NEET MDS Shorts
733977
BiochemistryUric acid is a purine derivative, increased by purine salvage reactions that convert purines, purine ribonucleosides, and purine deoxyribonucleoside to mononucleotides (incorrect answer 4).
Such salvage reactions require much less energy than de novo synthesis (incorrect answers 1, 2). The liver is the major site of purine nucleotide biosynthesis and provides excess purines for other tissues that cannot synthesize purines.
A defect in hypoxanthine-guanine phosphoribosyl transferase, one of the enzymes of purine salvage, is responsible for purine overproduction and subsequent hyperuricemia observed in Lesch-Nyhan syndrome.
625069
Biochemistryâ-oxidation of fatty acid occursin Mitochondria
570639
Biochemistry
The principal role of Vitamin E in the prevention of oxidative damage is to potentiate the action of superoxide dismutase
199336
BiochemistryThe concentration of ketones is increased in body due to:
1. Starvation
2. High fat diet
3. Diabetes mellitus
324676
BiochemistryMethionine is sulphur containing AminoAcid
585492
BiochemistryRate limiting step of Kreb's cycle is catalysed by isocitrate dehydrogenase
409391
BiochemistryThe enzyme phosphatidate phosphatase converts phosphatidic acid to diacylglycerol during synthesis of triacylglycerides.
The function of adipose tissue is the storage of fatty acids as triacylglycerols in times of plenty and the release of fatty acids during times of fasting or starvation.
Fatty acids taken in by adipocytes are stored by esterification to glycerol-3-phosphate. Glycerol-3-phosphate is derived almost entirely from the glycolytic intermediate dihydroxyacetone phosphate through the action of glycerol-3-phosphate dehydrogenase. Glycolytic enzymes are active in adipocytes during triglyceride synthesis, but those of glycogen degradation (low levels in adipocytes) and gluconeogenesis (ie, glucose-6-phosphatase) are not.
Glycerol kinase is not present to any great extent in adipocytes, so that glycerol freed during lipolysis is not used to reesterify the fatty acids being released.
The enzyme triacylglyceride lipase is turned on by phosphorylation by a cyclic AMP-dependent protein kinase following epinephrine stimulation.
575979
Biochemistry
The formation of oxyhemoglobin is influenced by
1. pH
2. CO2 concentration
3. Temperature