Complementary copy for who preparing for Biochemistry Common Entrance Examinations (like-AURPGCET, CSIR UGC NET, GATE etc)
Synopsis of Biochemistry -
Saturday, July 10, 2010
CSIR NET Life science 2010 paper (Memory based)
This is CSIR NET Life science 2010 paper (Memory based). it is very useful to CSIR aspirants.
CSIR net june2010 with answers -
CSIR net june2010 with answers -
WHILE YOU READ BIOCHEMISTRY SCAN FOR THE FOLLOWING Metabolic tips
1. Three compulsory lists that must be at your tips-
· Ketogenic and Glucogenic amino acids.
· Essential and Nonessential amino acids.
· Basic, Acidic, Sulphur containing amino acids.
2. Regulatory Enzymes of pathways e.g.
· Citrate synthesis in citric acid cycle.
· Phosphofructokinase in Glycolysis.
· Pyruvate dehydrogenase in Pyruvate Oxidation.
· Pyruvate Carboxykinase in Gluconeogenesis.
· Glycogen Synthase in Glycogenesis.
· Phosphorylase in Glycogenolysis.
· G6PD in PPP.
· HMG CoA reductase in cholesterol synthesis.
3. Search for ATP estimates e.g.,
· 8 ATP’s per Glucose molecule in Glycolysis under aerobic conditions.
· 30 ATP’s per Pyruvate molecule entering citric acid cycle.
· 129 ATP’s per palmitate undergoing b-oxidation.
4. Look for regulatory molecules and feedback inhibitions e.g.,
· Glucose-6-phosphate inhibition on hexokinase.
· Citrate’s inhibitory effect on phosphofructokinase 1.
· Alanine’s inhibitory effect on Pyruvate kinase.
· Acetyl CoA’s inhibitory effect on Pyruvate dehydrogenase.
· Long chain acyl CoA’s inhibitory effect on Acetyl CoA carboxylase.
5. Look for subcellular organelles where the reactions specifically occur.
· Enzymes of citric acid cycle in mitochondrial matrix.
· Enzymes of Glycolysis in cytosol.
· Enzymes of pentose phosphate pathway in cytosol.
· Enzymes of denovo synthesis of fatty acids in cytosol.
· Enzymes of fatty acid oxidation in mitochondria.
6. Always have a clarity regarding precise role of various lipoproteins.
· HDL is cholesterol scavenger.
· Chylomicrons carry dietary cholesterol.
· VLDL are vehicles of transport of triacylglycerol from the liver to extrahepatic tissues.
7. Vitamins and their role as coenzymes e.g.,
· Thiamine in oxidative decarboxylation.
· Niacin in dehydrogenase reactions.
· Pantothenic acid in CoA.
· Pyridoxal phosphate in muscle phosphorylase.
· Biotin in carboxylase enzymes.
· Vitamin B12 to produce succinyl CoA.
· Folate in transfer of one-carbon units.
8. Products that accumulate in metabolic disorders e.g.,
· Homogenisate in urine of Alkaptonuria patients
· Phenyl acetyl glutamine in phenylketonuria.
· Xanthurenate in Vitamin B6 deficiency.
· Branched chain ketonuria in Mapple syrup urine disease.
· Glucose-6-phosphates in von Gierkes.
· Hepatic fructokinase in essential fructosuria.
· Galactose-1-phosphate uridyl transferase in Galactosemia.
· Cystathionine-b-synthase in homocystinuria.
10. Where nadh forms, where NADPH forms, where FADH2 forms, where substrate level phosphorylation occurs e.g.,
· FADH2 in succinate dehydrogenase in citric acid cycle.
· NADH in all degradative reactions.
· NADPH in all synthetic reactions.
Friday, July 9, 2010
Nitrogen Metabolism & Seed Germination
Every living cell must have a supply of amino acids constantly available for diverse synthetic processes, especially protein synthesis.
These amino acids may be derived by synthesis from simple substances (Glucose as a carbon source & ammonium ion as a nitrogen source (or) by absorption from the surrounding environment).
The biosynthetic pathways leading to amino acids and nucleotides share a requirement for nitrogen. Because soluble, biologically useful nitrogen compounds are generally scarce in natural environments, most organisms maintain strict economy in their use of ammonia, amino acids, and nucleotides.
Indeed, as we shall see, free amino acids, purines, and pyrimidines formed during metabolic turnover of proteins and nucleic acids are often salvaged and reused. We first examine the pathways by which nitrogen from the environment is introduced into biological systems.
Germination is the process whereby growth emerges from a period of dormancy. The most common example of germination is the sprouting of a seedling from a seed of an angiosperm or gymnosperm. However, the growth of a sporeling from a spore, for example the growth of hyphae from fungal spores, is also germination. In a more general sense, germination can imply anything expanding into greater being from a small existence or germ.
Phytohormones or Plant Growth Hormones are ....
Plant hormones (also known as phytohormones) are chemicals that regulate plant growth, which, in the
Plant hormones are signal molecules produced within the plant, and occur in extremely low concentrations. Hormones regulate cellular processes in targeted cells locally and when moved to other locations, in other locations of the plant. Hormones also determine the formation of flowers, stems, leaves, the shedding of leaves, and the development and ripening of fruit.
Plants, unlike animals, lack glands that produce and secrete hormones, instead each cell is capable of producing hormones. Plant hormones shape the plant, affecting seed growth, time of flowering, the sex of flowers, senescence of leaves and fruits.
They affect which tissues grow upward and which grow downward, leaf formation and stem growth, fruit development and ripening, plant longevity, and even plant death. Hormones are vital to plant growth and lacking them, plants would be mostly a mass of undifferentiated cells.
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Sunday, July 4, 2010
Lecture - 7 Enzyme Mechanisms II
Lecture - 6 Enzyme Mechanisms I
Lecture - 5 Enzymes I
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