27%3AU+Satyanarayana&s=books&sr=1-1
De novo synthesis of fatty acids (Biosynthesis of fatty acids)Ashok Katta
Synthesis of fatty acids in the body. Detailed pathway for de novo synthesis of fatty acids in the body including its energetic and regulation. also cover Multienzyme complex
explains the palmitate synthesis- which is most common FA stored in Adipose tissue , elongation system and Desaturation system, compares oxidation with synthesis.
Formation and utilization of ketone bodies; ketoacidosisJinal Tandel
Formation and utilization of ketone bodies is part of lipid metabolism. After completion of this topic one can understand about Ketogenesis, utilization of Ketone bodies and ketoacidosis
De novo synthesis of fatty acids (Biosynthesis of fatty acids)Ashok Katta
Synthesis of fatty acids in the body. Detailed pathway for de novo synthesis of fatty acids in the body including its energetic and regulation. also cover Multienzyme complex
explains the palmitate synthesis- which is most common FA stored in Adipose tissue , elongation system and Desaturation system, compares oxidation with synthesis.
Formation and utilization of ketone bodies; ketoacidosisJinal Tandel
Formation and utilization of ketone bodies is part of lipid metabolism. After completion of this topic one can understand about Ketogenesis, utilization of Ketone bodies and ketoacidosis
Lipid metabolism entails the oxidation of fatty acids to either generate energy or synthesize new lipids from smaller constituent molecules. Lipid metabolism is associated with carbohydrate metabolism, as products of glucose (such as acetyl CoA) can be converted into lipids.
cholesterol introduction , synthesis , degradation and functions.
different intermediate products , biochemical importance, fate of cholesterol: synthesis of bile acids (primary and secondary ) , synthesis of vitamin D and different steroid hormones
clinical significance of cholesterol: Hypercholesterolemia ANd hypocholesterolemia normal ranges and so on
Lipid metabolism entails the oxidation of fatty acids to either generate energy or synthesize new lipids from smaller constituent molecules. Lipid metabolism is associated with carbohydrate metabolism, as products of glucose (such as acetyl CoA) can be converted into lipids.
cholesterol introduction , synthesis , degradation and functions.
different intermediate products , biochemical importance, fate of cholesterol: synthesis of bile acids (primary and secondary ) , synthesis of vitamin D and different steroid hormones
clinical significance of cholesterol: Hypercholesterolemia ANd hypocholesterolemia normal ranges and so on
Cholesterol Biosynthesis and catabolism for MBBS, Lab. MEd. BDS.pptxRajendra Dev Bhatt
Cholesterol is found exclusively in animals, hence it is often called as animal sterol.
The total body content of cholesterol in an
adult man weighing 70 kg is about 140 g i.e., around 2 g/kg body weight.
The level of cholesterol in blood is related to the development of atherosclerosis & MI.
the slides aim at providing explanations on cholesterol biosynthesis, regulations, functions of cholesterol, and their consequences. facts about lipoproteins have also been included. enjoy the reading
prepared by Asangalwisye Deo
St. john's University of Tanzania
Triacylglycerol and compound lipid metabolismDipesh Tamrakar
Biosynthesis and metabolic regulation of triglyceride and other compound lipids: glycerophospholipids, sphingophospholipids, ether glycerolipids and glycolipids
Steroids, Classification of Steroids, Cholesterol, Testosterone, Estrogen, Progesterone, Aldosterone, Significance, Biosynthesis, Skeleton structure, History, Bile acids, Cardiac Glycosides, Steroid hormones, Saponins, Mode of Action, Tests of steroids, Sterol, Adrenocorticosteroids, Glucocorticoids, Cortisol, Hydrocortisone, Prednisolone, Mineralocorticoids, Steroid Contraceptives, Androgens, Vitamin D2&D3, Cardenolides
All rights of images and videos are reserved to their rightful owners.
Citric acid is a versatile organic acid found in many fruits, especially citrus fruits like lemons, oranges, limes, and grapefruits. Its chemical formula is C6H8O7, and it's classified as a weak acid. Citric acid has a wide range of applications, from food and beverage production to household cleaning and skincare. In this comprehensive description, I'll delve into its properties, uses, production methods, health effects, and environmental impact.
*1. Properties of Citric Acid:*
Citric acid appears as a white crystalline powder or granules. It's odorless and has a tart, sour taste. It's highly soluble in water, making it easy to incorporate into various products. Citric acid is stable at room temperature but decomposes at higher temperatures, losing its acidic properties. It's a chelating agent, meaning it can bind to metal ions, making it useful in certain industrial processes and household cleaners.
*2. Sources of Citric Acid:*
While citric acid occurs naturally in citrus fruits, it's also produced commercially through microbial fermentation, primarily using strains of the fungus Aspergillus niger. This method allows for large-scale production of citric acid to meet the demand in various industries. Additionally, it can be synthesized chemically, although this method is less common due to higher production costs and environmental concerns.
*3. Uses of Citric Acid:*
*- Food and Beverage Industry:* Citric acid is widely used as a flavoring agent, acidity regulator, and preservative in the food and beverage industry. It enhances the flavor of many products and provides a tart taste in sodas, candies, jams, and preserves. It also acts as a preservative, extending the shelf life of packaged foods and preventing discoloration in fruits and vegetables.
*- Pharmaceutical Industry:* Citric acid is used in pharmaceuticals as a pH regulator, excipient in tablets and capsules, and as a flavoring agent in syrups and liquid medications.
*- Cleaning Products:* Due to its chelating properties, citric acid is used in household cleaning products such as descalers, bathroom cleaners, and dishwashing detergents. It effectively removes mineral deposits and stains without the need for harsh chemicals.
*- Cosmetics and Personal Care:* Citric acid is found in skincare products like exfoliating scrubs, facial peels, and anti-aging creams. It helps to promote skin renewal by gently removing dead skin cells and promoting collagen production.
*- Industrial Applications:* Citric acid is used in various industrial processes, including water softening, metal cleaning, and the production of detergents and surfactants.
*4. Production Methods:*
*- Microbial Fermentation:* This is the most common method for commercial production of citric acid. It involves fermenting glucose or sucrose-containing substrates with strains of Aspergillus niger in large-scale bioreactors. The fungus produces citric acid as a byproduct of its metabolism, which is then extracted and purified.
*- C
Citric acid is a versatile organic acid found in many fruits, especially citrus fruits like lemons, oranges, limes, and grapefruits. Its chemical formula is C6H8O7, and it's classified as a weak acid. Citric acid has a wide range of applications, from food and beverage production to household cleaning and skincare. In this comprehensive description, I'll delve into its properties, uses, production methods, health effects, and environmental impact.
*1. Properties of Citric Acid:*
Citric acid appears as a white crystalline powder or granules. It's odorless and has a tart, sour taste. It's highly soluble in water, making it easy to incorporate into various products. Citric acid is stable at room temperature but decomposes at higher temperatures, losing its acidic properties. It's a chelating agent, meaning it can bind to metal ions, making it useful in certain industrial processes and household cleaners.
*2. Sources of Citric Acid:*
While citric acid occurs naturally in citrus fruits, it's also produced commercially through microbial fermentation, primarily using strains of the fungus Aspergillus niger. This method allows for large-scale production of citric acid to meet the demand in various industries. Additionally, it can be synthesized chemically, although this method is less common due to higher production costs and environmental concerns.
*3. Uses of Citric Acid:*
*- Food and Beverage Industry:* Citric acid is widely used as a flavoring agent, acidity regulator, and preservative in the food and beverage industry. It enhances the flavor of many products and provides a tart taste in sodas, candies, jams, and preserves. It also acts as a preservative, extending the shelf life of packaged foods and preventing discoloration in fruits and vegetables.
*- Pharmaceutical Industry:* Citric acid is used in pharmaceuticals as a pH regulator, excipient in tablets and capsules, and as a flavoring agent in syrups and liquid medications.
*- Cleaning Products:* Due to its chelating properties, citric acid is used in household cleaning products such as descalers, bathroom cleaners, and dishwashing detergents. It effectively removes mineral deposits and stains without the need for harsh chemicals.
*- Cosmetics and Personal Care:* Citric acid is found in skincare products like exfoliating scrubs, facial peels, and anti-aging creams. It helps to promote skin renewal by gently removing dead skin cells and promoting collagen production.
*- Industrial Applications:* Citric acid is used in various industrial processes, including water softening, metal cleaning, and the production of detergents and surfactants.
*4. Production Methods:*
*- Microbial Fermentation:* This is the most common method for commercial production of citric acid. It involves fermenting glucose or sucrose-containing substrates with strains of Aspergillus niger in large-scale bioreactors. The fungus produces citric acid as a byproduct of its metabolism, which is then extracted and purified.
*- C
Catabolism of Purine Nucleotides | Hyperuricemia | Goutkiransharma204
This PPT contains topic on Catabolism of purine nucleotides, Hyperuricemia and Gout.
Book referred: https://www.amazon.in/BIOCHEMISTRY-SATYANARAYANA-5TH-2017/dp/B073Y7XGH4
Biosynthesis of Purine and Pyrimidine Nucleotideskiransharma204
This PPT contains topic on Biosynthesis of Purine and Pyrimidine Nucleotides.
Book referred: https://www.amazon.in/BIOCHEMISTRY-SATYANARAYANA-5TH-2017/dp/B073Y7XGH4
Catabolism of Heme | Jaundice | Hyperbilirubinemiakiransharma204
This PPT contain topics on Catabolism of heme; hyperbilirubinemia and jaundice
Books referred: https://www.amazon.in/Biochemistry-2019-Satyanarayana-Satyanarayana-Author/dp/B07WGHCTKZ/ref=sr_1_1?dchild=1&qid=1592209115&refinements=p_27%3AU+Satyanarayana&s=books&sr=1-1
This PPT contains topic on Serotonin pathway, degradations of Serotonin, functions of Serotonin, Melatonin pathway and functions of Melatonin.
Book referred: https://www.amazon.in/Biochemistry-2019-Satyanarayana-Satyanarayana-Author/dp/B07WGHCTKZ/ref=sr_1_1?dchild=1&qid=1592209115&refinements=p_27%3AU+Satyanarayana&s=books&sr=1-1
Catabolism of Phenylalanine and Tyrosine | Disorders Of Tyrosine Metabolismkiransharma204
This PPT contains topic related to Catabolism of Phenylalanine and Tyrosine, Disorders Of Tyrosine Metabolism and metabolic disorders like Phenyketonuria, Albinism, Alkaptonuria and Tyrosinemia.
Books referred: https://www.amazon.in/s?k=satyanarayan+biochemistry&i=stripbooks&crid=2UMKA76J0R8WC&sprefix=satya%2Cstripbooks%2C456&ref=nb_sb_ss_i_2_5
Urea Cycle | Energetics of Urea Cycle | Regulation of Urea Cycle | Metabolic ...kiransharma204
This PPT contains topics related to Urea Cycle, Energetics of Urea Cycle, Regulation of Urea Cycle, Metabolic disorder of Urea Cycle & Clinical Importance.
Books referred: https://www.amazon.in/Biochemistry-2019-Satyanarayana-Satyanarayana-Author/dp/B07WGHCTKZ/ref=sr_1_1?crid=3FLX88MWT4Y30&dchild=1&keywords=satyanarayan+biochemistry&qid=1591701828&s=books&sprefix=satyanarayan+%2Cstripbooks%2C387&sr=1-1
This PPT is on Amino acid metabolism. And the topics covered under this ppt are Transamination, deamination
Book referred: https://www.amazon.in/Biochemistry-2019-Satyanarayana-Satyanarayana-Author/dp/B07WGHCTKZ/ref=sr_1_1?dchild=1&qid=1591608419&refinements=p_27%3AU+Satyanarayana&s=books&sr=1-1
Disorders of lipid metabolism | Hypercholesterolemia | Atherosclerosis | Fatt...kiransharma204
This ppt contains details on Disorders of lipid metabolism, Hypercholesterolemia, Atherosclerosis, Fatty liver & Obesity.
Book referred: https://www.amazon.in/Biochemistry-2019-Satyanarayana-Satyanarayana-Author/dp/B07WGHCTKZ/ref=sr_1_1?dchild=1&qid=1591592368&refinements=p_27%3AU+Satyanarayana&s=books&sr=1-1
De Novo Synthesis of fatty acids | Biosynthesis Of Fatty Acids |kiransharma204
This presentation contains De Novo Synthesis of fatty acids & Regulation of fatty acid synthesis
Books referred: https://www.amazon.in/Biochemistry-2019-Satyanarayana-Satyanarayana-Author/dp/B07WGHCTKZ/ref=sr_1_1?dchild=1&keywords=satyanarayan+books+biochemistry&qid=1590834248&sr=8-1
Diabetes Mellitus | Types of Diabetes Mellitus kiransharma204
This presentation contains content on Diabetes Mellitus, Types of Diabetes Mellitus especially on Type 1 DM, Type 2 DM, Gestational DM and Other specific DM
Video link: https://www.youtube.com/watch?v=OpTpZnCpHz0
Insulin | Discovery of Insulin | Structure of insulin | Biosynthesis of Insul...kiransharma204
This presentation contains content on Discovery of Insulin, Structure of insulin, Biosynthesis of Insulin, Regulation of Insulin, Degradation of Insulin, Metabolic Effect of insulin & Mechanism of action of insulin
Video link: https://www.youtube.com/watch?v=Qxb5AcPwV3k&t=14s
This PPT contains HMP Shunt, Reactions of the pathway i.e. Oxidative & Non-oxidative. Glucose-6-Phosphate dehydrogenase (G6PD) deficiency, Regulation of Pathway, Significance of HMP shunt
This PPT contains content of Gluconeogenesis, Steps involved in Gluconeogenesis, (Gluconeogenesis from Pyruvate, Gluconeogenesis from lactate, Gluconeogenesis from amino acids, Gluconeogenesis from glycerol, Gluconeogenesis from Propionate), Regulation and significance of Gluconeogenesis
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
263778731218 Abortion Clinic /Pills In Harare ,sisternakatoto
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Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
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ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
Acute scrotum is a general term referring to an emergency condition affecting the contents or the wall of the scrotum.
There are a number of conditions that present acutely, predominantly with pain and/or swelling
A careful and detailed history and examination, and in some cases, investigations allow differentiation between these diagnoses. A prompt diagnosis is essential as the patient may require urgent surgical intervention
Testicular torsion refers to twisting of the spermatic cord, causing ischaemia of the testicle.
Testicular torsion results from inadequate fixation of the testis to the tunica vaginalis producing ischemia from reduced arterial inflow and venous outflow obstruction.
The prevalence of testicular torsion in adult patients hospitalized with acute scrotal pain is approximately 25 to 50 percent
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
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
2. CHOLESTEROL
• Cholesterol is found in animals, therefore it is
called as animal sterol.
• Total content of cholesterol in an adult is• Total content of cholesterol in an adult is
around 2 g/kg body weight.
• It is amphipathic in nature, (hydrophilic and
hydrophobic).
3. Functions of cholesterol
1. Structural component of cell membrane.
2. Precursor for the synthesis of all other steroids in
the body. E.g. steroid hormones, vitamin D and
bile acids.bile acids.
3. Essential ingredient in the structure of
lipoproteins.
4. Fatty acids are transported to liver as cholesteryl
esters for oxidation.
4. CHOLESTEROL BIOSYNTHESIS
• All tissues can produce cholesterol. But the largest is produced by:
– Liver (50%), Intestine (15%), Skin, Adrenal Cortex, Reproductive
Tissue etc.
• Enzymes are found: In the cytosol and microsomal fractions of the cell.
• Acetate of acetyl CoA provides : carbon atoms.• Acetate of acetyl CoA provides : carbon atoms.
• The reducing equivalents are supplied by NADPH while ATP provides
energy.
• Requirement for the production of 1 mole of cholesterol:
– 18 moles of acetyl CoA
– 36 moles of ATP
– 16 moles of NADPH.
5. 5 stages of synthesis of cholesterol
1. Synthesis of HMG CoA
2. Formation of mevalonate (6C)
3. Production of isoprenoid units (5C)3. Production of isoprenoid units (5C)
4. Synthesis of squalene (30C)
5. Conversion of squalene to cholesterol (27C).
6. Synthesis of β-hydroxy β -methylglutaryl CoA (HMG
CoA):
• Two moles of acetyl CoA condense to form
acetoacetyl CoA. Another molecule of acetyl CoA is
then added to produce HMG CoA.
Stage 1
then added to produce HMG CoA.
• Cholesterol synthesis occurs in cytosol.
• Two isoenzymes of HMG CoA synthase are known.
Cytosomal enzyme: for cholesterol synthesis
Mitochondrial enzyme: for ketone body synthesis
7.
8. Formation of mevalonate:
• HMG CoA reductase is the rate limiting
enzyme in cholesterol biosynthesis.
• This enzyme is present in endoplasmic
Stage 2
• This enzyme is present in endoplasmic
reticulum and catalyses the reduction of HMG
CoA to mevalonate.
• The reducing equivalents are supplied by
NADPH.
9.
10. Production of isoprenoid units:
• 3 step reaction catalysed by kinases, mevalonate is
converted to 3-phospho 5 pyrophosphomevalonate
which on decarboxylation forms isopentenyl
pyrophosphate (IPP).
Stage 3
pyrophosphate (IPP).
• The latter isomerizes to dimethylallyl pyrophosphate
(DPP).
• Both IPP and DPP are 5-carbon isoprenoid units.
11.
12. Synthesis of squalene:
• IPP and DPP condense to produce a 10-carbon
geranyl pyrophosphate (GPP).
• Another molecule of IPP condenses with GPP
Stage 4
• Another molecule of IPP condenses with GPP
to form a 15-carbon farnesyl pyrophosphate
(FPP).
• Two units of farnesyl pyrophosphate unite and
get reduced to produce a 30-carbon squalene.
13.
14. Conversion of squalene to cholesterol:
• Squalene undergoes hydroxylation and cyclization utilizing
O2 and NADPH and gets converted to lanosterol.
• The formation of cholesterol from lanosterol is a multistep
process with a series of about 19 enzymatic reactions.
• The following are the most important reactions:
– Reducing the carbon atoms from 30 to 27.
Stage 5
– Reducing the carbon atoms from 30 to 27.
– Removal of two methyl groups from C4 and one methyl group
from C14.
– Shift of double bond from C8 to C5.
– Reduction in the double bond present between C24 and C25.
15. • 14- Desmethyl lanosterol, zymosterol,
cholestadienol and desmosterol: Intermediates
in the cholesterol biosynthesis.in the cholesterol biosynthesis.
• The penultimate product is 7-dehydrocholesterol
which, on reduction, finally yields cholesterol.
18. Synthesis of bile acids from Cholesterol
The bile acids possess 24 carbon atoms, 2 or 3
hydroxyl groups in the steroid nucleus and a side
chain ending in carboxyl group.
The bile acids are amphipathic in nature.The bile acids are amphipathic in nature.
They serve as emulsifying agents in the intestine
and helps in the digestion and absorption of
lipids.
The synthesis takes place in the liver.
19. • The step catalysed by 7 α-hydroxylase is the rate
limiting reaction. And the reaction is inhibited by bile
acids.
• Cholic acid and chenodeoxycholic acid are the primary
bile acids.bile acids.
• On conjugation with glycine or taurine, conjugated bile
acids (glycocholic acid, taurocholic acid etc.) are
formed .
• In the bile, the conjugated bile acids exist as sodium
and potassium salts which are known as bile salts.
20. In the intestine, a portion of primary bile acids
undergoes deconjugation and dehydroxylation
to form secondary bile acids (deoxycholic acid
and lithocholic acid).and lithocholic acid).
These reactions are catalysed by bacterial
enzymes in the intestine.
21.
22. Synthesis of steroid hormones from
cholesterol
Cholesterol is the precursor for the synthesis of
all the five classes of steroid hormones
(a) Glucocorticoids (e.g. cortisol)
(b) Mineralocorticoids (e.g. aldosterone)(b) Mineralocorticoids (e.g. aldosterone)
(c) Progestins (e.g. progesterone)
(d) Androgens (e.g. testosterone)
(e) Estrogens (e.g. estradiol).
26. Synthesis of vitamin D
7-Dehydrocholesterol, an intermediate in the
synthesis of cholesterol, is converted to
cholecalciferol (vitamin D3) by ultraviolet rays
in the skin.in the skin.