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270 Cards in this Set
- Front
- Back
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Cori cycle
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The cycle of biochemical reactions involving a two-way flow of products between muscles and the liver. During the cycle, muscle glycogen is broken down to lactic acid, transported to the liver and converted to glucose. The glucose can either be passed back to the muscles to serve as an energy source or be stored in the liver as glycogen
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Citrate
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Citrate is the first intermediate of the citric acid cycle and tricarboxylic acid (TCA) cycle. It also plays an important role in fatty acid synthesis which takes place in the cytoplasm. It acts as a carrier of acetyl-CoA, the construction material for fatty acids.
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Acetyl CoA
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Acetyl-coenzyme A, a high-energy ester of acetic acid that is important both in the tricarboxylic acid cycle and in fatty acid biosynthesis.
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Transamination
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Enzymatic transfer of an amino group from an a-amino acid to an a-keto acid.
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Phenylketonuria
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A human disease caused by a genetic deficiency in the enzyme that converts phenylalanine to tyrosine. The immediate cause of the disease is an excess of phenylalanine, which can be alleviated by a diet low in phenylalanine.
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Phosphogluconate pathway.
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Another name for the pentose phosphate pathway. This name derives from the fact that 6-phosphogluconate is an intermediate in the formation of pentoses from glucose.
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Glutamate dehydrogenase
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an enzyme, present in most microbes and the mitochondria of eukaryotes, converts glutamate to α-Ketoglutarate, and vice versa.
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Glutamine synthetase
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is an enzyme that plays an essential role in the metabolism of nitrogen by catalyzing the condensation of glutamate and ammonia to form glutamine.
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aminopeptidase
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An enzyme produced by the intestinal mucosa which completes the process of protein digestion by hydrolyzing the amino-terminal amino acids of peptides and some proteins, after the initial breakdown of protein to peptides has already taken place.
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Proteosome
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A large proteolytic particle found in the cytoplasm and nucleus of all eukaryotic cells that is the site for degradation of most intracellular proteins.
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aminotransferase
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An enzyme that catalyzes the reversible transfer of an amino group from an α-amino acid to an α-keto acid using the coenzyme pyridoxal phosphate.
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Carbamoyl phosphate
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is an anion of biochemical significance. In land-dwelling animals it is an intermediary metabolite participating in the nitrogen disposal through in the urea cycle and the synthesis of pyrimidines.
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Oxidative deamination
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A reaction involved in the catabolism of amino acids that assists their excretion from the body. An example of an oxidative deamination is the conversion of glutamate to α-ketoglutarate, a reaction catalysed by the enzyme glutamate dehydrogenase.
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ingested plants
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Origin of components of amino acid synthesis
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glutamate and glutamine syntheses.
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What determines availability of amino groups for amino acid production
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tryptophan and histidine
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Glutamine amide sidechain donates to
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aspartate
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can be converted oxaloacetate
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Aspartate can be converted to
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asparagines, methionine, threonine, lysine.
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Threonine can be converted to
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isoleucine.
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Pyruvate can be converted to
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valine, alanine, leucine
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Ribose 5-phosphate can be converted to
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histidine
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Phosphoenolpyruvate and erythrose 4 phosphate can be converted to
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phenylalanine, tyrosine, tryptophane.
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Pheylalanine can be converted to
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tyrosine
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Alpha-ketoglutarate can be converted to
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glutamate
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Glutamate can be converted to
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glutamine, proline, and arginine
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3 phosphoglycerate can be converted to what amino acids
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serine
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Serine can be converted to what amino acids
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cysteine and glycine.
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What are the three alpha-ketoacids that can be converted to alpha-amino acids
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alpha-ketoglutarate, oxaloacetate and pyruvate.
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What other nonsessential AAs are directly synthesized from glutamate
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arginine and proline.
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What is the alternative synthesis of glycine from scratch
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synthesis of activated one carbon units of tetrahydrofolate.
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Homocysteine
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methionine
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A small molecule precursor tripeptide of glutamate , cysteine and glycine which protects against oxidative damage
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Glutathione.
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A substrate for synthesis of nitric oxide, a free radical gas and short lived signaling molecule
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arginine
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Heme-containing proteins
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myoglobin, hemoglobin, catalase, peroxidase, cytochrome c
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First X- crystallographic structure of globular proteins produced
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myoglobin structure
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Porphyrine ring can be synthesized from
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glycine
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In the synthesis of phorphyrin ring glycine condenses with
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succinyl coA (in the mitochondria)
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In porphyrin synthesis two tm-aminolevulinate condenses to
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porphobilogen
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In porphyrin synthesis how many porophorbilogen condense to tetrapyrrole
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four
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How is heme broken down by
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bilivedin reductase
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A disorder due to deficiencies in the heme biosynthesis porphyrias due to insufficient cosynthase which results in skin sensitive to light
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congenital erythropoietic porphyria.
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A disorder due to deficiencies in the heme biosynthesis porphyrias which is the most
prevalent porphria overproduction of porphobilinogen, aminolevulinate and results in severe abdominal pain, neurological dysfunction “ madness” of king George during American revolution. |
acute intermitten porphyria
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Protein degradation begins in the
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stomach by pepsin
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Pancreatic zymogens degrade proteins to what to products in the stomach lumen
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amino acids and oligopeptides.
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How are oligopeptdes transported into the the intestinal cell
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by aminopeptidase (membrane enzyme) which breaks them down to tripeptides, dipeptides and amino acids.
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What enzyme in the intestinal cell catalyzes the transfer of tripeptides to the blood
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peptidase
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How many enzymes participate in the attachment of ubitiquitin to proteins to be degraded
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3
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What signals in protein dictate the half-lifes
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amino terminal residue, cyclin destruction boxes, and PEST sequences.
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Ubiquitin tagged proteins are degraded in the cell by a huge complex known as what
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Proteosome.
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What are the fates of amino acids released by protein digestion or turnover
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cellular respiration, fatty acid sysnthesis, glucose or glycogen synthesis, left intact for biosynthesis
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What provides nitrogen for amino acids and nucleotides or converted to urea and excreted
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amino groups
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Alpha amino groups can be converted into ammonium ions by oxidative deamination of
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glutamate
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The transfer of an alpha amino group from an amino acid to an alpha keto acid is called what
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transmination
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What enzyme catalyzes the transamination with pyridoxal phosphate cofactor pyridoxal phosphate (PLP) which contains a vitamin B6 (pyridoxine)
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aminotransferase
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Alpha amino acid and alpha ketoglutarate and converted to
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alpha- ketoacids and glutamate
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Aspartate and alpha ketoglutarate are converted to
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oxaloacetate and glutamate.
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Alaninin and alpha ketoglutarate are converted to
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pyrvate and glutamate.
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What are the two amino acids that can be directly deaminated
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serine and threonine
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Serine dehydratase catalyze
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serine to pyruvate and ammonia.
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Threonine dehydratase-threonine to
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alpha-ketobutyrate to ammonia
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Muscle must shuttle amino groups removed by deamination to
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liver
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Ammonium ion is converted into urea in most terrestrial vertebrates by
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urea cycle
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What are the two mechanisms for shuttling amino groups from muscle to liver
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alanine and glutamine shuttle.
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Urea cycle begins with formation of what activated amide
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carbamoyl phosphate in the mitonchodria.
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What catalyzes the transfer of activated carbomyol phosphate to amino acid ornithinine to form amino acid citrulline
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ornithine transcarbamoylase.
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What are the four fates of oxaloacetate synthesized from fumarate
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aspartate (transamination), citrate (condensation with acetyl CoA), pyruvate (decarboxylation), glucose (gluconeogenesis)
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What is the byproduct that links the urea cycle to the citric acid cycle
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fumarate
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Urea cycle, citric acid cycle and transmination of oxaloacetate are linked by
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fumarate and aspartate.
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All defects in the urea cycle lead to elevated levels of ammonia in the blood a condition known as
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hyperammonemia
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What are the two fates of carbon skeleton after the removal of alpha amino group
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ketogenic and glucogenic.
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What form acetyl CoA or acetoacetyl coA yielding ATP, ketone bodies or fatty acids with no net contributions to glucose
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ketogenic amino acids
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What two amino acids are solely ketogenic
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leucine and lysine
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Glucogenic amino aicds can give rise to
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glucose
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Fumarate can be formed from
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aspartate, phenylalanine, tyrosine
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Succinyl coA can be formed from
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isoleucine, methionine, threonine, and valine.
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Alpha ketoglutarate can be formed from
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arginine, glutamate, glutamine, histidine or proline
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Pyruvate can be converted to
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acetyl CoA and oxaloacetate
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Phophoenopyruvate can be formed from and to
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from oxaloacetate, to glucose,
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Before deamination phenylalanine is converted to
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tyrosine
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After deamination phenylalanine carbon skeletons are broken down to
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acetoacetate, fumarate.
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A defect in phenylalanine breakdown, a harmless disorder in which urine turns black after exposure to air
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alcaptonuria.
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Defective breakdown of valine, leucine, and isoleucine which leads to mental retardation
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maple syrup urine disease.
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A defective in conversion of phenylalanine to tyrosine which leads to mental retardation and death
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phenylketonuria
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Defective conversion of tyrosine to melanin, enzyme tyrosinase defective or deficient
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albinism
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What is nutrition
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the science of food, the nutrients and the substances therein, their action, interaction and balance in relation to health and disease, and the process by which the organism ingests, digests absorbs, transports, utilizes, and excretes food substances.
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diet
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provides energy and material needed to fuel, build and maintain all body cells.
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Nutrients
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the nourishing substances obtained from food that the body cannot make or makes in quantities too small to support life.
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What are the functional categories of nutrients
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Thoses that provide energy, promote growth and development, and those that regulate body processes.
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What makes a nutrient essential
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a decline in health may occur if its not included in diet, if restored after being omitted-health affected should normalize, a specific biological function must be identified
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What is the 2nd leading cause of preventable death in America
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obesity
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A health women or man must consume what percent of carbohydrates
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less than 1 percent
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What should be the highest consumed vitamin in both man and women
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water
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Calorie
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Amount of energy in foods; heat energy required to raise temp of 1 gm of H2O 1°C
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Kilocalorie
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Heat energy required to raise temp of 1000 gm of H2O 1°C
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Reduced biochemical function is characterized as what
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undernutrition
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Having lots of vitamin A, iron, calories, obesity, type 2 diabetes and cancer can all result from
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overnutrition.
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What are the basic limitations of measuring nutrition status
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1) signs and symptoms not very specific 2) difficult to establish link 3) long lapse between initial development of poor nutritional health and clinical evidence
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The body uses energy for what 3 general purposes
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Basal metabolism (REE), Physical activity, Digestion, absorption and processing ingested nutrients ( 1. Thermic effect of food (TEF) 2. Thermogenesis (NEAT))
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Basal metabolism rate
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the rate at which energy is used by an organism at complete rest, measured in humans by the heat given off per unit time, and expressed as the calories released per kilogram of body weight or per square meter of body surface per hour.
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what factors are involved in Basal Metabolism
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thyroid hormones, nervous system activity, pregnancy, caffeine and tobacco usage
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What is thermogenesis
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heat production in response to nonvoluntary activity triggered by overfeeding or cold.
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What is adaptive thermogenesis
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non exercise activity in thermogenesis.
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Why is brown adipose tissue important
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fat used in adaptive thermogenesis in infants and hibernating animals to create heat.
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What is direct calorimetry
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a why to estimate energy needs. Measures amount of body heat released by a person in an insulated chamber.
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What is indirect calorimetry
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a way to estimating energy needs. Measures oxygen output rather then heat output.
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What is the formula used to convert the gas exchange value to energy use
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moles of CO2 expired/Moles of 02 consumed.
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What is the rough guidelines for energy needs in sedentary females and older adults
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1600
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What is the rough guideline for energy needs for children, teen girls, active women and most men
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2200
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What is the rough guideline for energy needs for teens boys, active men, and very active women
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2800
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Body mass index( BMI) is calculated using- weight and height only.
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Weight / height squared.
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How can one convert the body weight to kilograms
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pounds divided by 2.2
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How can one convert height in inches to meters
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inches divided by 39.4
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What is the gynoid ( pear shaped)
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lower-body fat distribution
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What is the android (apple shape)
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upper-body fat distribution
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What is obesity
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nurture allowing nature to express itself- kind like an accident waiting to happen.
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Is it true that both genetics and environment increase risk for obesity
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true
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what is EAR
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est.Average req.-meets need of 50% individuals in certain age/sex groups
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RDA
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meets need of 98% of individuals
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Al
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adequate intake-maintain nutritional state
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EERS
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Est.Energy requirm.-average need for different age groups
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UL
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tolerable upper intake levels
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What is the basis of a health diet
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Variety, Balance and Moderation
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True or false, The Dietary Guidelines are designed to meet nutrient needs while reducing the risk of obesity , hypertension, CV disease, type 2 diabetes, alcoholism, and foodborne illness.
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true
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How often are the dietary guidelines updated and published
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every 5 years.
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What are the divisions of life cycle nutrition
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Infancy, age 1 to 5 years, age 6 to 12 years, adolescence,adulthood (19-50, 51-70), older adulthood (> 70)
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When does Prenatal Growth and Development take place
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between 38-42 wks
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What are the three stages of prenatal development
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first trimester, second trimester, third trimester,
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What are the three pregnancy outcomes
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normal, low birth weight, and small for gestational age
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What is the Diet and Exercise Plan for Pregnant Women
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A prenatal with 600 micrograms of folic acid and at least 27 milligrams of iron, Iron during last two trimesters,B12 for vegans,regular dental check ups.
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What are the factors Affecting Pregnancy Outcomes
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Low SES (social economic status), prenatal care, age, Birth spacing, Prenatal ketosis, Body weight, Lifestyle factors
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What are the physiological changes during pregnancy
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pregnancy induced hypertension HTN, pregnancy induced gingivitis, anemia,
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What is the single best indicator for Assessment of Growth & Development from infancy to adolescence
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growth
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Overfeeding during infancy may increase the number of
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adipose cells
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Do not restrict fat in diet before the age of
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2
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True or false Poor infant-parent interaction is common culprit (cause) of failure to thrieve in infants
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true
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What are the Infant Nutrition Health Problems
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Colic, Diarrhea, Milk allergy,Iron deficiency anemia, Gastroesophageal Reflux
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What are the Common Nutritional Problems in Preschoolers
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Iron deficiency anemia, constipation, dental caries
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What are the Common Nutritional Problems in School Aged Children (ages 6-12)
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Type 2 Diabetes and Overweight and Obesity.
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what occurs in Adolescence
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growth spurts , secondary sexual characteristics, lean and fat tissue development
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What Nutritional Problems occur during adolescence
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poor consumption of fruits and veggies, high fat/high sodium diets, lack of calcium intake, Iron deficiency
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What are the three main eating disorders-
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Anorexia Nervosa, Bulimia Nervosa,Obesity
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What is anorexia nervosa
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Refusal to eat is the hallmark, Distorted body image--FEAR of weight gain, Absence of at least 3 consecutive menstrual cycles
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What is bulimia nervosa
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Purging or Nonpurging bulimia. At or above normal weight, Constant thoughts of food, Binge purge cycles
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Demineralization of teeth, hypersensitive teeth and eventual erosion or decay is caused by what
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bulimia nervosa
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From a nutrition standpoint adulthood is divided into parts
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Young Adulthood (19-50); Middle Adulthood (51-70); Older Adulthood (>70).
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The diet for the adult years is like what
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Consume a variety of nutrient dense foods; rich in fiber, Maintain body weight at a healthy range, Practice safe food handling when preparing food, Decrease sodium; adequate intake of potassium
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True or false, People over age 50. Consume vitamin B12 in its crystalline form (i.e., fortified foods or supplements)
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true
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True or false, Older adults, people with dark skin, and people exposed to insufficient ultraviolet band radiation (i.e., sunlight). Consume extra vitamin D from vitamin D-fortified foods and/or supplements
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true
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What are the recommended carbohydrate dietary guidelines for Americans
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dietary fiber is important for laxation, constipation may affect up to 20 percent of people over 65 years of age, older adults should choose to consume foods rich in dietary fiber.
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True or false, Individuals with hypertension, blacks, and middle-aged and older adults. Aim to consume no more than 1,500 mg of sodium per day, and meet the potassium recommendation (4,700 mg/day) with food.
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true
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What are the Recommended dietary practices as we age
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Decrease in total energy consumption.Increase nutrient density of diet, Adequate dietary fiber; 6-8 cups of fluids, Protein from lean meats(B6 and zinc)
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What makes up a ribonucleoside
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ribose and base
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What makes up a ribonucleotide
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triphosphate, ribose and base
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Nucleotides are activated precursors of
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polynucleotides
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What nucleotides are essential components of signal transduction
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cAMP, cGMP; ATP + kinases; GTP + GTPases .
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What nucleotide derivatives participate in biosynthetic processes
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UDP-glucose in glycogen formation; CTP, phospholipids
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What amino acids serve as scaffolds for assembly of ring systems of bases
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Aspartate and glycine
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What amino acids provide sources of amino (-NH2) groups of bases
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Aspartate and glutamine
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What is the Salvage pathway
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a class for nucleotide biosynthesis were pre-formed bases are recovered, reconnected to a ribose
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What is the De novo pathways
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pathways for nucleotide biosynthesis were Nucleotides are synthesized from simpler compounds (amino acids, ATP, CO2)
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What do the De novo pathways and salvage pathways have in common
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both use the activated ribose (PRPP)
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Which envolved first ribonucleotides or deoxyribonucleotides
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ribonucleotides
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In the de novo pathways, pyrimidine rings are assembled from what
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bicarbonate, ammonia, and aspartate
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What is formed first in the pyrimidine biosynthesis
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pyrimidine bases is assembled first, then attached to a phosphoribose
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How is purine synthesized
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purine bases is synthesized directly onto a phosphoribose
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What is the function of carbamoyl phosphate synthetase I
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function in the mitochondria and urea cycle.
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What is the function of carbamoyl phosphate synthase II
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Catalyzes synthesis of carbamoyl phosphate, used in cytosol and pyrimidine metabolism
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What enzyme catalyzes the hydrolysis of glutamine to yield glutamate and ammonia
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carbamoyl phosphate synthetase
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How many sites does carbamoyl phosphate synthetase have
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glutamine hydrolysis site, bicarbonate phosphorylation site, and carbamic and phosphylation site.
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What is the function of aspartate transcarbamoylase (ATCase)
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catalyze carbamoyl phosphate + aspartate formation to carbamoylaspartate in step two of de novo synthesis of pyrimidines.
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How is ATCase inhibited
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by an end-product of the overall pathway, CTP (feedback inhibition) via allosteric regulation of oligomer
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What is the function of pyrimidine phosphoribosyl-transferase
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enzyme that catalyze the formation of Orotidylate (pyrimidine nucleotide) from orotate and Phosphoribosyl-pyrophosphate (PRPP) transfer and pyrophosphate release in pyrimidine synthesis
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What is Phosphoribosyl-pyrophosphate (PRPP)
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a molecule synthesized from ribose-5-phosphate, derived from the pentose phosphate pathway, by the addition of pyrophosphate (from ATP) that is used in the synthesis of pyrimidine biosynthesis.
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What is UMP (uridylate)
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is pyrimidine nucleotide synthesized by orotidylate decarboyxalase used the use of cofactors or prosthetic groups.
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What is the correct order of nucleoside interconversion-
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UMP > UDP > UTP
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CTP is formed by amination of
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UTP
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What amino acid is used in UTP formation from CTP
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glutamine (replacement of a carbonyl group by an amino group)
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UMP can be interconverted to what other things-
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UMP > dUMP > TMP
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TMP is formed by methylation of
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dUMP
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What is the function of Thymidylate synthase
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catalyzes the conversion of deoxyuridinemonophosphate (dUMP) to thymidylate (TMP)
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What is the methylated analog of uracil base found DNA
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thymine
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What is the function of N5,N10-methylenetetrahydrofolate
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donate methyl group to thymine
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What is the function Dihydrofolate reductase
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catalyzes the regeneration of dihydro- to tetrahydrofolate using NADPH as the reductant, also used in the alternative synthesis of glycine
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One-carbon units can be formed de novo from
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from carbohydrates by synthesis of --serine from 3-phosphoglycerate, followed by conversion of serine to glycine
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What is the function of thymidylate synthase
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synthesize thymidylate (TMP) from deoxyuridine monophosphate (dUMP) and N5,N10-methylenetetrahydrofolate
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What two anticancer drugs have targets in TMP synthesis
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Fluorodeoxyuridylate (F-dUMP) from fluorouracil) and aminopterin and methotrexate (amethopterin)
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What is the function of Fluorodeoxyuridylate (F-dUMP)
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an irreversible or suicide inhibitor of thymidylate synthase
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What are the functions of Aminopterin or methotrexate
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are analogs of dihydrofolate that act as competitive inhibitors of dihydrofolate reductase
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How does the Suicide inhibition of thymidylate synthase by fluorodeoxyuridylate work
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fluorodeoxyuridylate replaces deoxyuridine monophosphate (dUMP) and acts at the substrate
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What was the first enzyme target for chemotherapy
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Dihydrofolate reductase-
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What is Aminopterin
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folate analog, first anticancer drug used; binds 1000X more tightly, new generation drug Methotrexate (Amethopterin) binds even tighter, better clinical characteristics
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What two types of enzymes degrade Pyrimidines from nucleic acids or the energy pool
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Nucleotidases, Pyrimidine Nucleoside Phosphorylases-
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How do Nucleotidases work
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hydrolysis removes phosphate in pyrimdine catabolism, yielding nucleosides and phosphate
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How do Pyrimidine Nucleoside Phosphorylases work
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phosphorolysis removes sugars for reuse,yielding the bases for salvage or degradation
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After loss of the amino group, all three pyrimidine bases (uracil, thymine, cytosine) undergo ring cleavage yielding
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b-amino acids, ammonia and carbon dioxide
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True or false, Catabolism of pyrimidine bases occurs in the liver by reduction in contrast to
Purine catabolism,which is by oxidation |
true
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What is the First step in the Catabolism of pyrimidine bases
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ring cleavage through reduction by NADPH
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What are Groups released in pyrimidine bases catabolism
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carbon dioxide, ammonia, and beta amino acids
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What is purine synthesized from
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CO2, glycine, aspartate, glutamine, N10-formyl tetrahydrofolate,
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Purine ring structure can be converted into what
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IMP.
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IMP can be converted into what
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ATP and GTP
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What provides the foundation for step-by-step assembly of purine base
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phosphoribosylpyrophosphate (PRPP)
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What is the function of the enzyme glutamine phophoribosyl amidotrannsferase
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conversion of PRPP to 5-phosphoribosyl-1-amine by displacement of pyrophosphate by ammonia in purine synthesis
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De novo pathway for purine nucleotide synthesis has how many steps
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9
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What is the first step of de novo synthesis of purines—
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glycine is coupled to amino group (ribose-NH2 , phosphoribosyl-amine) using ATP.
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In step of de novo synthesis of purines what is the function of N10-formyltetrahydrofolate
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transfers formyl group to the amino group of the glycine residue.
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What is formylglycinamide ribonucleotide
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an inner amide group that is phosphorylated and converted to an amidine ( formylglycinamidine ribonucleotide) by the addition of ammonia derived from glutamine in purine synthesis
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What forms the five membered imidazole ring (5-aminoimidazole ribonucleotide) during step 4 of de novo synthesis of purines
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an intramolecular coupling reaction.
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What adds first to the exocyclic amino group( 5-aminoimidazole ribonucleotide) in step 5a of de novo synthesis of purines
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activated bicarbonate
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What happens in step five B of the conversion of the inner amide to amidine in purine de novo synthesis
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bicarbonate is transferred to a carbon atom of the imidazole ring by a rearrangement.
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What is the function of aspartate in de novo synthesis of purines
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displacement of inorganic phosphate (pi) from the phophorylated imidazole carboxylate.
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What intermediate contains all but one atom ( a formyl group from N10-formyl tetrahydrofolate) in purine biosynthesis
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aspartate
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What is eliminated in step 7 of de novo purine synthesis-
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fumarate ( a citric acid cycle intermediate)
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In step 8 of purine synthesis a second formyl group form N10-formyltetrahydrofolate is added to the exocyclic amino from what amino acid
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glutamine
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What does the final intermediate cyclizes with to form inosinate (IMP) ,the common precursor of AMP and GMP in purine synthesis
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loss of water
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AMP and GMP are synthesized by separate branches in two steps from common precursor known as what
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insoinate (IMP)
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What is the function of adenylsuccinate synthetase
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substitution of carbony oxygen atom at C-6 with an amino group from aspartate in conversion of AMP from IMP step 1.
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What is the function of fumarate in AMP synthesis from IMP
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fumarate is eliminated leaving behind alpha amino group of aspartate.
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The conversion of ribonucleotides to deoxyribonucleotides is catalyzed by what enzyme
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ribonucleotide reductase.
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What is the ultimate source of electron for reduction of ribonucleotides to deoxyribonucleotides
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NADPH.
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Deoxynucleotides are formed by reduction of ribonucleotides through a remarkable free radical mechanism known as what
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tyrosyl radical, unpaired e delocalized onto aromatic ring
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What four ribonucleotides can be reduced to deoxy form
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A, G, U, C
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What is the salvage pathway for purine bases
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free purine bases are salvaged for ATP, RNA/DNA synthesis derived from turnover of nucleotides or the diet.
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What is the function of adenine phosphoribosyltransferase in the purine salvage pathway
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the conversion of adenine and PRPP to adenylate and PPi
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What is the function of the hypoxanthine-guanine phosphoribosyltansferase in the purine salvage pathway
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conversion of guanine and PRPP to guanylate and PPi, and conversion of hypoxanthine and PRPP to inosinate and PPi.
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Inosinate (inosine monophosphate, IMP) is the precursor of what
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guanylate and adenylate
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What is the similar pathway for pyrimidine base uracil in the salvage pathway
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pyrimidine phosphoribosyltransferase will reconnect uracil to PRPP, though not cytosine.
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Purine bases (AMP, IMP, hypoxanthine and guanine) are first converted into what before excretion
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xanthine then urate.
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What is the function of xanthine oxidase
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catalyzes the formation of uric acid from xanthine, can treat gout
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What two pathological conditions results form disruption of nucleotide metabolism
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gout and lesch-nyhan syndrome.
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What is the disease in which urate the end product of purine base catabolism is excreted in urine but also present in serum
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gout
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What is the function the drug allopurinol
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treatment of gout, it is an inhibitor of xanthine oxidase.
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What disease in due to near complete lack of hypoxanthine-guanine phosphoribosyltransferase (HGPRT) and is characterized by compulsive, self-destructive behavior, mental deficiency and spasticity
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lesch-nyhan syndrome.
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What are the consequences of hypoxanthine-guanine phosphoribosyltransferase (HGPRT) loss
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elevated concentration of PRPP, marked increase in rate of purine biosynthesis by de novo pathway, and overproduction of urate which could lead to gout.
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What are the recurring motifs in metabolic regulation
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allosteric regulation, covalent modification, enzyme level modulation, compartmentalization, metabolic specialization
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What type of recurring motif has enzymes of committed steps
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allosteric regulation
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What type of recurring motif has rapid adjustment to signals (milliseconds to seconds)
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allosteric regulation
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Phosphorylation and adenylation are what type of recurring motifs
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covalent regulation (lasts seconds to minutes)
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The recurring motif often utilized by hormones is known as what
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enzyme level modulation (30 minutes to several hrs for effect).
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Glycolysis (cytoplasm), inner mitochondrial membrane (oxidative phosphorylation), B-oxidation (mitonchodrial matrix)—is what type of recurring motif
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compartmentation.
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The cori cyle which is an interplay between the live and muscle pyruvate regeneration to glucose is an example of recurring motif
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metabolic specializations of organs.
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In glycolysis what enzymes catalyzes the formation of fructose-1-6-bisphosphate from fructose-6-phosphate-
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phosphofructokinase
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What hormone signals a decrease in F-2, 6-BP in the liver when glucose in low slowing down glycoslysis
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glucagon.
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Phosphofructokinase can be inhibited by
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ATP and citrate
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What are the functions of F-2-6 BP and AMP in glycolysis
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inhibit the enzyme phosphofructokinase
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In the citric acid cycle, NAD+ and FAD are produced only if what is available for production of ATP by ATP synthase
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ADP
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Abundant ATP does what to the enzymes of citric acid cycle isocitrate and alpha-ketoglutarate dehydrogenases
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inhibits
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What is the committed step in pentose phosphate pathway
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dehydrogenation of glucose-6-phosphate regulated by NADP+, the electron acceptor.
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What is the key regulatory enzyme controlling rate of gluconeogenesis
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fructose-1-6-bisphophatase activated by citrate and inhibited by AMP and F-2,6-BP
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How are gluconeogenesis and glycolysis regulated
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reciprocally (one minimally while other highly active).
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How is the glycogen degradation and synthesis coordinately controlled
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by a hormone-triggered amplifying cascade so that the phosphorylase is active when the synthase is inactive and vice versa.
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How are glycogen synthesis and degradation enzymes regulated
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by phosphorylation and allosteric interactions.
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What are the two main functions of citrate in fatty acid synthesis
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transports acetyl coA out of mitochondria to cytosol and stimulates Acetyl CoA carboxylase, enzyme catalyzing committed step.
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What is the function of palmitoyl CoA in fatty acid synthesis
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inhibit the conversion of acetyl Coa to malonyl CoA.
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What is the function of carnitine in fatty acid degradation (beta oxidation)
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an intermediate in fat acid degradation that is converted to acyl carnitine by the enzyme carnitransferase I.
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The conversion of cartinine to acyl carnitine is inhibited by
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malonyl CoA.
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Glucose-6-phosphate, acetyl coA and pyruvate have what in common
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the all are key junctions and have major metabolic fates.
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Glucose-6 phosphate can be formed from what
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glucose, glycogen, pyruvate and glucogenic amino acids (gluconeogenic pathway).
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When is glycogen formed from glucose 6-phosphate
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when there is plenty of glucose-6-phosphate
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How is pyruvate converted to alanine or vice versa
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by transmination
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How is pyruvate converted to four-carbon alpha ketoacid oxaloacetate to replenish acid cycle
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by carboxylation
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Which organ has the highest concentration of glucose or glycogen
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muscle
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Which organ contains no triacylglycerols or mobilize proteins
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brain
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Which organ has the lowest glucose or glycogen concentration
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brain
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Which organ the highest mobilization of proteins
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muscle
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Triacylglycerols can be synthesized from what two molecules
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glucose and fatty acids in fat cells (adipose)
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What is the function of chylomicrons from the intestine
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transport/breakdown VLDL from the liver into fatty acids.
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What is the function of the hormone sensitive lipase
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triacylglycerols to glycerol and fatty acids in fat cells.
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What happens to glycerol food in the fatty cells
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goes to liver
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What happens to the fatty acids formed in fatty cells
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binds to albumin and goes to peripheral tissues.
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