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St. Kitts & Nevis
I'm a physician doctor with an MD degree. My passion for teaching has always been appreciated by students with whom I have shared my knowledge. I'm a passionate teacher of medical biochemistry and would like to share my knowledge about this beautiful subject with all those who is interested to learn to understand the cellular metabolic events and to understand the metabolic disease process. I would like to learn new things by keeping myself updated with current research in the field. Let us share the knowledge each other!!

Wednesday, October 19, 2016

Essential Fructosuria and Hereditary Fructose Intolerance






In this video I have explained about two disorders related with fructose metabolism that is essential fructosuria and hereditary fructose intolerance. Essential fructosuria is due to fructokinase deficiency and hereditary fructose intolerance is due to aldolase B deficiency. Patients with hereditary fructose intolerance will have nausea, vomiting, diarrhea, intolerance to fructose, jaundice, liver damage, kidney damage, convulsion, seizures, coma. Essential fructosuria is asymptomatic condition with only elevated levels of fructose in blood and urine. 

Wednesday, October 12, 2016

One Carbon Metabolism



In this video I have explained about one carbon metabolism reactions and the donors and formation of one carbon derivatives. Tetrahydrofolate (THF) plays a central role in one carbon metabolism. Vitamin B12, B6 and B2 that is cobalamin, pyridoxine and riboflavin, respectively, helps in the formation of one carbon derivatives from THF. One carbon metabolism participates in synthesis of thymidylate monophosphate, C2 and C8 of purine ring, synthesis of glycine from serine and conversion of homocystienine into methionine. 

Why Electrons flow from NADH to O2 in Electron Transport Chain



In this video I have explained the fundamental basis of electron transport chain that is the redox potential of NADH which is a electron donor and O2 which is a final electron acceptor. Electron transport chain which also referred as oxidative phosphorylation or respiratory chain runs with the redox potential difference of 1140 mv between NADH and O2. This drives flow of electrons from NADH to O2 via complex I, CoQ, III, cytochrome C and complex IV. The energy in the flow of electrons helps in pumping of protons across the membrane. 

Pyruvate Dehydrogenase Complex - Regulation



In this video I have explained all the points related to regulation of pyruvate dehydrogenase enzyme complex. Pyruvate dehydrogenase enzyme complex is also written as PDH complex or simple PDC. It has feedback regulation, allosteric modulation, covalent modification mediated by insulin and glucagon. In fasting condition its activity will decrease and in fed condition its activity will increase. NADH, acetyl CoA have a negative effect on PDH, ADP and pyruvate and Ca2+ will have a positive effect on PDH complex.

TCA Cycle - Regulation



In this video I have explained all the points related to regulation of TCA cycle. The main enzyme in regulation of TCA cycle or citric acid or Krebs cycle is isocitrate dehydrogenase. Other enzymes that are regulated are alpha-ketoglutarate dehydrogenase, malate dehydrogenase and citrate synthase. Main molecules regulating are ADP, Ca2+ and NADH+H. 

TCA cycle - Important Reactions and Applied Aspects



In this video I have explained all the high yield points about TCA cycle reactions. Macromolecules like carbohydrates, lipids and proteins ultimately converted to final common metabolic intermediate acetyl CoA. Acetyl CoA gets into citric acid cycle (TCA cycle or Krebs cycle) to release CO2 and the reducing equivalents NADH and FADH2 and GTP. 

Why Lactose is an End Product of Anaerobic Glycolysis?



In this video I have explained the reason for why lactate is the end product of glycolysis under anaerobic situation or in cell which do not have mitochondria like red blood cells (RBCs). I have also briefly explained glycolysis that is oxidation of glucose to pyruvate and the energy yield from oxidation of glucose to pyruvate. 

Vitamin K - High Yield Review



In this video I have explained all the high yield points about vitamin K. I have explained the sources of vitamin K1 phylloquinone, vitamin K2 menaquinone, vitamin K3 menadione. The major sources are green leafy vegetables like spinach, significant source of vitamin K is bacterial flora. Main function of vitamin K is post translational carboxylation of glutamate to make gla. Clotting factors activation, activation of protein C and protein S, matrix gla proteins, osteocalcin in osteobalsts. Vitamin K helps in clotting process, bone health, preventing atherosclerosis and thrombosis. Vitamin K deficiency can lead to hemorrhagic disease of newborn or excess bleeding adults. 

How to Differentiate Cobalamin Deficiency from Folate Deficiency



In this video I'm explaining one of the most important and high yiled concept that is to differentiate between folate and cobalamin deficiency. Both the deficiencies leads to megaloblastic anemia and macrocytic RBCs but the clinical sigens and laboratory test can differentiate both the deficiencies. While explaining that I have also briefly explained the causes for deficiency of folate and cobalamin like overcooking of greens, pernicious anemia, folate trap.

Role of Vitamins in Bone Health



In this video I have briefly explained the role of vitamins in bone health. Specially role of vitamin K I have explained little more than the role of vitamin D and vitamin C. Vitamin K is needed for the gamma-carboxylation of osteocalcin to increase bone density. Bone density is proportional to the levels of carboxylated osteocalcin in the blood. 

Vitamin D - Activation, Function, Regulation


In this video I have explained the activation of vitamin D in the liver and kidney by hydroxylation process. Regulation of active vitamin D3 by PTH (parathyroid hormone), 24-hydroxylase and active vitamin D itself. Main function of vitamin D is to regulate calcium and phosphate levels in the blood. Other functions of vitamin D have been revealed by recent research like its role in preventing tumor formation, immune mechanism, insulin sensitivity.
Sunlight exposure is the source of vitamin D from our skin.

Absorption of Monosaccharides



In this video I have explained the process of absorption of monosaccharides in the duodenum and jejunum. Two transporters absorb monosaccharides like glucose, galactose and fructose, they are SGLT-1 and GLUT 5. SGLT-1 works in a sodium dependent manner and GLUT 5 works in sodium independent manner. GLUT 2 on the basal side transport these monosaccharides out into portal vessel. Na-K ATPase on the basolateral side helps SGLT-1 to function optimally. Lactose intolerance can occur due to lactase deficiency leading to osmotic diarrhea, abdominal cramps and flatulence. Carbohydrate indigestion, and carbohydrate dumping could lead to osmotic diarrhea. 

Digestion of Carbohydrates



In this video I have explained all high yield points about the digestion of carbohydrates. The major carbohydrates in the diet are starch, lactose and sucrose. Salivary alpha-amylase digest starch in the mouth into alpha-dextrin. Alpha dextrin further digested into oligosaccharides, maltose and isomaltose by pancreatic alpha-amylase. Specific disaccharidases like maltase, isomlatase, lactase and sucrose will take care of maltose, isomaltose, lactose and sucrose, respectively. The oligosaccharides are digested by alpha-glucosidase into individual glucose molecules one at a time.

Tocopherol (vitamin E) - All high yield points



In this video I have done a high yeild review on tocopherol the vitamin E. Vitamin E is a collective term for tocopherols and tocotrienols. Alpha tocopherol is biologically most active form of tocopherol and is a powerful reactive oxygen species scavenger, that is tocopherol has antioxidant property. tocopherol prevents lipid peroxidation. it prevents LDL oxidation and thereby atherosclerosis. Deficiency of tocopherol is seen in lipid malabsorption disorders like cystic fibrosis. Tocopherol deficiency leads to spinocerebellar ataxia, hemolytic anemia, skelatal myopathy, retinopathy, polyneuropathy.

Thiamine (vitamin B1) - All high yield points for exam



In this video I have done a high yield review about all the important points related to thiamine that is vitamin B1. Different types of beri beri the deficiency disease of thiamine were explained. the causes for thiamine deficiency is explained.

Pyridoxine (vitamin B6) - High yield review



In this video I have done a high yield review on pyridoxine vitamin B6 - it includes its forms, active form, biological functions, causes for deficiency, deficiency ,anifestation and the diseases where supplementing pyridoxine is beneficial. 

Niacin (vitamin B3) - All high yield points



In this video I have explained all high yield points about niacin vitamin B3. Niacin deficiency causes pellagra with 3 D's diarrhea, dermatitis and dementia. 

Riboflavin (vitamin B2) - High yield review


In this video I have explained all high yield points about riboflavin vitamin B2.
Riboflavin (vitamin B2) is part of the vitamin B group. It is the central component of the cofactors FAD and FMN and as such required for a variety of flavoprotein enzyme reactions including activation of other vitamins.

How to calculate Km and Vmax using Lineweaver Burk plot



In this video I have explained how to calculate Km and Vmax of an enzyme in Lineweaver Burk double reciprocal plot.

The Lineweaver–Burk plot was widely used to determine important terms in enzyme kinetics, such as Km and Vmax, before the wide availability of powerful computers and non-linear regression software. The y-intercept of such a graph is equivalent to the inverse of Vmax; the x-intercept of the graph represents −1/Km. It also gives a quick, visual impression of the different forms of enzyme inhibition.